Gulfstream IV in Bedford MA [Archive]

climber314

2nd Jun 2014, 02:03

This is interesting to read. Not sure if it has any bearing on this accident but it certainly raises some questions???

ERA12MA122 (http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20111226X15753)

Quote from NTSB Report RE 26 Dec 2011 Aircraft operated by SK Jets:

"The pilot’s financial pressure as the owner of the company likely influenced his decision to continue flight into deteriorating weather conditions. The operator’s business had declined several years before the accident as a result of economic recession. The accident helicopter had been leased days before the accident. The operator’s only IFR certified helicopter, which was the largest customer’s preferred helicopter, had been down for maintenance for 4 months while the operator attempted to secure loans for engine maintenance. The pilot was scheduled to meet with this customer in the coming weeks to obtain clarification about the customer’s requirements. The pilot was also aware that his largest customer had begun identifying other aviation companies that might better fulfill its needs. Thus, the pilot would have been highly motivated to complete trips as requested so that he could demonstrate the reliability of his service. Additionally, due to the economic downturn, the pilot’s company had lost millions of dollars during the 3 years before the accident. Therefore, the pilot likely wanted to make the most of every revenue generating opportunity."

SaturnV

2nd Jun 2014, 02:14

Never got airborne, rolled through the grass, collided with an antenna, ran through a chain link fence, and wound up in a gully. The gully is 2,000 feet from the end of the runway.

Lewis Katz, Co-owner of The Philadelphia Inquirer among seven killed in fiery Hanscom Field crash - Metro - The Boston Globe (http://www.bostonglobe.com/metro/2014/06/01/owner-the-philadelphia-inquirer-was-among-seven-people-killed-fiery-crash-hanscom-field-saturday-night/9oJFpf2pSqY3YGmSGp7EYL/story.html)

Blind Squirrel

2nd Jun 2014, 02:23

Deer are certainly a menace at many of the smaller fields in the U.S. I recall taking off one night from Morristown Municipal, a GA reliever field for NYC, when a herd of the buggers galloped across the runway at that awkward moment when I was going too fast to abort easily and not quite fast enough to rotate. My instinctive decision was to continue, and in the event I whistled over their heads without snagging an antler in the undercarriage.

I've some doubts about that being high on the probability list for this accident, though. In the first place Hanscom is a big and busy place, the main GA field for Boston, and also an Air Force base. It gets well over 100,000 movements per year, and is entirely enclosed by a high fence. Not impossible for something as big as a deer to get inside, to be sure, but not likely either. Secondly, if the accident aircraft did hit one or more deer, the carcase wouldn't be far away. I daresay someody would have said something about it by now.

susier

2nd Jun 2014, 06:43

OFBSLF

For what it's worth it was the middle section of this article which made me link the events.

Gulfstream G650 Accident Report | The House of Rapp (http://www.rapp.org/archives/2012/11/gulfstream-g650-accident/)

I have no idea if this has any bearing. The 450 looks to have had this issue way back, but it was corrected.

Global_Global

2nd Jun 2014, 07:47

Do N reg G-IVs have a black box on board?

CaptainProp

2nd Jun 2014, 08:00

Yes.

Part 91.609

c)(1)No person may operate a U.S. civil reg-istered, multiengine, turbine-powered airplane or rotorcraft having a passenger seating configura-tion, excluding any pilot seats of 10 or more that has been manufactured after October 11, 1991, unless it is equipped with one or more approved flight recorders that utilize a digital method of re-cording and storing data and a method of readily retrieving that data from the storage medium, that are capable of recording the data specified in Ap-pendix E to this part, for an airplane

(e) Unless otherwise authorized by the Admin-istrator, after October 11, 1991, no person may operate a U.S. civil registered multiengine, tur-bine-powered airplane or rotorcraft having a pas-senger seating configuration of six passengers or more and for which two pilots are required by type certification or operating rule unless it is equipped with an approved cockpit voice recorder

Astra driver

2nd Jun 2014, 15:53

Susier,

The issue with the G650/GIV you are referring to was the flight engineers incorrectly calculating the V2 speeds too high as well as making an incorrect assumption as to the stall AOA in ground effect. The net result of this was that the flight test crews were making aggressive rotations and steep climb outs in an attempt to not exceed the targeted V2 speeds and achieve the lowest possible balanced field length numbers for the aircraft. In the case of the 650 program this resulted in several wing drops during flight testing that were initially attributed to incorrect pilot technique, it took a tragic accident to "wake up" the engineers and get them to re-examine their calculations and uncover their erroneous assumptions regarding in ground effect stall AOA and V2 speeds. As Susier correctly points out the 650 accident had nothing to do with its flight control system, rather just incorrect performance calculations.

In the case of this GIV accident the fact that the aircraft appears to have come to rest (with considerable energy) some 2,000 ft beyond the departure end of a 7,011 ft runway makes me think this may not have been an aborted take-off over run. For a relatively short flight from Bedford to Atlantic city it is likely the aircraft only had a 10,000lb fuel load which would result in a BFL less than 4,000ft.

robbreid

2nd Jun 2014, 16:01

Aircraft involved was a 2000 build G-IVSP

It's AOC is SK Travel Limited Liability Corporation

SK Travel LLC is owned by Emil W. Solimine & Lewis Katz both from Livingston NJ

(Lewis Katz was on board)

Was based KILG, New Castle, DE

flytenr

2nd Jun 2014, 18:20

Susier,

I hope the Rapp.org article didn't give you the impression that Gulfstreams are poorly designed or prone to random stalls. They aren't.

What I was trying to convey with the post was that the G-IV test program suffered from a wing drop problem during OEI continued-takeoff testing whose cause was also attributed incorrectly by the engineers. In other words, it's not the aircraft that is at fault, but rather some of the assumptions made about it during testing.

Of course, that's exactly why testing is performed: to validate those assumptions. On the 650, they computed the wrong critical AOA in ground effect. On the G-IV, it's less clear about why the wing stall occurred (Mr. Johnson's account was given more than a quarter century after the test program ended), but they solved the issue with vortex generators.

My question was: give what happened with the G650, is it possible the IGE critical angle was also mis-computed on the G-IV? It seems that even Gulfstream didn't realize how different the critical AOA can be in ground effect versus in free air. I was not aware of that either. Nobody teaches you that the critical AOA is different, but if anything I would expect the angle to be higher, not lower, because performance is generally enhanced in ground effect.

Anyway, I hope that clears it up a bit. :)

owen robertson

2nd Jun 2014, 21:14

Has anyone noticed that the thrust reverser on the right engine in missing? Take a look at the picture:

http://c.o0bg.com/rf/image_960w/Boston/2011-2020/2014/06/02/BostonGlobe.com/Metro/Images/ryan_planecrash5_met.jpg

Looking at it close up, it is clear the the reverser is missing from the right engine, but is in place on the left engine.

Thoughts???

OldCessna

2nd Jun 2014, 21:32

I just watched the NTSB briefing at Hanscom.

They said the flap setting in the cockpit was set at 10 degrees

They have not located the cvr or data recorder as yet.

What I did see from the video was black tire marks for about 500-700 feet towards the end of the runway

With heavy darker tire marks for about a foot every 10 feet or so.

The engines looked intact and didn't see any reversers deployed. Not sure if they have clam shells on the RR Tays.

Captain had 18,000 hours and FO had 11,000 hours.

glendalegoon

2nd Jun 2014, 22:09

thank you old cessna

that seems to answer the flap question. though oddly put that the flaps were set in the cockpit to 10. wondering if the flaps were actually at 10.

but it does seem likely a late abort happened (I like the term abort better than reject, though I know reject has been around for so long).

does hanscom field have phenolic foam over run? (crushable concrete)

thanks again old cessna

OldCessna

2nd Jun 2014, 22:27

The NTSB briefer made specific mention that the cockpit flap setting was 10 degrees.

They will be checking the jackscrews and recorder to correlate.

The braking wheel marks on the runway were perfectly straight. The nose gear assembly was separated ahead of the aircrafts final resting spot and looked pretty intact.

NTSB just found the CVR and Data Recorder

OldCessna

2nd Jun 2014, 23:36

I have flown into Hanscom several times over the last 30 years. Its civilian and AF mix. Raytheon is nearby and a host other defense contractors.

Very good ATC although if you are not familiar with the locale it can be enlightening.

A familiar instruction is "Turn left at HoJo's"

Alright if you know Howard Johnsons has an orange roof!

Don't recall any foam or other stuff at end of runway.

It's a very busy airport but very well operated. My take!

Irish21

3rd Jun 2014, 00:14

the daily mail has photos of the crash site both from the air and ground...very detailed.

noneya

3rd Jun 2014, 00:35

glendalegoon

3rd Jun 2014, 00:56

noneya

thanks for the flap info. as you know there have been other types that did have configuration warning systems that didn't work right.

I imagine with fuel for atlantic city (not much) the plane might have even gotten airborne with no flaps (guess, no book), though I do not suggest anyone would have done this on purpose.

guessing the fuel req'd for atlantic city would have been less than 12000 lbs.

what do you think?

I couldn't link to the photos.

MikeNYC

3rd Jun 2014, 01:16

Hell of an overrun
http://bostonherald.com/sites/default/files/styles/full/public/media/2014/06/02/060214planemg011.jpg?c=512c6f66e845882d0a1bdc33b73a3baf

glitchy

3rd Jun 2014, 01:31

I'm not sure of the etiquette of just posting the names here, but I can't be the only one here who's been waiting and wondering if the phone is going to ring.

The article name says it all:

Crew in Hanscom crash identified (http://www.necn.com/06/02/14/Crew-in-Hanscom-crash-identified/landing.html?blockID=867327&feedID=11106)

JRBarrett

3rd Jun 2014, 01:53

Has anyone noticed that the thrust reverser on the right engine in missing? Take a look at the picture: http://c.o0bg.com/rf/image_960w/Bost...crash5_met.jpg Looking at it close up, it is clear the the reverser is missing from the right engine, but is in place on the left engine. Owen, The thrust reverse's are fully intact in the picture you posted. The only thing missing is the close out cover on the right actuator from what I can see. that seems to answer the flap question. though oddly put that the flaps were set in the cockpit to 10. wondering if the flaps were actually at 10 glendalegoon, On the GIV it is not uncommon to takeoff flaps 10 (think there was a whole tread on this some time ago). The aircraft also will give you a configuration warning if the flap are not at least 10 degrees and the throttles are advanced..... It is possible they forgot to set flaps 20 when they taxied out and only had them at flaps 10. It is very common to taxi in with flaps left at 10 so you can inspect the flap tracks actuators during the walk around. But I would suspect something else other than flaps, or in combination with, because even if they wanted 20 and only had 10 the aircraft would have flown with no problems, the runway is plenty long enough. J

Not a GIV pilot, but I am a GIV mechanic and avionics tech.

Yes, the R/H engine T/R is present. The outboard stang fairing that covers the actuator has been torn off, but both upper and lower doors are there. The lower door appears to be hanging down a few inches. Based on their appearance in the photo, it's difficult to say if they had been deployed or not. During ground maintenance, if we deploy them, and then shut off pressure from the hydraulic ground service cart -- after a few minutes, (once the pressure in the aircraft hydraulic lines has dropped to zero), the doors can be pushed closed by hand. Takes a bit of muscle power, but definitely do-able.

I would think that with the disintegration of the airframe as the aircraft departed the runway, the hydraulic systems would have been breached almost immediately, and with the loss if pressure, combined with the rapid deceleration of the aircraft, the T/R doors could have swung forward and shut, even if they had been deployed. Then again, perhaps they never were deployed in the first place. Hopefully the FDR will shed some light.

Flaps 10 or 20 are both authorized for takeoff, though I believe a flaps 20 takeoff is far more common. However, during the crew's preflight initialization of FMS performance data, on the Takeoff Init page 3, they have to enter which flap setting is going to be used. As far as I know, the default flap setting on this page is Flaps 20, and the crew would have to specifically hit the 3R line select key "OR 10" to tell the perf computer that a flaps 10 takeoff is planned.

If the FMS takeoff Init had been left at the default flaps 20, and the flaps had inadvertently only been deployed to 10 degrees, the v-speeds would not have "boxed", and there would have been a large yellow "VSPD" caution flag next to the airspeed tape on the pilot's PFD display. Checking that V-speeds are valid is a standard part of the crew's checklist prior to taking the runway, and I doubt that it could have been missed.

In other words, if they indeed started the takeoff roll with flaps 10, I have to think that it was their specific intention to use flaps 10, or they would have noticed the missing V-Speeds before ever advancing the power levers.

There is also a separate takeoff config alarm system, which is operated by microswitches which is activated when the power levers are advanced beyond a certain point. This will give a triple-chime master warning tone and light, as well as a red CAS message if the power levers are advanced and the flaps position sensors detect that the flaps are either less than 10, or greater than 20 degrees.

Now, I HAVE seen this system fail. I don't know if GIV crews routinely test the takeoff config system as part of their preflight cockpit flows, but there is a maintenance requirement to do a functional test of the system every 12 months. We had an early-model (1989) GIV, and when I performed the test in the hangar when it came due, lo and behold, there were no warnings, even with both PLs fully advanced, and the flaps fully up.

It turned out that the microswitches on both the left and right power lever sectors had failed - probably due to age. I remember it particularly well, as accessing and changing the switches was an absolute b***h of a job, due to their location.

I would not want to speculate as to what might have happened in this accident, other than the obvious fact the aircraft departed the end if the runway at high speed without becoming airborne. I do hope that the CVR and FDR will have recoverable data, that will shed light on what may have happened, as this kind of tragedy is shocking to all of us who maintain and fly the GIV.

glendalegoon

3rd Jun 2014, 02:12

Astra driver

3rd Jun 2014, 02:42

glendalegoon

3rd Jun 2014, 02:54

I haven't seen the pictures, so sorry.

Am I to understand the thrust reversers were NOT deployed?

I speculated earlier, referring to an aborted takeoff with a lear, in which due to mx malfunction, the plane, "THOUGHT" it was in the air and could not use reversers or max wheel braking.

any ideas of similar wow/squat switch logic here?

also wondering on condition of tires, could nose wheel have blown and sucked into eng?

ThreeThreeMike

3rd Jun 2014, 03:20

also wondering on condition of tires, could nose wheel have blown and sucked into eng?

If you look at the photo in post #35 the nose gear was torn off when the aircraft left the runway and the tires are still intact.

Also noticeable is that anti-skid was operational.

glendalegoon

3rd Jun 2014, 03:23

three three mike

thanks

I guess what I am saying is maybe the plane thought it was in the air and the anti skid didn't work, and then the plane thought it was on the ground and then it did start working.

if the tires are intact, we can assume they were not sucked into engine. but maybe something else like owls were.

JRBarrett

3rd Jun 2014, 03:44

JRBarrett thanks for the great info do you know if there is a control lock that might not have been disengaged? wondering also if ther emight have been a major airspeed indicator failure (mind you, we are taught to rotate regardless of airspeed in the last 1ooo' of runway in certain circumstances)

Yes, there is a control lock - it is a red lever on the center console that is engaged by pulling it up to a latched position. It will lock the ailerons, elevators and rudder.

While the lock is fine for preventing the control surfaces from moving in gusty winds, it is not all THAT durable. The locking mechanisms could be easily overpowered (which is to say broken) by the power available to the control surface actuators once hydraulics come online.

For that reason, releasing the control lock is called out in the BEFORE starting engines checklist, as breaking the locks is a definite possibility once hydraulic pressure builds up, if an attempt is made to to move to move the yoke.

There is also a checklist requirement to test the stall barrier (stall warning) system before flight, after engine start. This entails pulling the yoke full aft, while the PIC and SIC, simultaneously press test switches, (each on their own side of the cockpit) for several seconds. This tests the AOA sensors, the stick shaker, and (lastly) the hydraulic stick pusher. Again, it would be impossible to perform this op test with the control lock engaged.

The ailerons and elevators are mechanically controlled via standard cables, pulleys, sectors etc. Ordinarily, the cables also control the hydraulic boost actuators at the control surfaces, but even in the case of a dual hydraulic failure, the controls would go to full mechanical reversion, meaning the surfaces can still be moved solely by pilot "muscle power" - Although it would be like manhandling a Mack truck without power steering, it would not be like losing all hydraulics in a purely FBW aircraft.

The GIV is not particularly "touchy" about elevator trim either. Some aircraft require the trim to be set to within a degree (or less) of a pre calculated value before takeoff, based on current CG. On the GIV, setting the trim to "somewhere in the general vicinity" of 10 degrees is usually perfectly fine. Which is to say that the "green band" on the trim wheel is quite wide.

Horizontal Stabilizer trim is a different matter though. The entire H-Stab moves progressively leading-edge down, automatically as the flaps are deployed. On the GIV this is accomplished by a rotating torque tube, running up the inside of the vertical stab, that is driven by the same hydraulic motor that drives the flap jack screws.

On later-model Gulfstreams, the H-Stab is driven by its own actuator, which is independent of the flap drive actuator.

Not being a GIV pilot, I am not sure what effect on pitch authority would result, if for some reason, the Horzontal Stab did not move to the proper position for the selected flap setting. I can think of several ways such a failure could occur from a mechanical perspective. The flap position indicator on the flight deck is a dual gauge, which shows both flap and H-Stab position, but am not 100 percent sure if an H-Stab not set properly would generate any other config warning (I.e. CAS message etc.) on the GIV. I'll have to check my maintenance manuals tomorrow.

glendalegoon

3rd Jun 2014, 04:14

JRBarrett

3rd Jun 2014, 04:43

JRB thanks for your expertise. I just want to understand for sure that this type has both ELEVATOR trim (tabs) and moving stabilizer? interesting. I understand about the movement to counter flap pitch change. just interesting!

Correct. The horizontal stab physically moves as the flaps extend to counteract the change in pitch induced by the flaps - and the two (flaps and hstab) are mechanically interlinked. The horizontal stab basically has 4 fixed positions for flaps up, flaps 10, flaps 20 and flaps 39. (though it does move continuously between these fixed positions as the flaps run in or out).

Once the flaps are fully retracted, the H-Stab moves back to its "normal" position, and remains fixed there, with normal trim authority coming exclusively from the elevator trim tabs.

This is different than other T-Tail biz jets, eg: the Beech 400A, where a moving H-Stab (electrically actuated) is the primary source of manual and autopilot trim - likewise for most Lears.

JRBarrett

3rd Jun 2014, 05:51

In an earlier post I had hypothesized that this was not an overrun accident, but the presence of tire skid marks running through and off the end of the 1,000ft overrun area would seem to indicate it is just that. What is still baffling to me is that if this is an aborted take-off overrun, why did they not deploy their thrust reversers? I can only say that from having to perform a near V1 abort myself (due to multiple bird strikes) I was practically bending the T/R levers backwards along with pressing the brake pedals to the firewall when I saw the end of the runway coming up. The setting of Flaps 10 is equally puzzling to me from this airport, all Gulfstream jets use Flaps 20 as an almost default take-off setting except when taking off from high density altitude airports with long runways, where second segment OEI climb gradient becomes a greater performance limititation than BFL. That being said, I am aware of some crews preferring to use Flaps 10 as well as a minimum "Flex" (reduced power setting) in order to give their passengers a smoother take-off and less steep initial climb out angle. If this was the case it would likely increase the BFL from well under 4,000ft (Flaps 20, min EPR) by about an additional 2,000ft to just under 6,000ft, but still not enough to explain on overrun of 2,000ft beyond a 7,011 ft runway.

A few years ago, I spent a couple of months riding in the jumpseat of a GIV, being operated in Africa. Due to the lack of mx services at many of the airports, the aicraft owner wanted a mechanic onboard for all trips.

The only time I ever saw flaps 10 used for takeoff (as opposed to 20) was the very scenario you describe. Departing heavy from Abuja, Nigeria, on a day that was close to 40C. The crew had a long preflight discussion about second segment climb performance - most of which went over my head - but the decision to do a flaps 10 departure was determined to be the only safe option. I do recall that ground roll and v-speeds were quite a bit higher than what I was used to seeing.

Still, I'm no expert as to the operational/piloting aspects of the GIV, other than knowing that it would be difficult to accidentally takeoff with flaps 10 (when 20 was intended) due to the conflict between actual flap position and FMS takeoff init, which would prevent v-speeds from displaying if the two did not correspond.

Hard to say about the thrust reversers based on the photo. Both T/R and ground spoiler deployment require positive weight-on-wheels, but as I mentioned in another post, the T/R "buckets" are held open solely by hydraulic pressure via their actuators - there is no locking mechanism to hold them open. If hydraulics were instantaneously lost due to the ongoing disintegration of the fuselage as the overrun progressed, combined with rapid deceleration of the airframe, I can envision a scenario when the T/R doors POSSIBLY could have been thrown forward and (mostly or completely) closed from inertia.

One of the news reports on Sunday, quoted a woman who lived near the airport who said that the engines were "really screaming" just before the sound of the crash and breakup. Cound have been a last ditch attempt to firewall the engines to get airborne, but based on the skid marks, equally likely to have been the sound of an attempt to apply max reverse thrust.

Hopefully the FDR and CVR will shed some light.

DownIn3Green

3rd Jun 2014, 09:50

Glitchy,

Once it becomes public knowledge, it is in my opinion OK to post the names...

More thought provoking is the photo above your post, showing the skid marks and overrun....

Many of us have or almost have been there, but knowint this view was one of the last views that flight crew would ever see is definitely eerie....:sad:

ramble on

3rd Jun 2014, 10:40

It looks like they tried to go after they left the runway.

The runway skid marks show that the tyres were intact and braking when they left the runway so its not a main gear tyre failure.

But there is no other obvious drag device deployment - the TRs look like they are still stowed and the Ground Spoilers dont look deployed.

The main gear furrows after the runway end stop almost coincidentally with the loss of the nose gear as if the braking stopped (lost the hydraulics?).
After that point (with no brakes) there are obvious brown singe marks from both engines (both producing thrust) on the grass from high thrust at a high nose angle just before it hit the approach light berm.
Fire then started from that point.

In an abort in the GIV, if the throttles arent pulled to a point very close to the idle stops then Ground Spoilers arent available and Reverse Thrust requires the throttles to be at the idle stops. If they arent back then residual forward thrust will not be helping the attempt to stop either.

What a terrible little gulley to have just off the end of the runway - a survivable and slow impact here probably caused the breakup and fire.

Were the crew experienced GIV guys?

glendalegoon

3rd Jun 2014, 13:20

here is a diagram of the runway. note the over runs on both ends.

http://155.178.201.160/d-tpp/1406/00626AD.PDF

a thought struck me that perhaps the pilots took off from an intersection by mistake and didn't have sufficient runway for takeoff.

just a thought mind you.

doesn't it remind you a bit of the lexington, kentucky crash of the RJ, taking off on the wrong runway

jfill

3rd Jun 2014, 14:55

From the photos, it looks like the boarding stairs were deployed. I wonder it there was an evacuation attempt or did rescue personnel open the door?

JimL1

3rd Jun 2014, 15:07

Some tragic pics:

Wreckage of private jet that killed Lewis Katz and 6 others revealed | Mail Online (http://www.dailymail.co.uk/news/article-2646565/Charred-wreckage-private-jet-claimed-lives-billionaire-Lewis-Katz-six-revealed-emerges-pilots-didnt-time-issue-call-help.html)

maxred

3rd Jun 2014, 15:48

A fairly comprehensive set of photographs

Photos: Crash at Hanscom (Photo 1 of 31) - Pictures - The Boston Globe (http://www.bostonglobe.com/metro/2014/06/01/photos-crash-hanscom/7ZKLQoCcwH9aW105KEZFgP/story.html?pic=1)

Astra driver

3rd Jun 2014, 20:50

Jfill,

Judging from all the smoke and soot on the stairway of the air stair I would say that it was likely opened in an evacuation attempt. It is also possible that the impact with berm caused the door to come open like that.

Another thought I had is that perhaps the door came unlatched during the take-off roll and it was the "Door Unsafe" CAS message that triggered the abort.

It's impossible to tell from the photos whether or not the Ground Spoilers deployed, but as Mr Barrett points out if they were not not armed, the crew would not be able to get their speeds to "box" along with a blue CAS "Ground Spoiler Unarmed" CAS msg when they took the runway. It is permissible to dispatch any Gulfstream with the Ground Spoilers disabled, however it requires the use of Flaps 20 and Anti Skid functioning on a non-contaminated runway to do so. In this case the Flaps were supposedly set at 10, so that would seem to remove that possibility.

About the only thing I can deduce from the accident photos is that the elevator Trim appears to be correctly set nose up and the Thrust Reversers were not deployed, which makes me wonder if the crew pulled on the piggyback levers to command them but for some reason the buckets failed to deploy and they got forward thrust instead. I recall a Lear accident a few years ago where a tire blew on the take-off roll and pieces of the tire disabled the W.O.W. System preventing deployment of the T/R's, the aircraft subsequently went off the end of the runway at considerable speed because they thought they were commanding reverse thrust when in fact they were getting forward thrust.

robbreid

3rd Jun 2014, 21:14

Little more info - CVR and FDR recorded everything.

Doesn't confirm where on the runway the run started but is sounds like threshold.

Normal takeoff - call out 80 knots, V1, Rotate, aircraft did not rotate - not being specific what
was said, but pilots confirmed loss of control - speed at 165 knots.

Thrust reversers deployed, heavy braking - 7 seconds later - last recorded speed 100 knots

from start of take off to end of cvr tape 49 seconds.

No wildlife reported.

glendalegoon

3rd Jun 2014, 22:31

astra

yes, I mentioned that lear/ wow thing earlier.

how wouldyou like to get to V1R and pull back and NOTHING HAPPENS?

amazing synopsis of the cvr. thanks robbreid.

sounds like flight controls are suspect, or at least W&B questions. Remember that Challenger that had a forward C/G and couldn't rotate ? everyone survived that one.

satpak77

3rd Jun 2014, 22:39

FrankR

3rd Jun 2014, 22:49

A word of caution is in order:

Much has been said here. Most of the systems information and references are correct, a few are a little off, but substantially correct.

However, the conjecture being put forth is premature, and I would hope that people posting would make sure that they are posing a question, not putting forth fact...

FrankR

3rd Jun 2014, 22:53

This latest news article talks about the 49 second recording

UPDATED: Flight records capture the 49 secs of the plane's movement - News - Lexington Minuteman - Lexington, MA (http://lexington.wickedlocal.com/article/20140602/NEWS/140609446)

Brian Abraham

4th Jun 2014, 01:19

From an email I received from Aviation International News (public release)NTSB investigators located the cockpit voice and flight data recorders last night from the Gulfstream IV-SP that crashed at about 9:40 p.m. on Saturday while taking off from Runway 11 at Bedford Hanscom Field near Boston under FAR Part 91 operating rules. All seven aboard were killed, including passengers Lewis Katz (co-owner of the Gulfstream), Anne Leeds, Marcella Dalsey and Susan Asbell, and the three crewmembers–chief pilot James McDowell, copilot Bauke “Mike” de Vries and flight attendant Teresa Benhoff. According to NTSB senior investigator Luke Schiada, the U.S.-registered GIV-SP–S/N 1399, manufactured in 2000 and registered as N121JM to SK Travel llc of Raleigh, N.C.–crashed into a ravine in a wooded area about 2,000 feet beyond the end of the runway along its extended centerline. An eyewitness told NTSB officials that the GIV-SP, which was departing for Atlantic City, N.J., never lifted off the ground. The aircraft was largely consumed in a post-crash fire. The 15-person accident investigation team–which includes personnel from the NTSB, FAA, Gulfstream, Rolls-Royce and the UK Air Accidents Investigation Branch–will remain on site until this evening. Investigators have secured the aircraft maintenance and crew training records and are now collecting airport surveillance videos. According to Schiada, the CVR and FDR will be analyzed at the NTSB lab in Washington, D.C. He also said that McDowell had 18,500 flight hours and de Vries had 11,200 flight hours, and that the aircraft had logged 4,950 hours since new.

glendalegoon

4th Jun 2014, 01:34

jrrbarret

i can imagine that if the stab trim did not command nose up<with flap position> ( leading edge down) that it would be difficult to rotate. wondering if it has ever failed?

FrankR

4th Jun 2014, 04:21

... it has NOT

We should all wait for details to be reported.

Many of the "what if" scenarios presented here are completely with out merit.

glendalegoon

4th Jun 2014, 05:08

FrankR

theories were proposed early on as information was slow in coming. modifications as additional information released.

things can fail Frank. just about anything can.

we are just talking here like we might in the hangar

Feathered

4th Jun 2014, 05:16

a thought struck me that perhaps the pilots took off from an intersection by mistake and didn't have sufficient runway for takeoff.

just a thought mind you.

doesn't it remind you a bit of the lexington, kentucky crash of the RJ, taking off on the wrong runway

I know this airport well and seriously doubt that there was an intersection take off attempted for a number of reasons.

The preferred runway is 29, assuming no wind factor. The winds that night were light to nill. Although Hanscom can get crazy busy during the weekday, after dark on a Saturday night, the airfield was probably near deserted by comparison, with just a few operations per hour. A taxi to Runway 11 is very short, since the runway starts very close to either FBO. That saves a mile and half of taxi and is likely the reason for the Rwy 11 departure. It would be interesting to hear the ATIS at the time of the accident.

There are no realistic intersection spots for a 11 departure, even for a smaller plane--the available runway at either G or F is not great for a jet. It also wouldn't make sense (even starting from runway 5-23), since you'd be taxiing parallel to a long runway and THEN taking off on the rest of it. The jet was almost certainly parked at an FBO (Jet or Signature), not on the east ramp which is adjacent to the USAF base and has limited easy access for civilians.

If the G IV had departed on Rwy 29 and had the same scenario on the runway, the outcome might have been different, as there is no downgrade and river after the runway overrun ends in that direction. But there are also trees after a long cleared area so who knows.

Astra driver

4th Jun 2014, 06:53

Can no longer find the link to the Metar at the time of the accident, but basically it was winds calm and good visibility. A departure using the full length available from Runway 11 most likely offered the shortest taxi from either FBO.

tempilot

4th Jun 2014, 08:56

Can anyone answer this: How long did it take for the crash/fire/rescue services to reach the scene of the accident?
Tempilot

Feathered

4th Jun 2014, 15:14

From what I understand, fire crews arrived less than 3 minutes from the accident. They were notified immediately by the tower. The USAF provides fire and rescue on the field. Also responding were fire crews from the neighboring towns of Lexington, Bedford, and Burlington who were there shortly thereafter. An environmental team from the Bedford FD had booms in the river downstream for the crash within minutes while the firefighting crews fought the fire.

fantycloud

4th Jun 2014, 15:28

compare news coverage to this accident vs the aspen crash.... Is it a coincidence that it was a newspaper boss that perished? I want to know about the accident and the news sites are sush.... guess we wait for NTSB report.

robbreid

4th Jun 2014, 16:09

Info from Luke Schiada - Senior NTSB Investigator in charge of N121JM investigation.

tempilot

4th Jun 2014, 16:17

Thanks Feathered and Robbreid. T.

satpak77

4th Jun 2014, 16:20

According to this, crew called "rotate" and after that point, control issues possibly came into play. Simplistically, I wonder if after rotation, the aircraft failed to rotate (for whatever reason)

Plane?s brake pressure rose before Hanscom crash, data show - Metro - The Boston Globe (http://www.bostonglobe.com/metro/2014/06/03/hanscom-crash-briefing-expected/vDWlq9UV9RhwOpuA0qUIvM/story.html)

BEDFORD — The Gulfstream IV jet that crashed at Hanscom Field Saturday night, killing seven people, reached a speed of 190 miles per hour before slowing down during its attempted takeoff and hurtling into a gully, air crash investigators said Tuesday.

Information from the plane’s flight data recorder indicated that the jet’s thrust reversers had been turned on and that brake pressures were rising, Luke Schiada, the lead investigator for the National Transportation Safety Board, said at the scene.

The scenario described by the investigator suggested that the pilots were trying to abort the takeoff, one veteran pilot said. Thrust reversers are typically used to slow planes down by diverting jet exhaust to the front, rather than the back, as in normal operation.
Related
Photos
6/01/2014 - Bedford, MA - Hanscom Air Force Base Civil Air terminal - Frank McGinn, cq right, with the Massachusetts State Police, and Gary Coffey, cq, left, with the FBI, were on site at Hanscom Air Force Base the morning after a fatal plane crash that killed 7 people, including the co-owner of the Philadelphia Enquirer. Members of the media waited on Sunday morning for updates regarding a fatal plane crash at Hanscom Air Force Base that took place on the night before on May 31, 2014. Dina Rudick/Globe Staff.
Photos: Crash at Hanscom

Data, voice recorders recovered
Video: Hanscom jet crash
Audio: 911 calls after the crash

“The thrust reversers deployed and the wheel brake pressures rose as the airplane decelerated,” Schiada said. “We’re also observing tire marks on the runway.”

Schiada declined to say outright that the pilots were trying to stop the plane, saying: “We’re not interpreting the information that the thrust reversers were deployed. . . . I don’t want to interpret what the actions are.”

He also did not give any indication as to why the crew might have been trying to stop the plane.

“We’re not going to speculate,” Schiada said.

However, Bruce Landsberg, an experienced pilot and president of the Aircraft Owners and Pilots Association Foundation in Frederick, Md., said it sounded as though the pilots had decided to halt the plane.

It appeared, he said, that “the crew, for whatever reason, decided they needed to reject the takeoff, and they ran out of runway before they got the airplane stopped.”

As it raced down the runway, the airplane reached a maximum speed of about 165 knots, or about 190 miles per hour, Schiada said. But the flight data recorder indicated it never left the ground.

The flight recording ends about seven seconds after the thrust reversers were deployed. At that point, the plane had slowed to about 100 knots, or 115 miles per hour, Schiada said.

In addition, the jet’s cockpit voice recorder captured various callouts in the cockpit, including “rotate,” as the plane sped down the runway. That is typically the signal from the copilot to the pilot to pull back on the control yoke and bring the nose up, Landsberg said.

“After the rotate callout, the [cockpit voice recorder] captured comments concerning aircraft control,” Schiada said.

The NTSB investigator would not elaborate on what those comments were.

Schiada said the cockpit voice recording ultimately ended with the sound of impact.

On Monday, investigators recovered the two recorders. Schiada stressed that the analysis of the data from the recorders was preliminary “and we still have a great deal of work to do.”

He said both devices had captured hours of data, including the final 49 seconds of the flight when the plane began to roll down the runway and then crashed.

According to Schiada, the cockpit voice recorder had captured about two hours of “good to excellent” audio, while the flight data recorder had captured about 41 hours of data. Both devices were made by L-3 Communications.

The plane was taking off at about 9:40 p.m. Saturday, heading to Atlantic City, N.J., with Lewis Katz, 72, co-owner of the Philadelphia Inquirer, aboard, as well as three of his guests and a three-member crew.

NTSB officials have said the plane left the end of the official runway, which is 7,011 feet long, traveled another 1,000 feet over extra paved surface, and then another 819 feet on the grass before hurtling into a gully at the edge of the airport, where it was consumed by flames.

Along the way, the Gulfstream IV destroyed an antenna used to guide planes on instrument landing approaches, as well as a chain-link fence, investigators have said.

The crew members aboard the plane were: pilot James McDowell, 51, of Georgetown, Del.; copilot Bauke “Mike” De Vries, 45, of Marlton, N.J.; and flight attendant Teresa Ann Benhoff, 48, of Easton, Md.

Katz’s guests were Anne Leeds, a retired preschool teacher from Longport, N.J.; Marcella Dalsey, executive director of the Drew A. Katz Foundation; and Susan K. Asbell, who served with Dalsey on the strategic planning committee of the Boys & Girls Club of Camden County, N.J.

Investigators expect to remain at the crash site gathering information through the end of the week, Schiada said. A preliminary report on the crash is expected to be issued by the agency next week.

In the meantime, Schiada said, investigators will continue reviewing information about the flight crew, witness statements, and surveillance footage, among other evidence. The recorders have been forwarded to NTSB labs in Washington, D.C.

Schiada said that investigators had not found any problems with the plane’s brakes or tires and that authorities were also reviewing the configuration of the flaps at takeoff.

Investigators have not had a chance to examine the engines yet, he said.

Bruce “Buck” Rodger, president of the Los Angeles-based Aero Consulting Experts, said a number of factors may have contributed to the crash.

“There’s always a buildup to a reason why an airplane has crashed,” Rodger said. “There will be more than one event here, absolutely.”

robbreid

5th Jun 2014, 00:01

They stated the FDR indicated the thrust reversers has deployed 7 seconds before the cvr stopped recording - the impact sound was heard - just a note that the wreckage shows the reversers stowed ?

Jet Jockey A4

5th Jun 2014, 11:30

"compare news coverage to this accident vs the aspen crash.... Is it a coincidence that it was a newspaper boss that perished? I want to know about the accident and the news sites are sush.... guess we wait for NTSB report."

I believe the fact that other jets waiting for takeoff in Aspen saw the accident live and indeed took pictures and videos as it happened help the Aspen crash make more news.

Also there were IIRC 4 airport camera videos published showing the whole crash as it happened.

Jet Jockey A4

5th Jun 2014, 11:36

tlbrown350

5th Jun 2014, 14:23

Anyone familiar with the GIV before T/O control lock procedures.

Malfunctioning Flight-Control System Likely Led to Lewis Katz Jet Crash - WSJ (http://online.wsj.com/articles/malfunctioning-flight-control-system-likely-led-to-lewis-katz-jet-crash-1401870715)

JRBarrett

5th Jun 2014, 14:30

Too early to know what happened in this crash and I don't want to speculate but this accident reminds me of the Challenger 600 crash in Teterborro. Both very high speed rejects where the aircraft failed to get airborne because of some sort of issue. Of course now we know the reasons behind that Challenger crash, and wonder if something similar happened here. Could a G IV be loaded in such a way as to prevent a normal rotation at Vr?

I can't think of any operational load-out of a GIV that would produce a fwd CG so far out of limits that the aircraft would be unable to rotate. It is a completely different design than the Challenger 600, which

On a GIV, one would have to load many hundreds of pounds of cargo in the forward entrance corridor to move the fwd CG out of limits. Not something likely to be done in a high-end executive jet.

The fuel and pax load of the Challenger at TEB put them over gross, and out of CG limits.

The GIV has a max fuel capacity of 29,500 pounds. They probably had less than half of that for the short hop from BED to ACY, and with just 4 pax, it stands to reason that they were loaded well within the normal envelope.

I'm pretty sure that this accident was the result of some sort of major failure in the flight control system - but I will leave it to the on-scene NTSB and manufacturer's investigators to determine the exact nature of the failure. Because of the massive destruction of the airframe from the impact and fire, that investigation may take quite some time.

Feathered

5th Jun 2014, 15:19

What kind of flight control systems check would be on the preflight checklist? Are the flight controls even visible from the G IV cockpit?

znightflyer

5th Jun 2014, 17:27

Anybody have a link to the series of picture that were posted...seems the link is not valid anymore

mutt

5th Jun 2014, 17:42

What kind of flight control systems check would be on the preflight checklist?

Release the control lock prior to start.
Check Stall Barrier after start
Check ground spoilers
Check flight controls, wings can be seen using window mounted mirrors.

Bill Harris

5th Jun 2014, 18:22

Anybody have a link to the series of picture that were posted...seems the link is not valid anymore

It's still good:

Photos: Crash at Hanscom (Photo 1 of 37) - Pictures - The Boston Globe (http://www.bostonglobe.com/metro/2014/06/01/photos-crash-hanscom/7ZKLQoCcwH9aW105KEZFgP/story.html?pic=1)

and they seem to have revised the photos (different # of photos).

Astra driver

5th Jun 2014, 18:23

The GIV like all other Gulfstream models is very easy to keep within CG limits, a Pax load of 4 would almost certainly be within CG limits regardless of where they sat within the cabin, and so long as one starts within the CG envelope it is impossible to take on a fuel load that would shift you outside of it.

As far as control checks go, in recent years a "Bungee check" of the elevator controls was added to the line-up checklist for legacy Gulfstream models (G2 through G5) which involves pulling the control column full aft and then releasing to ensure it falls full forward with no bounce. Not sure if all crews are complying with this though.

susier

5th Jun 2014, 18:38

Pardon me if this is a(nother) silly question, but what would be a possible cause of the landing gear separating from the a/c?

Is this likely just a result of heavy braking conditions and so on?

I mean, normally the gear fails (I think?) as a result of a heavy landing but it didn't take off/land on this occasion so I couldn't work out why it might have separated.

Thank you.

ETA: Apologies, I can see it could have detached as the plane went off the tarmac onto softer ground.

glendalegoon

5th Jun 2014, 18:41

JRBarret

I agree with your view. A very kind person PM'd me with an airworthiness directive which concerns the horizontal stab trim. Wondering if it was taken care of.

We shall see. I imagine the NTSB will have a reasonable answer quite soon.

It does offer the question: what do you do when you reach V1/Rotate and nothing happens? I've made my mind up on what to do. Especially when there is serious question of stopping.

Astra driver

5th Jun 2014, 18:56

Glendale,
"It does offer the question: what do you do when you reach V1/Rotate and nothing happens? I've made my mind up on what to do. Especially when there is serious question of stopping."

Curious, what would that be? Seems like your options would be few.

glendalegoon

5th Jun 2014, 21:47

hello astra driver

I want you to understand this is in the most desperate of conditions. That there is no hope with any conventional, trained or other thing we might have tried in a simulator or in real life.

I want you to understand that this is not a sure thing or advice for anyone who has any other options.

It presumes that the engines are running. But that some control problem has happened after V1 with no hope of stopping and the runway ends with a cliff or in the depths of the ocean or something horrific.

I would go to full flaps and firewall power an in hopes of getting airborne in one way or another and that the flaps would somehow be more appropriate to any jammed stabilizer setting. And that this would somehow give me a moment to do something else. It seems that this type of plane has unusual trim with a moving stabilizer for flap changes and elevator tabs for conventional trimming. Something odd in transport planes that I have flown (737 among others).

You asked and I wanted to share it with you as you appear to be another professional pilot. I hope you will understand the preamble and that it would not be a normal or trained for emergency situation. AND THAT IT MIGHT NOT WORK AT ALL! ;-)

Astra driver

5th Jun 2014, 22:29

Glendale,

Thanks for sharing, I'm always interested in the techniques of others, not sure if going to full flaps in the situation you described would help or not due to the added drag, but when you are quickly running out of options what do you have to loose, as this accident and the Teterboro Challenger accident have demonstrated a late abort will result in a serious and possibly deadly overrun, although I am still highly suspicious that some other factor conspired against this unfortunate Gulfstream crew that prevented them from getting the aircraft stopped in time.

The Stab/Trim used on the legacy Gulfstreams while perhaps seeming unusual compared to other transport aircraft has proven to be highly dependable in over 40 years of use on the G2 through G5 models. The '650 now uses a fully trimable/adjustable stabilizer on its FBW system, time will tell if this proves to be as reliable.

znightflyer

5th Jun 2014, 23:01

There's no way going to full flaps will help get the aircraft airborne.

glendalegoon

5th Jun 2014, 23:05

astra. consider that the plane is above v1/r

consider full/firewall power

i think it would get airborne, though curing the problem might be difficult thereafter. perhaps you are also thinking of the ''hail mary'' move that ernest k. gann made near the taj mahal.

znightflyer you may be wrong.

all the go arounds Ihave made have started with full flaps/landing flaps and they worked out fine.

H Peacock

5th Jun 2014, 23:28

"It does offer the question: what do you do when you reach V1/rotate and nothing happens? I've made my mind up on what to do. Especially when there is a serious question of stopping"

Surely you abort. If the aircraft doesn't rotate when you ask it to then: idle, max reverse then start braking. May even then call for maximum flap to add a tad more drag. You may be a bit over V1, but you're only going to trickle off the end of the runway. Moreover, if your perf is biased for a balanced field or doesn't take any account of actual runway length you may well be able to safely stop on the runway despite initiating the abort well above V1.

Undoubtedly when V1 = Vr then it is a no-brainer. You may be unlucky and bend the gear if you cross a gulley, but if you try to fly in an aeroplane that just doesn't want to fly then the outcome will be inevitable.

Not an everyday scenario, but I don't subscribe to never aborting above V1.

This is simply my response to the question above about a specific problem, not the reason these poor souls perished.

glendalegoon

5th Jun 2014, 23:31

peacock

I made some very specific conditions including that going off the end would end in disaster (cliff)

if the situation would allow for an abort, fine. but it sure didn't work in Bedford.

FrankR

6th Jun 2014, 04:10

Almost imposable to be out of CG, and same for having control lock. It's a guarentee that these were not the issue.

CL300

6th Jun 2014, 05:03

What always bugs me, is the fact that virtually no-airport is using EMAS at all ! Some do of course, but this should be kind of a requirement, instead of the loss of lives and a write off; if would be an inspection and a replacement of the affected blocks ( especially at airports where the perimeter ends with a ditch/cliff/motorway/warehouse,etc.)
If the industry is learning from this one ( it did not from the Challenger in TEB, or AA, AF, ); EMAS would come as more standard than anything else on a runway construction plan, no ?

fantycloud

6th Jun 2014, 05:14

but its david katz.... maybe they didnt like him as much as dick evertal

FrankR

6th Jun 2014, 05:41

HI CL300,

Do you think that EMAS would help at 160 Kts?

I'm no expert, but it seems that this wouldn't have helped here.

Please cite examples of arresting accelerating aircraft if you have some, I always thought it was only for low-speed excursions.

FR

CL300

6th Jun 2014, 06:50

The flight recording ends about seven seconds after the thrust reversers were deployed. At that point, the plane had slowed to about 100 knots, or 115 miles per hour, Schiada said.

I am not selling EMAS but : Fact Sheet ? Engineered Material Arresting System (EMAS) (http://www.faa.gov/news/fact_sheets/news_story.cfm?newsId=13754)

this is 243 people alive, and therefore limited headlines in newspapers...a bit like engines inflight shutdowns...barely leaving the quality report database...

susier

6th Jun 2014, 07:05

EMAS Save at ORD [Archive] - PPRuNe Forums (http://www.pprune.org/archive/index.php/t-335783.html)

This discusses the incident from that link with the most passengers/crew on board, (Mexicana 2008 at ORD) but I can't find any reference to how fast the plane was going at the time.

Any idea what the limitations are in regard to speed? The EMAS factsheet link doesn't seem to indicate that.

Thank you.

CL300

6th Jun 2014, 08:17

it says that to date the fastest was 80kt, but there is no limitation as per se..AFAIK

znightflyer

6th Jun 2014, 12:10

Cl300

It's all about $$. The FAA started requiring airports to have runway areas and if there wasn't enough room then EMAS was an option.

EMAS are great when there is not any runway safety areas (RSAs) The RSA is typically 500 feet wide and extends 1,000 feet beyond each end of the runway. Bedford meets the RSA standards. It provides a graded area in the event that an aircraft overruns, undershoots, or veers off the side of the runway. Many airports were built before the current 1,000-foot RSA standard was adopted approximately 20 years ago. They would have most likely gone through the EMAS too.

Something strange happened to this flight for sure.

Old Boeing Driver

6th Jun 2014, 12:45

The control lock is supposed to lock control surfaces, and prevent advancement of the thrust levers.

I've flown most of the Gulfstream jet models, and they all worked this way.

A Gulfstream maintenance guru friend says that it may be possible that the pin preventing thrust lever advancement was either out of rig, or broken, thereby allowing the control surfaces to be locked, but allowing thrust levers to be advanced (to takeoff power).

However, this was a very experienced crew (in that model), and I would hesitate to say they did not do a flight control check, which is on the checklist.

I'm also curious as to why they were using flaps 10 for takeoff there, and since reverse thrust was selected, why were the buckets closed in all the pictures.

znightflyer

6th Jun 2014, 13:31

Glendalegoon,

Understand and agree, you started with full flaps and retracted them to something less. You were in flight and probably called for TOGA/Flapsxx pushing power to max while retracting flaps to decrease drag, waiting for positive rate then gear up....

A GIV isn't a c150 where you can pop it off the ground by adding flaps. If they had flap 10 selected, and we're going 165 kts, selecting 20 or something greater would not have helped as there wasn't enough time for flaps to move with the remaining runway left.

GIV Rejected Takeoff procedure:

06-02-20: Rejected Takeoff 1. General:

Because of the diversity of Gulfstream operators, the decision as to who may direct call for a rejected takeoff is left to the individual operators. Once the decision is made to reject a takeoff, proceed as follows:

2. Procedure:

(See Figure 3.)

A. Pilot Flying (PF):

(1) Retard power levers to idle and apply maximum braking.

(2) Deploy speed brakes.

(3) Use reverse thrust if desired.

CAUTION

IF DIRECTIONAL CONTROL BECOMES DIFFICULT WHILE IN REVERSE THRUST, REDUCE THRUST TO REVERSE IDLE (OR FORWARD IDLE THRUST, IF REQUIRED). REGAIN DIRECTIONAL CONTROL, AND REAPPLY REVERSE THRUSTAS NECESSARY.

B. Pilot Not Flying (PNF):

(1) Verify ground spoiler deployment. If not deployed, PNF confirms PF has manually deployed speed brakes.

(2) Monitor engine instruments.

(3) Apply slight forward pressure on the control column.

(4) Notify tower of rejected takeoff as soon as conditions permit.

(5) When clear of runway, perform appropriate Emergency, Abnormal or Normal checklist, to include evacuating the aircraft, if desired.

NOTE:

After a rejected takeoff, the cabin pressurization system may still be in the FLIGHT mode of operation. Select the LANDING mode to allow the aircraft to depressurize.

(6) Check brake temperatures.

The NTSB mention there was a comment about a control issue. In all my years of training with jammed controls, I never had a session where at V1 I had a jammed elevator.

Again from the GIV manual:

Manual reversion of the pitch flight control system is also possible by closing a normally open flight power shutoff valve. The flight power shutoff valve is a mechanically operated shutoff valve located between the Combined and Flight hydraulic system pressure sources and the elevator actuator (as well as the aileron, rudder and flight / ground spoiler actuator) pressure lines. The valve consists of two mechanically connected but hydraulically isolated sections. A controlex cable connects the valve to a FLIGHT POWER SHUT OFF handle located on the left aft side of the cockpit center pedestal. See Figure 8.

Moving the FLIGHT POWER SHUT OFF handle up from its stowed (horizontal) position to the vertical position mechanically closes the flight power shutoff valve. With the valve closed, operating pressure is removed from the actuator, allowing the piston to idle.

The resultant advantage of the flight power shutoff provision is the ability to bypass a malfunctioning actuator (such as would be the need in the unlikely event of an actuator jam) and manually fly the aircraft. Although control column effort and response time to inputs are increased while in manual reversion, the aircraft remains capable of positive and harmonious.

4-15-30: Immovable Flight Controls:

DO NOT Pull Flight Power Shutoff Handle unless coupled with single engine emergency Rudder Control (Yaw) 1

PULL Flight Power Shutoff Handle Aileron Control (Roll) 2

PULL Flight Power Shutoff Handle Elevator Control (Pitch) 3

NOTE: Use only lateral and longitudinal trim after pulling Flight Power Shutoff Handle. Disengage Yaw Damper. Return directional trim to the neutral position prior to restoring h ydraulic boost to Ȁight control. If control is not regained in manual mode, return hydraulic boost to Ȁight controls. If Yaw Damper disengages as result of pulling Flight Power Shutoff Handle, do not attempt to reengage it until hydraulic pressure has been restored to Flight Controls....

Something else was happened.... There will be a chain link of events that happened that the NTSB hopefully will find. We all agree it wasn't a weather issue, nor an dangerous and challenging airport issue. The decision to use flap 10 is usually as it's normally used in high/hot second segment climb limiting issues; it does require more runway that selecting flaps 20.

601

6th Jun 2014, 14:31

One thing out of this accident is that the gully at the end of the runway needs filling.

mutt

6th Jun 2014, 14:50

why were the buckets closed in all the pictures. One possibility for this is that when the gear came off, the nutcracker system went into air mode, T/R's would then stow as they slowed down.

Astra driver

6th Jun 2014, 16:32

Quote:
why were the buckets closed in all the pictures.
One possibility for this is that when the gear came off, the nutcracker system went into air mode, T/R's would then stow as they slowed down.

mutt, I would agree with this scenario as well.

The consequences of this being that the engines would continue to now produce forward thrust, driving the aircraft on it's belly across the grass and into the gully.

Old Boeing Driver

6th Jun 2014, 17:54

That seems like a good possibility.

As a guess, it looks like they had a fair amount of forward thrust after going off the end and shearing the gear.

Old Boeing Driver

6th Jun 2014, 19:35

Just wondering. It's been a long time since my Gulfstream days.

If they were attempting full reverse thrust, and the nutcracker failed (due to gear being sheared, or otherwise), would the reverser's stow with the levers still up?

I seem to recall the G-III had a reverser restow switch, (In case of an inflight deployment), but I think the G-IV had a much improved system, which eliminated that switch.

I notice some skid marks in one of the pictures.

I wonder if the PF pulled the emergency brake handle, which has no anti-skid protection.

Thanks for any input.

mutt

6th Jun 2014, 20:48

would the reverser's stow with the levers still up? Yes, at around 60 Kts.

which eliminated that switch. Its still there.

I would go to full flapsThe initial increased lift may help you get airborne, but you would then get a nose down momentum that is totally opposite so what you need.

Old Boeing Driver

6th Jun 2014, 21:27

I found an old G-IV checklist and the "Thrust reverser emergency stow switch" is on the before start checklist.

I guess I was thinking about another model.

Thanks for your response.

Old Boeing Driver

6th Jun 2014, 21:44

Any idea why they would be doing a flaps 10 take off on a 7,000 foot runway at 8C and almost sea level?

A guess would be a 12,000 pound fuel load, and maybe a 1,000 pound payload for guessing at the T/O weight. Maybe 57-58,000 pounds at T/O

Thanks for your response.

TSchwarz

7th Jun 2014, 04:21

Quote:

would the reverser's stow with the levers still up?
Yes, at around 60 Kts.

Believe flight manual says IF flaps greater than 22 and BOTH wheels spin up to 65 kts. I think flaps were set at 10. Comments??

While I certainly do not know what happened, it seems logical that hand on reversers would be forced violently forward on deceleration from hitting ditch -- thus closing reversers.

Quote:

which eliminated that switch.
Its still there.

True -- functions slightly differently depending on serial number and ASC accomplishment. Also is pushbutton versus guarded switch on III.

Like all of you, I do not have definitive answers.

FrankR

7th Jun 2014, 04:41

It would be nice if someone had a GIV systems manual, but even then, there is a lot going on here, and we may easily miss something...

Regarding conditions you site for "TR" deployment, I believe you are thinking of conditions for ground spoilers, not TR's. TR's only have to be on the ground, at idle.

Reversers will NOT stow around 60 knots, you can ride them to your parking place, and shut down both engines with them out...

Regarding nose wheel WOW circuitry, I do not believe that this WOW information is used for TR logic, since I've seen plenty of pilots deploy the TRs with the nose wheel off the ground.

FrankR

7th Jun 2014, 04:58

Regarding flaps 10 takeoff.

A small minority of pilots (Incorrectly) assume that you get a gentler takeoff experience for passengers with flaps 10 takeoff... The entire Gulfstream family climbs like crazy, especially on liftoff. It is not unheard of to find crews exceed flap 10 speed due to this acceleration, especially when flying with minimum fuel.

Takeoff comfort aside, flap retraction is usually accomplished beginning at 400', and you are climbing at 3,000 FPM, so it begins about 10 seconds after takeoff.... Flaps 20 to flaps 10 takes 5-8 seconds, but flaps 10 to flaps up that takes 20+ seconds.

The tradeoff* is 4-5 Kt increase in V1 speed, 500 Ft increase in takeoff length, and a minor second segment climb performance numbers.

Oh, if you want a gentle climb out for your Pax, just do a flex EPR takeoff, and pull the power back when airborne...

*ballpark estimates

TSchwarz

7th Jun 2014, 06:18

"Regarding conditions you site for "TR" deployment, I believe you are thinking of conditions for ground spoilers, not TR's. TR's only have to be on the ground, at idle".

From the Flight Manual:
PROVIDING that the following conditions are met, 28V Essential DC Bus power is transmitted via the L TR CONT Circuit Breaker to the left TR arm indicator resulting in the TR ARM light on the pilot's instrument panel to illuminate:
-Left power switch (??) is in the idle position
- Left fire handle is in normal position
- T/REV EMER STOW switch is NOT depressed (and on airplanes SN 1000- 1143 excluding SN 1034 not having ASC 166 Nutcracker No. 3 relay
(on ground configuration) or on airplanes SN 1000-1143 excluding
SN 1034 having ASC 166 and airplanes SN 1034, 1144 and
subsequent.
- Either nutcracker No 3 relay energized (on ground) configuration or TR
wheel speed relay energized (wheel speed above 65 MPH (not knots)

With all the discussion about nutcracker failure or the aircraft being somehow in the air mode -- it appears we do not have enough data to intelligently speculate.

Frank R is correct. If the aircraft is in the ground mode, you can do a reverser check taxiing out -- apparently with either nutcracker #3 relay energized as long as in ground mode..

Confusion continues.

mutt

7th Jun 2014, 07:06

It would be nice if someone had a GIV systems manual, I do...

apparently with either nutcracker #3 relay energized as long as in ground mode.. We are only looking at reasons why the TR's are stowed, as the undercarriage came off the aircraft, we can assume that the nutcracker isn't working, therefore as per the AOM 2A-23-00

On the ground with Nutcracker failed in the air mode

Thrust reversers will stow at low speed
Ground spoilers will deploy with wheel spin up but will stow at low speed
Anti skid may not operate.
All braking may be inoperative at low speed unless anti skid is selected off
Engine idle set to 67% HP at low ground speed

IF we look at page 2A-78-00, it states
Either nutcracker #3 relay energised (On ground configuration) or TR wheel speed relay energised (wheel speed above 65 MPH)

So as you slow down and lose the wheel speed, you do not satisfy the requirements for TR deployment with the nutcracker in air mode and the TR's will stow. This is also the way that FSI are teaching the subject of landing with the nutcracker inoperative.

JRBarrett

7th Jun 2014, 12:59

The T/Rs are held in the open position solely by continuous application of hydraulic pressure from the onside hydraulic system through the T/R control valves mounted in the aft equipment bay. (The "boiler room" in Gulfstream parlance) -

The combined hydraulic system supplies pressure for left T/R, and the flight system supplies the right T/R.

As I mentioned in a previous post, if the T/R's are opened during maintenance by the use of an external hydraulic cart ("mule"), and the pressure from the cart is then reduced to zero, the T/R buckets can be pushed closed by hand with a bit of effort.

The combined system supplies the landing gear actuators, so the pressure and return sides would have been breached the moment the nose gear was torn off, and even more so when the mains departed.

Both flight and combined hydraulic systems would have been further breached by the contact of the wings with the localizer antenna, as both systems supply the aileron, flight and ground spoiler actuators through multiple lines on the rear beam of both wings.

Once the airframe started coming apart, I would think that any if the normal electrical and mechanical T/R control systems would have been rendered inoperative in any case, but with the loss of hydraulics, inertia could easily have slammed the T/Rs closed, as the aircraft slid though the terrain off the end of the runway and decelerated.

Not "proven fact", but it seems the most likely explanation to me.

FrankR

7th Jun 2014, 14:10

OK Mutt, if the nose gear shears, will you be in air or ground mode?...

Please check your manual for me, as my memory says that while the main nutcrackers are closed circuit in ground mode, the nose nutcracker is open in ground mode....

I think that the best place to focus is why did two very experienced pilots go from VR to VR+50 knots and stay on the ground...

CL300

7th Jun 2014, 14:28

@znightflyer
It's all about $$. The FAA started requiring airports to have runway areas and if there wasn't enough room then EMAS was an option.

EMAS are great when there is not any runway safety areas (RSAs) The RSA is typically 500 feet wide and extends 1,000 feet beyond each end of the runway. Bedford meets the RSA standards. It provides a graded area in the event that an aircraft overruns, undershoots, or veers off the side of the runway. Many airports were built before the current 1,000-foot RSA standard was adopted approximately 20 years ago. They would have most likely gone through the EMAS too.

This is well understood , and i am fully aware about airports designs and runways constructions, nether the less, we have another proven example where risk mitigation would have been in favor of the people inside the plane should a system of any kind been installed. ( and not a dip like here or in Toronto with AF overrun)

By the way ; skid marks on the pavement equals antiskid to the max or no antiskid ? i.e. no hydraulics ?

fantycloud

7th Jun 2014, 20:56

EMAS installed after the challenger runoff in TEB, and the southwest runoff in MDW (if im not wrong it wasnt there before).... so the EMAS folks are on the way to BED and some low politician will get credit for making BED safe.

The theory of nutcraker retraction is difficult to see because the preliminary reports indicate between 115-165kts at time of impact. so it never went down below 65kts. This was not a soft impact this was a high speed crash. Highly unlikely that trs would stow at impact, impact is impact, things dont have time to return to different positions at time of impact... This is the first thing NTSB looks at because its a tried and true system.

It sucks that the media doesnt cover this, such an important event. We just have to wait for NTSB details. With a big name like Katz I assumed that it would be nonstop coverage... but it wasn't.

I can't figure this one out, but I like reading everyones experiences and takes. Maybe flaps were not down and they tried to drop them while rolling down runway, or their trim was way off just inside t.o. trim. You can have an airplane within to trim and no horns and just a difficult time to pull aircraft off ground. Maybe they hesitated and tried to take off, aborting the abort?

Old Boeing Driver

7th Jun 2014, 21:44

I think you may be right with your statement that they possibly aborted the abort.

I still have a problem thinking the reverser's stowed themselves.

Just my thoughts.

Lucky8888

8th Jun 2014, 00:26

Doesn't the GIV auto-stow the reverse thrusters in the event of a hydraulic failure?

ThreeThreeMike

9th Jun 2014, 16:30

By the way ; skid marks on the pavement equals antiskid to the max or no antiskid ? i.e. no hydraulics ?

This photo indicates the anti-skid system was working. The tracks clearly exhibit darker and lighter deposition of rubber on the paved surface as the system modulated braking pressure.

http://bostonherald.com/sites/default/files/styles/full/public/media/2014/06/02/060214planemg011.jpg?c=512c6f66e845882d0a1bdc33b73a3baf

CL300

9th Jun 2014, 18:30

That simplifies the issue with hydraulics then no? Or G4 brakes are from only one hydraulic source ?

ThreeThreeMike

9th Jun 2014, 21:28

Block diagram of the GIV hydraulics:

https://farm4.staticflickr.com/3895/14199301469_a2b784d0ef_b.jpg

ramble on

10th Jun 2014, 06:38

The hydraulics lines were compromised at the loss of the NLG after the aircraft left the runway.

There would be no braking other than the Emergency Park Brake.

With a total fluid loss and no pressure to hold them open the TRs would be forced from the deployed position to the stowed position by the engine thrust on the deflectors.

chuks

10th Jun 2014, 09:25

Well, yes, but that's so late in the crash sequence, the loss of hydraulics, just after the aircraft has left the runway at something like 100 knots, that this will have made very little difference to the accident outcome. You can not get very good braking action off an unpaved surface, for one thing.

I think the focus will be on why the aircraft did not rotate at VR. What happened after that seems fairly obvious, finding out that you have an aircraft you can not make fly at 165 knots.

FrankR

10th Jun 2014, 11:35

I do not believe that they lost braking. The picture a few posts ago shows plenty of brake action. And the Combined hydraulic reservoir is large, around five and a half gallons if memory serves, and the engine pumps can easily overcome the escaping loss and provide pressure until the reservoir runs dry. The 550 has "fuses" that shut off fluid to the nose should this occur, but I don't know about the IV. If they had been using the emergency/parking brake, they would not have had anti-skid...

It took around 25 seconds to accelerate to V1 (around 115K), and the CVR ended at 49 seconds. They accelerated to 165 Knots yet didn't fly.... Understanding this tragic accident isn't a systems question, it's a "why" question.

zlin77

10th Jun 2014, 21:05

Autopilot engaged accidentally during the take-off run..? It has happened a few times on the B777, luckily no disasters occurred.

Astra driver

11th Jun 2014, 03:11

One thing that has been puzzling me is why there was a such a substantial over run at such a high speed, like many others I would think that there had to have been some other conspiring factor to cause such a large over run.

Out of curiosity I used the performance manuals for the G3 and G5 (No longer have any G4 manuals lying around) and came up with some rough numbers for stopping distances at approach speeds of 165 knots, these were typically in the region of 7,800 ft, at 500ft field elevation, unfactored, no wind. Subtract 1,000 ft from this to account for the 50ft threshold crossing height distance and an additional 1,400 ft credit for both thrust reversers operating and you get an approximate stopping distance on hard surface of 5,400ft.

Add to this the distance required to accelerate to 165 knots which I estimate to be at least 4,400ft (BFL's for flaps 10, field elevation 500ft, GTOW 60,000lb, come out to around this number)

Add these two numbers together, 4,400ft to go and 5,400 to stop and you get 9,800ft total.

Total distance from the start of the runway to the gully is approximately 8,900ft
(7,011 ft + 1,000ft overrun + ~890 ft to the gully)

Not saying that there weren't any other failures during the abort, just that a considerable overrun was a certainty with an abort started that far past V1 even with everything working perfectly.

finfly1

11th Jun 2014, 14:59

One of our aircraft (accidents) is (seemingly) missing.

N T S B - Aviation Accidents - Index of Months (http://www.ntsb.gov/aviationquery/month.aspx)

jdkirkk

11th Jun 2014, 19:31

I don't know the airplane, but are the gust locks physically outside and need to be removed?

http://www.smartcockpit.com/aircraft-ressources/Gulfstream_GIV-Flight_Controls.html

The Gulfstream IV primary flight controls system, shown in Figure 1, is a mechanically
actuated, hydraulically operated system that provides boosted surface control to
overcome the aerodynamic forces associated with high speed flight. This allows the
aircraft to be comfortably and reliably steered through the pitch, roll and yaw axes.
The primary flight control surfaces (elevators, ailerons and rudder) are positioned by
tandem type hydraulic actuators. The actuators receive hydraulic operating pressure
from both the Combined and Flight hydraulic systems, as shown in Figure 2. Both
hydraulic systems maintain a system pressure of 3000 psi. Loss of a single hydraulic
system has no effect on operation of the primary flight controls, as the remaining system
is capable of maintaining actuator load capacity. In the event of total loss of hydraulic
pressure in both hydraulic systems, the primary flight controls revert to manual operation.
Mechanical pitch, roll and yaw trim systems allow the flight crew to trim the aircraft. The
pitch trim system can also be controlled electrically by pitch trim switches on the control
wheels.
A gust lock secures the elevators, ailerons and rudder to prevent wind gust damage to
the surfaces.
Secondary flight controls, shown in Figure 1, include flaps, ground spoilers and
speedbrakes. These flight controls are hydraulically powered and electrically or
mechanically controlled. The mechanically operated horizontal stabilizer moves in
conjunction with the flaps to maintain longitudinal trim.
An Angle-of-Attack (AOA) system provides outputs to the control column shakers, control
column pusher, approach indexers, normalized AOA display and stall barrier system. The
control column shakers provides early warning of a stall scenario by vibrating the control
column before the stall while the control column pusher automatically initiates lowering
the nose if the stall is imminent.
The Gulfstream IV uses an aircraft configuration warning system to monitor landing gear,
flap, speed brake and power lever position. If an unsafe configuration is detected, the
system provides a visual and / or aural warning.
On CAA certified aircraft, a flight control automatic failure detection system compares
control inputs to actuator outputs. If a malfunction is detected, the system shuts off power
to the affected actuator.
The flight controls system is divided into the following subsystems:
• 2A-27-20: Pitch Flight Control System
• 2A-27-30: Yaw Flight Control System
• 2A-27-40: Roll Flight Control System
• 2A-27-50: Horizontal Stabilizer System
• 2A-27-60: Flaps System
• 2A-27-70: Spoiler System
• 2A-27-80: Gust Lock System

Astra driver

11th Jun 2014, 20:18

No, the gust lock is located on the throttle quadrant and should prevent the throttles from being advanced when it is engaged.

Obama57

11th Jun 2014, 21:58

The airplane could not rotate. The G-IV does not have HOPS or a way to disconnect/separate the elevator in the event of a jam. There is only one elevator actuator which is hydraulically powered by both (L/R) systems. All the ink about aborts and WOW switches seem to miss the point IMHO.

jdkirkk

11th Jun 2014, 23:14

Has runaway stab trim nose down on TO roll been mentioned?
Also, it seems they were – my guess - well above Vr when they rejected.
Since they must have been light, acceleration would have been rapid.
The tail area was pretty well wiped out but the jackscrew for the stabilizer should still be intact.

Astra driver

12th Jun 2014, 00:24

Obama,

Don't think anybody is missing the point here, we know from the CVR they had a "Control issue" and elected to abort. What that issue was is presently unknown and hence a source of conjecture.

Likewise the overrun, given the presumably light take-off weight of the aircraft and seemingly more than adequate runway length and overrun area which was almost double the required BFL naturally causes one to wonder if there was another failure that caused the overrun, although as I posted previously I now think the overrun was purely a result of the very late, high speed abort.

Old Boeing Driver

12th Jun 2014, 02:04

I think you may be correct in the idea the over run was from a very late, high speed abort.

As mentioned earlier, maybe an aborted-abort? They have a control issue, think they have it solved, but no they don't?

I know this was a very experienced crew, but something along those lines is probably going to show up when the CVR and FDR info is released.

SLFgeek

13th Jun 2014, 14:56

Preliminary report has been posted by the NTSB

Preliminary Report: Crash on takeoff of Gulfstream Aerospace Corporation G-IV, Bedford, MA, May 31, 2014 (http://www.ntsb.gov/investigations/summary/ERA14MA271_preliminary.html)

mutt

13th Jun 2014, 16:33

con-pilot

13th Jun 2014, 18:00

The FDR data revealed the elevator control surface position during the taxi and takeoff was consistent with its position if the gust lock was engaged. The gust lock handle, located on the right side of the control pedestal, was found in the forward (OFF) position, and the elevator gust lock latch was found not engaged.

Now that is a head scratcher. The gust lock was off, the gust lock latch was not in the locked position, yet the elevator remained in the down locked position.

I had a non-rotation event happen to me once at V-R. Let me tell you, it takes a few seconds to comprehend that the aircraft did not rotate. I did manage to get the aircraft in the air right at the end of the runway by using full aft yoke and applying up trim at the same time.

If I had not been able to get airborne, we'd gone into a river at a very high rate of speed. Stopping on the remaining runway was out of question at V-R, there was not enough runway left to get the aircraft stopped on.

This was in a Westwind II and it was a forward CG issue that I was unaware of. Still would have been my fault if we had crashed.

testpanel

13th Jun 2014, 18:02

Review of FDR data parameters associated with the flight control surface positions did not reveal any movement consistent with a flight control check prior to the commencement of the takeoff roll.

That could be important.

letsjet

13th Jun 2014, 18:34

Prelim. NTSB Report snip...

"Review of FDR data parameters associated with the flight control surface positions did not reveal any movement consistent with a flight control check prior to the commencement of the takeoff roll."

It just goes to show how important these checks are.

Very skilled and experienced pilots.....

Astra driver

13th Jun 2014, 18:37

Copied and pasted from a G550 after engine start checklist. (A GIV would be essentially the same)

3. EMERGENCY POWER ..............
4. DOORS ..........................................................CL OSED
5. APU .............................................. ON / AS REQUIRED
6. BLEED AIR Control Panel ...................................... SET
7. FUEL SYSTEM Panel ............................................ SET
8. COWL ANTI-ICE (2) / WING ANTI-ICE (2) ....... AS REQ
A. L / R COWL / WING ANTI-ICE ................................
..................................... ON (MANUALLY SELECT)
B. ³$I´ IFRQ LQ 7G7 GaJH ......................... DISPLAYED
C. Cowl Anti-Ice / Wing Anti-Ice, L-R Messages .......
........................................................... DISPLAYED
D. L / R COWL / WING ANTI-ICE ................................
.......................................... AUTO / AS REQUIRED
E. ³$I´ IFRQ aQG &$6 0HVVaJHV ........................... OFF
9. ANTI-ICE HTR (4) .................................................... ON
10. WINDSHIELD HEAT (2) ........................................... ON
11. CABIN PRESSURE AUTO / SEMI ...................... AUTO
12. Flight Controls 2/3 Synoptic Display ................ SELECT
13. Ground Spoilers (First Flight of Day) ............ CHECKED
14. Stall Barrier (First Flight of Day) ........................... TEST
15. Flight Controls / Bungees ............................. CHECKED
16. NOSE WHEEL STEERING POWER ........................ ON
17. YAW DAMP .......................................................... ENG
18 Standby Electrical Power System (HMG) .......... CHECK

Note item 15, " Flight Control / Bungees" check. Required on every flight
.
Also many Gulfstream crews perform this check as a "Line up" check as well.
It would seem that this unfortunate crew may have missed this critical check.

A copy of the NTSB preliminary report was just sent out company wide by both our Chief Pilot and our Director of Maintenance, I foresee a mandatory control check being required as a "line up" item for all aircraft in our fleet in the very near future.

FrankR

13th Jun 2014, 18:42

I wonder if the FDR or CVR recorded the after start control check?

Astra driver

13th Jun 2014, 18:47

Mutt,
Quote, "I thought that the elevator stayed in the same slightly down position if the lock was engaged or not engaged, the lock just stopped it moving with the wind."

On the legacy Gulfstream models, G550 and earlier, the control column will fall full forward (nose down) when the control lock is released and the controls are not air loaded.

(On the G650, which is FBW, the control column stays in the upright, neutral position at all times unless it is moved. As a side note, there is no control lock on the G650.)

Astra driver

13th Jun 2014, 19:00

Gulfstream just distributed this "MOL"

TO:
SUBJECT:
MAINTENANCE AND OPERATIONS LETTER
June 13, 2014 ALL-MOL-14-0015
FLIGHT CREW OPERATIONAL INFORMATION
All Gulfstream Operators
General (ATA 00) – Airplane Flight Manual (AFM) Procedures
Gulfstream is issuing this Maintenance and Operations Letter (MOL) to remind flight crews of the
importance of adhering to flight procedures published in applicable Airplane Flight Manuals (AFM) to confirm flight control integrity and freedom of motion. Flight crews are reminded to perform the following as set forth in the applicable AFM procedures for each model aircraft.
 Ensure the gust lock is OFF prior to starting engines (not applicable for G650)
 Check flight controls for freedom and correct movement prior to taxi/takeoff
 Confirm the elevators are free during the takeoff roll
If you have questions or comments regarding this communication, please contact Customer Support at 800-810-GULF (4853) or 912-965-4178, by fax at 912-965-4184, or by electronic mail at [email protected].

testpanel

13th Jun 2014, 19:30

I wonder if the FDR or CVR recorded the after start control check?

CVR (verbal) info does not mean sh¿t if investigating actual actions.....

tlbrown350

13th Jun 2014, 19:52

I guess the key word is "consistent" in this report. It begs the question on how they were able to set T/O thrust if the gust lock was engaged.

"The FDR data revealed the elevator control surface position during the taxi and takeoff was consistent with its position if the gust lock was engaged."

"The airplane was equipped with a mechanical gust lock system, which could be utilized to lock the ailerons and rudder in the neutral position, and the elevator in the down position to protect the control surfaces from wind gusts while parked. A mechanical interlock was incorporated in the gust lock handle mechanism to restrict the movement of the throttle levers to a minimal amount (6-percent)"

jdkirkk

14th Jun 2014, 05:02

"A mechanical interlock was incorporated in the gust lock handle mechanism to restrict the movement of the throttle levers to a minimal amount (6-percent)"

So was the throttle restrictive feature of the gust lock mechanism designed with failsafe feature(s)? (Sounds like it was.)
Were there any write-ups on the gust lock operation?
Why was this system design deleted in later model aircraft?
Has anyone on this forum flown this model aircraft?
I understand the visible handle of the gust lock was observed to be in the OFF position, and that portion of the cockpit appears intact.
It's my understanding that if the gust lock feature was engaged he couldn't have advanced the throttle for TO.

ericthepilot

14th Jun 2014, 06:53

Cant find the link to that document .....

Hadley Rille

14th Jun 2014, 10:13

Can somebody please explain how the elevator "correct sense" check is carried out on this type of aircraft?

JRBarrett

14th Jun 2014, 11:57

Can somebody please explain how the elevator "correct sense" check is carried out on this type of aircraft?

There really is no "correct sense" check that can be done by the flight crew, insofar as determining from the flight deck that the elevator moves on the correct direction - i.e. up with aft yoke movement, and down with forward yoke movement. Unlike later models like the G-550, the G-IV has no control surface position displays on the flight deck for ailerons, elevators or spoilers.

The only check that the crew can do is to insure that the flight controls have full freedom of movement before flight. Based on the NTSB preliminary report, the FDR data does not indicate that this was accomplished prior to commencing takeoff - potentially a key omission.

Obviously the pitch control system was working on the aircraft's inbound flight to BED from ACY, so whatever failure occurred to prevent rotation, happened at some point between landing and the next (unsuccessful) attempt to take off.

VFD

14th Jun 2014, 13:00

I understand the visible handle of the gust lock was observed to be in the OFF position, and that portion of the cockpit appears intact.
It's my understanding that if the gust lock feature was engaged he couldn't have advanced the throttle for TOThat is what baffled me at first until this clue.
On the legacy Gulfstream models, G550 and earlier, the control column will fall full forward (nose down) when the control lock is released and the controls are not air loaded.The actual locking device is armed to engage or disengage with the lever along with the throttle block.
However, in some form or fashion mechanically or hydraulically the elevator mechanism has to be separated from the yoke and commanded down for the lock to engage.
So obviously the falling forward of the yoke realigns the yoke or doing control checks accomplish the same result of resetting the yoke to the elevator commands.

If the pilots were holding neutral position of the yoke, released the gust lock on taxi and then the lock itself would disengage, BUT did not do control check then the yoke would not reset itself to align with the elevator control commands.

So by falling out of normal start sequence they missed both opportunities to realign/reset the elevator functions.
That is my limited interpretation anyway.

Hadley Rille

14th Jun 2014, 13:42

Thanks for the reply JRB. It's odd that a check that's so simple in a SEP is effectively not done in a more sophisticated aircraft (without position displays).

jdkirkk

14th Jun 2014, 17:48

“If the pilots were holding neutral position of the yoke, released the gust lock on taxi and then the lock itself would disengage, BUT did not do control check then the yoke would not reset itself to align with the elevator control commands.”

“The report also indicated a possible problem with a mechanical gust lock system, which protects aircraft components from wind damage while planes are parked. Aviation experts say the plane would have been unable to take off if the lock was engaged.”

As I understand this situation, you might set the gust lock to protect the parked airplane before you leave because it will be sitting for a while.
Then you get a call on the cellphone alerting you that the passengers are on the way to the airport. One thing you visually check in the cockpit is that the gust control lever is OFF either before or during the reading of the checklist. The Captain was also a mechanic so he would probably see things that the average pilot, like me, might miss. A friend of mine was Maintenance Officer at a USAF ADC base in MA back in the fifties and he used to take a random mechanic off the flight line on test hops of one of his F89’s, a move calculated to help avoid another reverse control hookup he had experienced.

Question: Placing the gust control lever in the OFF position in this Gulfstream does not actually turn the gust control OFF until - and unless - you do a control check?

I would think that placing the Gust Control Lever to the OFF position would turn the Gust Control OFF.

Gulfstream builds a nice airplane – why the extra step to turn the Gust Control OFF? You will have your hands on the controls as you start the TO roll and that feel will tell you if things are normal whether or not you actually did a full control check. The B767 was the last plane I flew and its controls were pretty simulator-like numb but you would know early on if they were not right. The Gulfstream is very light by comparison and would have a very lively feel I would think.

Admittedly I am out of the loop age-wise but I recall, for instance, a young USAF pilot flying strip alert take off with his seat belt inadvertently unfastened. Checklists are handy but do not cover all categories, especially if you are in a hurry, or hurried.

I am curious because apart from the tragedy of the deaths of those on this airplane, I was startled to read recently that Gulfstream lost a brand new airplane with their own test pilots on a test hop. I do not know what caused this accident but if that particular Gulfstream crew, or engineering staff, missed something, there may be something more than the infamous pilot error afoot here.

Each death is an individual heartrending tragedy to all, and the particular loss of Lewis Katz is a big loss to the community as well. He helped a lot of people.

Aircraft accidents are the biggest learning curve we surf in this industry, and as Ernie Gann pointed out, Fate is out there looking for each of us. That you have never scratched an airplane does not mean that you won’t, or can’t.

JRBarrett

14th Jun 2014, 17:59

That is what baffled me at first until this clue. The actual locking device is armed to engage or disengage with the lever along with the throttle block. However, in some form or fashion mechanically or hydraulically the elevator mechanism has to be separated from the yoke and commanded down for the lock to engage. So obviously the falling forward of the yoke realigns the yoke or doing control checks accomplish the same result of resetting the yoke to the elevator commands. If the pilots were holding neutral position of the yoke, released the gust lock on taxi and then the lock itself would disengage, BUT did not do control check then the yoke would not reset itself to align with the elevator control commands. So by falling out of normal start sequence they missed both opportunities to realign/reset the elevator functions. That is my limited interpretation anyway. VFD

It's not quite as complicated as that, there is no mechanical or hydraulic "separation" of the yoke from the elevator. Pulling the control lock lever upward merely causes a latching pin to slide into a matching hole in one of the bellcranks which are part of the normal elevator mechanical control interconnection from the flight deck to the aft equipment bay. Pushing the control lock lever down causes the latching pin to retract. The latching pins for elevator, ailerons and rudder are all controlled by cables which have a common connection at the lock lever.

The elevator's natural position on the ground with no hydraulic power applied is fully down, which corresponds to the yoke being fully forward. The position where the locking latch will engage is very close to the full down position. When engaging the lock, the pilot might have to pull the yoke back an inch or two until the lock lever will come fully up, but it is not a significant distance.

The preliminary report indicates that the locking latch for the elevator was found disengaged, and though it could have retracted from the impact forces of the crash, I would think that if it HAD been engaged at impact, there would have been some mechanical damage to the latch, or it's mounting bracket - apparently there was no indication of that.

From a psychological perspective, I would think that if the yoke was locked, or mechanically jammed in such a way that the yoke could not be pulled back - that the pilot's instinctive reaction would have been to instantly recognize that a serious problem existed, and to have initiated an abort immediately.

Instead, all indications are that the abort was only initiated many seconds after VR, which seems to point to the possibility that the yoke came back normally, and the problem was not recognized until the nose failed to rise as would be expected in a typical rotation, consuming many precious seconds, and many hundreds of feet of remaining runway.

If so, this would point to a failure in the mechanical control path between yoke and elevator in which the elevator did not respond to movement of the yoke.... but in such a way that the yoke travel was not restricted. A broken control cable would be my first thought - but there are other possibilities.

glendalegoon

14th Jun 2014, 19:09

see post 38.

areobat

15th Jun 2014, 14:32

con-pilot

15th Jun 2014, 17:47

Instead, all indications are that the abort was only initiated many seconds after VR, which seems to point to the possibility that the yoke came back normally, and the problem was not recognized until the nose failed to rise as would be expected in a typical rotation, consuming many precious seconds, and many hundreds of feet of remaining runway.

My thinking is trending to go in that direction. Based on an incident that happened to me back in 1981 when the aircraft I was flying failed to rotate at V-R. There is a WTF pause at that moment, that costs some time, precious time I might add.

In my case I was able to finally rotate with full up elevator while applying up trim. There was not enough runway left to consider an abort. The cause was a forward CG issue that I was not made aware of.

JPJP

15th Jun 2014, 18:33

chuks

15th Jun 2014, 22:43

If no maintenance was carried out during the stop, the normal control check for freedom of movement could be safely assumed to also be a check for correct movement.

It's interesting that the initial report says that there was no evidence of a control check prior to takeoff. That would mean that if there was some restriction to free movement of the elevator, that would only have become apparent at some time during the takeoff.

That said, though, I doubt that the control column should remain fully or almost fully forward during the takeoff roll, where it would be with the aircraft stationary with the controls locked. You would expect it to sort of "float" backwards to a neutral position in response to air loads, the column position corresponding to the elevator position, ready for the nose-up input associated with the "Rotate" call at VR. Not seeing the column move in that way should have triggered some sort of response from the crew, so that a working assumption would be that the control column did move aft in the normal way. This logic I am using argues that the controls were not locked.

This is still a puzzling accident, so that it will be very interesting to read the final report, but reading that there's no evidence of a control check seems to be one piece falling into place.

fleigle

16th Jun 2014, 01:51

JPJP
Do you think that if the flight crew escaped uninjured after the crash that they would be concerned about flap position for an emergency exit ?????
:ugh:

JRBarrett

16th Jun 2014, 02:29

From the report - "The flap handle in the cockpit was observed in the 10 degree detent. FDR data indicated a flap setting of 20 degrees during the takeoff attempt." The disagreement between the flap handle position (10) and the flap setting during takeoff (20) is interesting. Does Gulfstream specify a flap setting prior to an evacuation ?

Although the cockpit section of the airframe appeared relatively intact in the post-crash photos, hard to say how much structural damage occurred inside, or how severe the deceleration forces were. The flap handle has a latch that locks it into place at each detent, but quite possible I suppose, that it could have been driven forward from 20 to 10 degrees in the crash - especially if it was hit by something from behind, or if the linkage below the flap handle broke off.

Would explain the initial mystery of why the crew seemingly chose to do a Flaps 10 takeoff, when conditions didn't really call for it. If the FDR record is accurate, it was a standard Flaps 20 departure after all.

JRBarrett

16th Jun 2014, 02:57

I was thinking cable problem, but not the yolk to elevator cable, rather, the cable the actuates the pin on the elevator lock. If this cable were damaged and/or mis-adjusted, the locking pin may have pulled out part way thus temporarily freeing the elevator mechanism, but after the take-off roll commenced, the vibration, movement, ect., may have caused the pin to re-engage the lock hole thus freezing the elevator. I'm not familiar with the gust lock mechanism on the GIV so I don't know exactly what the failure modes are, so this is a bit of speculation on my part.

That possibility has crossed my mind. However, during my initial maintenance training on the G-IV many years ago, we were told that the hydraulic actuators are capable of producing more than enough force to shear the lock latches right off of their mounting brackets if the associated flight controls are moved forcefully in the cockpit. One reason why the checklist calls for the control lock lever to be released before engine start.

I don't know about the aileron and elevator locks, but there have apparently been several incidents in the G-IVs history of flight crews breaking the rudder control lock by pressing a rudder pedal after engine start with the lock lever still engaged.

Though, that probably would be easy to do, as the rudder has the largest and most powerful hydraulic actuator in the entire flight control system.

areobat

16th Jun 2014, 16:13

That possibility has crossed my mind. However, during my initial maintenance training on the G-IV many years ago, we were told that the hydraulic actuators are capable of producing more than enough force to shear the lock latches right off of their mounting brackets if the associated flight controls are moved forcefully in the cockpit. One reason why the checklist calls for the control lock lever to be released before engine start.

I don't know about the aileron and elevator locks, but there have apparently been several incidents in the G-IVs history of flight crews breaking the rudder control lock by pressing a rudder pedal after engine start with the lock lever still engaged.

Though, that probably would be easy to do, as the rudder has the largest and most powerful hydraulic actuator in the entire flight control system.I'm sure that is true when the aircraft is either not moving or moving slowly and the air pressure on the control surfaces is zero or near zero. But what happens around Vr speeds when the aerodynamic forces on the elevator and other control surfaces are quite high? Under these conditions, the hydraulic actuator(s) has to over come the aerodynamic force plus the force necessary to "shear" the locking pin. It may be that the sum of these two forces was greater than that which the hydraulics could supply. Just a thought.

JPJP

16th Jun 2014, 16:45

fleigle- JPJP
Do you think that if the flight crew escaped uninjured after the crash that they would be concerned about flap position for an emergency exit ?????:ugh::ugh:

Easy tiger. There's no need to get worked up.

To answer your question - Yes, if the crew had escaped the impact uninjured or injured, they may have performed some of the evacuation checklist. Which, as I'm sure you know, often involves a specific flap setting other than the one used for takeoff.

Given the forces involved I think it's unlikely. However, I was curious about the disagreement between the flap settings. Now that you understand the point, do you have anything to offer ? (Apart from banging your head against a wall).

jdkirkk

16th Jun 2014, 21:35

NTSB Identification: ERA14MA271
14 CFR Part 91: General Aviation
Accident occurred Saturday, May 31, 2014 in Bedford, MA
Aircraft: GULFSTREAM AEROSPACE G IV, registration: N121JM
Injuries: 7 Fatal.
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators traveled in support of this investigation and used data obtained from various sources to prepare this aircraft accident report.
On May 31, 2014, about 2140 eastern daylight time, a Gulfstream Aerospace Corporation G-IV, N121JM, operated by SK Travel LLC., was destroyed after a rejected takeoff and runway excursion at Laurence G. Hanscom Field (BED), Bedford, Massachusetts. The two pilots, a flight attendant, and four passengers were fatally injured. Night visual meteorological conditions prevailed and an instrument flight rules flight plan was filed for the flight destined for Atlantic City International Airport (ACY), Atlantic City, New Jersey. The business flight was conducted under the provisions of 14 Code of Federal Regulations Part 91.

The airplane was based at New Castle Airport (ILG), Wilmington, Delaware, and co-owned by one of the passengers, through a limited liability company. According to preliminary information, the airplane departed ILG earlier in the day, flew to ACY, and then to BED. The airplane landed at BED about 1545 and remained parked on the ramp at one of the fixed base operators. The crew remained with the airplane until the passengers returned. No maintenance or fuel services were requested by the crew.

The airplane was subsequently cleared for takeoff from runway 11, a 7,011-foot-long, 150-foot wide, grooved, asphalt runway. A witness observed the airplane on the takeoff roll at a "high speed" with "little to no altitude gained." The airplane subsequently rolled off the end of the runway, on to a runway safety area, and then on to grass. The airplane continued on the grass, where it struck approach lighting and a localizer antenna assembly, before coming to rest in a gully, on about runway heading, about 1,850 feet from the end of the runway. A postcrash fire consumed a majority of the airplane aft of the cockpit; however; all major portions of the airplane were accounted for at the accident site. The nose gear and left main landing gear separated during the accident sequence and were located on the grass area between the safety area and the gully.

Tire marks consistent with braking were observed to begin about 1,300 feet from the end of runway 11. The tire marks continued for about another 1,000 feet through the paved runway safety area.

The airplane was equipped with an L-3 Communications FA-2100 cockpit voice recorder (CVR) and an L-3 Communications F1000 flight data recorder (FDR), which were recovered and forwarded to the Safety Board's Vehicle Recorders Laboratory, Washington, DC for readout.

Initial review of CVR and FDR data revealed that the airplane's ground roll began about 49 seconds before the end of the CVR recording. The CVR captured callouts of 80 knots, V1, and rotate. After the rotate callout, the CVR captured comments concerning aircraft control. FDR data indicated the airplane reached a maximum speed of 165 knots during the takeoff roll and did not lift off the runway. FDR data further indicated thrust reversers were deployed and wheel brake pressures increased as the airplane decelerated. The FDR data ended about 7 seconds after thrust reverser deployment, with the airplane at about 100 knots. The FDR data did not reveal evidence of any catastrophic engine failures and revealed thrust lever angles consistent with observed engine performance. Review of FDR data parameters associated with the flight control surface positions did not reveal any movement consistent with a flight control check prior to the commencement of the takeoff roll. The flap handle in the cockpit was observed in the 10 degree detent. FDR data indicated a flap setting of 20 degrees during the takeoff attempt.

The airplane was equipped with a mechanical gust lock system, which could be utilized to lock the ailerons and rudder in the neutral position, and the elevator in the down position to protect the control surfaces from wind gusts while parked. A mechanical interlock was incorporated in the gust lock handle mechanism to restrict the movement of the throttle levers to a minimal amount (6-percent) when the gust lock handle was engaged.

The FDR data revealed the elevator control surface position during the taxi and takeoff was consistent with its position if the gust lock was engaged. The gust lock handle, located on the right side of the control pedestal, was found in the forward (OFF) position, and the elevator gust lock latch was found not engaged.

The wreckage was retained for further examination to be performed at a later date. The airplane was also equipped with a quick-access-recorder (QAR), which was retained for download.

The certificated airplane transport pilot, who was seated in the right seat, reported 18,500 hours of total flight experience on his most recent application for a Federal Aviation Administration (FAA) first-class medical certificate, which was issued on February 4, 2014.

The certificated airline transport copilot, who was seated in the left seat, reported 11,250 hours of total flight experience on his most recent application for an FAA first-class medical certificate, which was issued on April 15, 2014.

Both pilots completed a Gulfstream IV recurrent pilot-in-command course and proficiency check during September 2013. At that time, the pilot and copilot reported 2,800 and 1,400 hours of total flight experience in G-IV series airplanes; respectively.

Initial review of maintenance records revealed that at the time of the accident, the airplane had been operated for about 4,950 total hours and 2,745 landings.

The reported weather at BED, at 2156, included calm winds, visibility 10 miles; clear skies; temperature 8 degrees Celsius (C); dew point 6 degrees C; altimeter 30.28 inches of mercury. Index for May2014 (http://www.ntsb.gov/aviationquery/AccList.aspx?month=5&year=2014) | Index of months (http://www.ntsb.gov/aviationquery/Month.aspx)

jdkirkk

16th Jun 2014, 22:19

It seems there is a question remaining on the flight controls Gust Lock.
The Gust Lock Handle was in the OFF position. Normal.
The throttles could be advanced and that indicates the Gust Lock was not engaged. Normal.
I’m uncertain what the FDR is recording; where it was getting its info that the Gust Lock was indicated ON? Abnormal.
Many pilots go forward – aft - left – right on the yoke as a matter of habit somewhere before T/O. This report says the FDR did not record a control check. What was it looking at?
If the controls were locked they would not have felt right on the TO roll, would not have “lightened up” as Vr approached. That would have alerted the pilot flying.
It had been a long day, but my conversations with corporate pilots indicate that was not unusual.
It was a night VFR takeoff on a dry runway.
No reason to expect anything unusual. The airplane worked fine on the inbound legs.
They apparently hit the brakes and reversed at about 165 kts, possibly around the 5500’ point on the 7100’ runway and stopped when they hit the ditch about 1850’ beyond the end of the runway.
Pretty skinny looking tires so braking would not appear to be really significant; but they were hard on the binders because the nose and one landing gear sheared off in the overrun. The wheels were probably not turning much due antiskid.
It takes a couple or three seconds at least for the thrust reversers to work.
They did everything they could but something appears to have been broken between the yoke and elevator.
This was a very expensive, sophisticated airplane, with primary and backup systems that had a lengthy and normal history. What went wrong?

fleigle

16th Jun 2014, 23:56

JPJP
Sorry, I'd had a bad day and a couple of glasses of wine...:ouch::ouch:
However, given the impact I really doubt that there was any checklist reading going on afterward.
I was involved in a serious car collision at a lot less than 100 knots and I was in no shape to do anything coherent for quite a few minutes afterwards.

Old Boeing Driver

17th Jun 2014, 00:50

I can't recall this ever happening, but what is the possibility that they pulled the yoke back at Vr and nothing happened. (meaning the yoke actually moved)

What would have to break for that to happen?

Brian Abraham

17th Jun 2014, 01:48

Comments from an experienced pilot on type “The position of the controls recorded by the FDR was pretty consistent with where the flight controls normally rest during taxiing,” he said. On this basis, the gust lock theory would seem less plausible........He explained that part of the Gulfstream takeoff procedure includes feeling the controls lighten as air moves across the tail surfaces early in the takeoff roll. “If we don’t feel that by 60 knots or so, it’s an automatic abort,” he added, while also questioning the takeoff speeds mentioned in the report. “At a light [takeoff] weight, the V1 speed of the GIV should have been about 118 knots,” he said, “with rotation at about 124.” This prompted him to question why the aircraft reached a speed of 165 knots before the crew aborted the takeoff.

Preliminary GIV Crash Report Focuses on Flaps and Gust Lock | Aviation International News (http://www.ainonline.com/aviation-news/ainsafety/2014-06-16/preliminary-giv-crash-report-focuses-flaps-and-gust-lock)

jdkirkk

17th Jun 2014, 02:25

This is very, very speculative at best . . .
Maybe their procedure was to swap legs, and the pilot doing the flying did so in the left seat, but the Captain was still in charge.
In my experience one guy flies, and one guy talks, and it seems to work reasonably well. In the military we sometimes changed seats, but not in the airlines.
I seem to recall that the guy doing the flying could always reject the takeoff, although I’m certain this got exciting at times.
(I flew for PAA for years and the first thing any F/O checked out on a flight was the mood of the Captain.)
If in doubt, reject, and we’ll discuss it later.
Both pilots had plenty of time, type ratings for the airplane, and ATP licenses, so they were working at it.
Also, they had recently passed sim checks, so they were up to speed on the unusual stuff.
The lower time pilot was doing the flying from the left seat – I assume.
At V1 everything is fine, at Vr it doesn’t, and when the nose doesn’t come up, you would say “what the H” because this is not something you have ever experienced, or heard of, before.
You have possibly eaten up 4500’ of runway before the other pilot agrees there is a problem and the reject starts. Now you are at the 6000’ feet of runway and shortly realize you are not going to stop on the runway.
We are so primed for a fire or an engine failure, maybe a runaway stabilizer control problem, but I do not recall a control not working at all.
Ailerons rigged to work backwards maybe, but elevators not working at all, is a new one.
Gulfstream builds a great airplane with quite a reputation so we will soon know what happened.
And I think the new airplanes with the fly by wire stuff might lead to more of this, so know where the breakers are . ..

jdkirkk

17th Jun 2014, 15:10

From #167 above . . .http://www.pprune.org/members/75111-brian-abraham

Comments from an experienced pilot on type

“He explained that part of the Gulfstream takeoff procedure includes feeling the controls lighten as air moves across the tail surfaces early in the takeoff roll. “If we don’t feel that by 60 knots or so, it’s an automatic abort,” he added, while also questioning the takeoff speeds mentioned in the report. “At a light [takeoff] weight, the V1 speed of the GIV should have been about 118 knots,” he said, “with rotation at about 124.” This prompted him to question why the aircraft reached a speed of 165 knots before the crew aborted the takeoff.”

I’m guessing the pilot in charge will buy the accident because he did not start the reject procedure in time to stop the airplane on the available runway.

That whatever the problem with the control(s) might have been there was time for a proper reject of the takeoff.

But it will be most important to discover the reason for the question on the flight controls.

Modern aircraft are so good that you only get to try emergency procedures in the simulator, and when something does go wrong in the real world it tends to be something strange not practiced in those sim rides.

I’ve heard some scary stories about flying the rich folks around and some of the tiny airports they fly into. It has never been a world I wanted any part of, but admittedly the newer airplanes look very nice indeed. But the pilot is always the first to arrive at the scene of the accident, and they seldom get a voice in the investigation.

Given the high quality of the crew and a really first class airplane, I would have been happy to be aboard that flight because Lewis Katz was a class guy who took good care of people. Everyone involved was doing their very best, but sometimes Fate decides that isn’t enough.

But that won’t be mentioned in the final accident investigation report.

jdkirkk

17th Jun 2014, 18:52

Engineered Material Arresting System (EMAS)

Here is something we can all do, or try to do.
I live in Goleta, CA, and my family uses the Santa Barbara Airport (SBA).
(Actually, I’m an 80 year old fat guy with Parkinson’s and flying on anything is not something I consider pleasant anymore.)
They are going to have a Master Plan Public Meeting at the SBA airport on June 26. This will be at 6:00 – 7:30 PM when I like to be comfortable in front of the TV.
There are several major airlines and many business and private aircraft that use this airport.
It has two runways, only one of which 7/25, is suitable for airline traffic and it has deep ditches at both ends.
The airport was built during WW2 in a swampy area W of the city.
Look up SBA Rwy 7/25 on Google Earth and you will see the situation.
Actually, the short runway also has a ditch at one end . . .
In reading the comments on this accident one person mentioned better, safer, use of the overrun.
http://www.faa.gov/news/fact_sheets/news_story.cfm?newsId=13754
The ditch at Hanscom that killed some good people and destroyed a good airplane could have been fixed real easy and this accident would be an incident being discussed over a beer by those involved.
A length of concrete pipe in the ditch to let the water find a way downstream and dirt on top of the pipe planted in greenery would do the job.
It would be much less expensive than flying a load of Marines in a B747 to Iraq, for instance.
Take some of the photos of this accident with you and point out that it could easily happen right here in River City, maybe with them on board.
Talking to a Board of this type is sometimes not particularly pleasant so, if necessary, take someone with you that understands the bureaucratic language. Pay a visit to the local newspaper, brief them on the situation, and they might be interested enough to cover the meeting.

glendalegoon

22nd Jun 2014, 19:25

I knew someone who took off in a DH twin otter with the controls locked.

they got airborne and nearly stalled, the captain reduced power and the nose came down, they got things under control and came back to land.

both got time off from the company and the FAA.

DO YOUR CHECKLISTS!

jdkirkk

22nd Jun 2014, 22:19

Investigators Analyze GIV Controls, Gust Lock In Hanscom Crash
Jun 13, 2014John Croft (http://aviationweek.com/author/jcroft) | AWIN First

Recovered recorders from Bedford, MA, Gulfstream incident May 31
NTSB

NTSB (http://awin.aviationweek.com/OrganizationProfiles.aspx?orgId=26686) investigators say the pilots of a Gulfstream IV that was destroyed after a rejected takeoff and runway excursion at Hanscom Field on May 31 did not perform a pre-takeoff control surface movement check.
According to a preliminary report released today (http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20140531X32035&key=1), the flight data recorder (FDR) parameters associated with flight control surface positions "did not reveal any movement consistent with a flight control check prior to the commencement of the takeoff roll." Control surface movement checks are typically standard checklist items before departure.
At the "rotate" speed where the pilots pull back on the elevator control to lift off, the crew discussed "comments concerning aircraft control," according to the cockpit voice recorder. Though traveling as fast as 165 kt. during the attempted departure, the aircraft did not lift off, and pilots shortly thereafter began applying brakes and reverse thrust in an attempt to stop. The FDR showed the flaps to be set at the typical value of 20 deg., although the lever in the cockpit was set to 10 deg.
Skid marks were found on the final 2,300 ft. of runway and overrun area, with the aircraft traveling another 1,850 ft. through grass, hitting approach lighting and localizer equipment before coming to rest in a gully and burning. All seven on board were killed.
The missing check could be significant, as a primary factor or a distraction, as investigators also found that the elevator surface position during the taxi and takeoff "was consistent with its position if the gust lock was engaged." The aircraft has a mechanical gust lock system, which locks the ailerons and rudders in the neutral position and the elevator in the down position as a method of protecting the surfaces from wind gusts while the aircraft is parked. The system is also supposed to prevent the throttles from being pushed to takeoff power with the lock engaged. Post-crash, investigators found that the gust lock handle, located on the right side of the control pedestal, was in the forward, or "OFF" position, and the elevator gust lock latch not engaged however.
The NTSB says the FDR data also showed that the two Rolls-Royce (http://awin.aviationweek.com/OrganizationProfiles.aspx?orgId=20257) turbofan engines performed as expected, with no evidence of a catastrophic failure.
http://aviationweek.com/business-aviation/investigators-analyze-giv-controls-gust-lock-hanscom-crash

ramble on

23rd Jun 2014, 03:28

Its been some time since the GIV, but the other possibilities here:

1. Pitch Trim incorrectly set.
The GIV has the trim setting marked on the trim wheels next to the seats.

A gotcha early on was that the original GIV trim wheel had no "green band" marked on it and it ran from -8 through 0 to +18 (or so from memory). If you werent careful (tired and on a dark night) it was possible at light weights (which equalled low pitch trim settings) to set a negative trim value of -8 instead of +8. Most experienced operators always set at least +10 to avoid this trap - thus ensuring that they have at least +ve pitch trim set.
It seems unlikey that experienced operators would fall for this trap, but me, I can still fall for any trap when its dark and its been a long day.

Later GIVs now have a "green band" marked on the trim wheel that starts at +8.

I have heard stories about this gotcha in other aircraft types causing aborted takeoffs when the aircraft didnt pitch as expected when the yoke was pulled back..

As previously said - the GIV yoke floats back from the forward stops to just short of mid point position from brake release with the combined forces of accelaration and increasing airspeed. That was always the final check of free movement for me.

2. Flight Control Disconnect
Had this happen once on a JAA registered GIV - pilot induced. The JAA GIVs were modified with a mandatory PCU disconnect feature. It was a JAA specific mod and not required or used in an FAA GIV, but something to ask is - was this previously a JAA aircraft with the mod not removed?
A CAS message would have appeared had this occurred.

JammedStab

24th Jun 2014, 14:18

GIV Pilot Offers Control Lock Operating Suggestions
With NTSB officials acknowledging that control locks are one area of focus in their investigation of the May 31 crash of a Gulfstream IV at Bedford-Hanscom Field Airport near Boston, several active GIV pilots have shared their own standard operating procedures (SOPs) for the equipment with AIN. On June 13, Gulfstream issued a maintenance and operations letter to GIV operators reminding pilots of the importance of following airplane flight manual (AFM) procedures. “Flight crews are reminded to perform the following as set forth in the applicable AFM procedures for each model aircraft: ensure the gust lock is OFF prior to starting engines (not applicable for G650); check flight controls for freedom and correct movement prior to taxi/takeoff; [and] confirm the elevators are free during the takeoff roll,” said the letter from the manufacturer, which is not responding to media questions about the accident pending the NTSB investigation. One GIV pilot based in Asia told AIN, “Our SOPs [also] say do not start engines with the control lock on.” While the engines can be cranked with the locks in place, this same pilot warned that if the engines were started that way, the safest next step would be to shut both engines down and begin again. He did not recommend attempting to disconnect the control lock once the engines are turning.

Why shut down engines when GL engaged?

mutt

24th Jun 2014, 14:54

Why shut down engines when GL engaged? To prevent any hydraulic forces acting upon an engaged gust lock, the gust lock should be released prior to engine starting and not engaged until all hydraulic pressures read zero.

Jet Jockey A4

24th Jun 2014, 15:14

Don't know the GIV but what about electrical hydraulic pumps to back up the engine driven pumps?

Wouldn't you have to turn off those too?

ThreeThreeMike

24th Jun 2014, 17:55

I believe the FCOM says that if the gust lock is not disengaged before engine start, the flight power shut off valve should be operated to remove hydraulic power from the control surfaces. The gust lock can then be disengaged without fear of damaging the locking mechanisms.

See post #121 for the system diagram.

jdkirkk

24th Jun 2014, 19:40

So it sounds like the Engine Shut-Down Checklist – whatever it’s called – mentions the Gust Lock Lever, but whether it is set or not is apparently optional.
But the Pre Start Checklist specifically calls for the Gust Lock Lever to be in the OFF position before starting engines, and the Gust Lock Lever was found to be in the OFF position.
. . . and somewhere along the line, after engine start, a Flight Control Check is called for.
It wasn’t mentioned on the FR, which is not the same as not being done.
And an operator recently commented here that the elevator forces are very obvious as speed increases on TO roll.
Maybe the absence of those normal elevator forces started the cockpit conversation noted on the Flight Recorder about “control forces.”
The Captain was also a licensed mechanic and could be expected to know the systems better than an average pilot. He would know of this hydraulic situation vs the control lock vs engine start deal.
And maybe they did the control check and didn’t say it out loud, so the FR didn’t pick it up?
Both pilots had plenty of total flight time, and time in type, so they were in a familiar situation, in a geographic area they were familiar with, the WX is fine, wind calm, runway dry.
Lewis Katz, the owner, was known to be a man of good humor, and not the type to start yelling at his employees.
I don’t know the airplane; but with the engine’s running, all systems go, including specifically hydraulics, what would keep the nose from rising? What was going on with the elevators?
I would guess the control cables withstood the fire and should help the investigators.
The position of the stabilizer trim has not been mentioned in the official releases from the NTSB.
Were there any delays before departure for any reason? Any deferred maintenance until they got home?

galaxy flyer

24th Jun 2014, 20:23

jdkirk,

The problem is the FDR didn't record any movement consistent with a flight control check from the LDVTs, I guess. See the preliminary report. The FDR is separate from the CVR and position of each control should have shown the check.

Since having the hydraulic pressures off the control paths, is it possible at some time those paths were damaged by an engine start with the lock engaged?

JRBarrett

25th Jun 2014, 01:42

Don't know the GIV but what about electrical hydraulic pumps to back up the engine driven pumps? Wouldn't you have to turn off those too?

The GIV only has a single electrically-driven hydraulic pump - the "aux pump". On the ground, it is not capable of supplying hydraulic pressure to any of the primary flight controls affected by the gust lock system. It can be used to lower or raise the flaps, though doing so takes much longer than when the flaps are being driven by engine hydraulics.

The main function of the aux pump on the ground is to supply hydraulic pressure to raise the main entrance door, and to fully charge the brake accumulator prior to setting the parking brake. It can also be used to open or close the nose and main gear doors on the ground.

jdkirkk

25th Jun 2014, 04:44

Does anyone have a schematic of this Gust Control System?
Page #7, Illustration #121 has the G-IV Hydraulic schematic and it shows the hydraulic pressure going from the engine driven pumps to the controls. This system appears to have worked properly since, for example, the airplane taxied out, flaps were extended, and the brakes and reversers worked. No apparent hydraulic problem
This sounds like a situation to be covered in a simulator session, which this crew had completed.
Where is this lock on the controls to the elevator? Why is its apparent system complexity necessary?
This airplane has been around for some time in various configurations; this crew would not have been the first to hurry up to start the engines and then realize the Gust Control was still locked, if this indeed happened.

mutt

25th Jun 2014, 13:12

https://farm4.staticflickr.com/3925/14318212459_26168db5d5_c.jpg

The red lever on the far right is the Gust Lock, the throttles are in their most forward position with the lock engaged.

The gust lock is a mechanical ground safety system that neither affects the
performance of the aircraft nor receives any flight loads. The ailerons, elevators
and rudder are locked against gust loads by mechanical latches operated by the
GUST LOCK handle located on the cockpit center pedestal.

It is not connected to the hydraulic system, but you dissipate the hydraulic system to avoid placing loads on the locks.

jdkirkk

25th Jun 2014, 15:09

Thanks, Mutt.
Hard to miss the big red handle set ON . . . and the throttles full forward.
The below note is from #163, the NTSB preliminary;

“A mechanical interlock was incorporated in the gust lock handle mechanism to restrict the movement of the throttle levers to a minimal amount (6-percent) when the gust lock handle was engaged.

The FDR data revealed the elevator control surface position during the taxi and takeoff was consistent with its position if the gust lock was engaged. The gust lock handle, located on the right side of the control pedestal, was found in the forward (OFF) position, and the elevator gust lock latch was found not engaged.”

So, one item on the Before Starting Engines Checklist is to insure the Gust Lock Handle is OFF.
The NTSB folks found the Gust Lock Handle properly in the OFF position, but the FDR data didn’t agree? Why?
#167 Brian Abraham quote seems to eliminate the problem, unless something else is afoot.

http://www.ainonline.com/aviation-news/ainsafety/2014-06-23/giv-pilot-offers-control-lock-operating-suggestions
The last line from the above quote reads:
“When questioned about the possibility of accidentally engaging the locks, the pilot said, “Engaging the control lock is not a casual maneuver. It takes effort.”

Effort takes thought. I assume the yellow Fuel Cock levers are the start levers. Hard to miss the Gust Lock handle when starting engines, even at night. You’ve started those engines a zillion times and always do it just so.

Maybe an “I’ll do a fast walk-around and you get the clearance and the checklist started deal”?

This was the flight home and it was getting to be a long day.

Or did a pin break or fall out of a connection somewhere? What was different from the hundreds of flights previously? What specifically were the comments captured on the voice recorder?

jdkirkk

25th Jun 2014, 15:19

“Thanks, Mutt.
Hard to miss the big red handle set ON . . . and the throttles full forward.”

Sorry!
The throttles are NOT in the full forward position.
This is “their most forward position with the lock engaged”
Still, they would have advanced the throttles to the TO position – or slightly less if a reduced power TO – which is not possible with Gust Lock engaged. Right?

The conversation on the flight recorder was about controls, not thrust.

Phileas Fogg

25th Jun 2014, 16:09

Might I respectfully ask a question please:

I've read that the crew operated two sectors earlier in the day then rather than take hotel accommodation they lingered around the aircraft whilst the aircraft owner and guests went about their functions in the Boston area.

And I've also read that these two pilots had been flying, operating this aircraft, together for years so I would believe that were they a "sloppy" crew then there would have been an incident long before now.

So my question is might crew fatigue played it part in this unfortunate incident, for how long had the crew been on duty that day, for how many hours had the crew lingered around the aircraft seemingly denied hotel accommodation, what duties had they performed in the days leading up to this incident etc?

formulaben

25th Jun 2014, 16:23

Many FBOs have accommodations that are well equipped for a snooze or general comfort for the pilots who must wait...if you are going to ponder that question I would first see what FBO they stayed at and what they have for a pilot lounge/snooze room.

galaxy flyer

25th Jun 2014, 16:46

The airworthiness question is that it shouldn't have been possible to advance the throttles with the gust lock accidentally left engaged and if it were disengaged the flight controls should have worked properly during the flight control checks and rotate. There's a problem here beyond the crew.

mutt,

Sorry for the plug here, but the GLF is the Harley of Bizjets.

jdkirkk

26th Jun 2014, 04:12

Quote
“There's a problem here beyond the crew.”

I agree.

mutt

26th Jun 2014, 05:17

jdkirkk..... you answered your own question...

“A mechanical interlock was incorporated in the gust lock handle mechanism to restrict the movement of the throttle levers to a minimal amount (6-percent) when the gust lock handle was engaged. The permitted throttle position is no where near the required position for takeoff.

properly during the flight control Unfortunately it doesn't sounds as if this was done. The concept of the check is that the wing flight controls are visually checked with the use of cockpit mirrors, the elevator is checked for bungy protection and the rudders are checked against audio and visual messages.

Just for information, the elevator trim will still move even with the gust lock engaged.

It was said either in this thread or another forum that when the flight controls are hydraulically powered, using sufficient force will actually break the locking mounts.

I'm sure that this scenario will find its way into our next training sessions.

MotCap

26th Jun 2014, 06:05

Originally Posted by glendalegoon

{I knew someone who took off in a DH twin otter with the controls locked.

they got airborne and nearly stalled, the captain reduced power and the nose came down, they got things under control and came back to land.

both got time off from the company and the FAA.

DO YOUR CHECKLISTS!}

I too knew someone who took off, in a Twin Otter, with the controls locked at Peoria, Illinois in the early seventies.

He did a loop to a dirt nap.

I also knew someone who took off in DC-3 from Evansville, Indiana in the mid seventies with the controls locked. They made it airborne for a while, but eventually lost control and crashed, killing the crew and the entire college basketball team on board.

DO YOUR CHECKLISTS!

I flew the GLF's for about twenty years; G-2, 3, 4, 450, 5 & 550.
Best corporate aircraft produced, in my opinion.

I just can't imagine a experienced and professionally trained crew not completing a flight control check somewhere between "after engine start" and "before takeoff"

I have to wonder if there have been any other similar occurrences of this type previously that did NOT result in a incident/crash. Late in my GLF flying career they introduced the "60 knots, elevator free" call out in to training/ops.

Was the "60 kts, airspeed alive both sides, elevator free" call on the CVR?

galaxy flyer

26th Jun 2014, 15:38

MotCap,

And your experience in other corporate jets to justify the GLF being the best is?

jdkirkk

26th Jun 2014, 15:49

Gulfstream builds a great airplane in a competitive market; a known, accepted fact.
This particular airplane was up to date and maintained by the book; an assumed fact.
The pilots flying this particular flight were professional, experienced, trained, and current in all respects.
Weather was not a factor.
Wind calm, runway dry.
“Something” happened and became obvious at a critical point in the TO roll, and the decision to abort the TO was made too late to stop in the remaining runway.
7011’ of runway and 1000’ of overrun for a light airplane maybe should have been enough for a reject even at VR?? I would guess it is, even if barely.
Someone with the airplane charts could apply them to this particular situation and figure out what
IAS/Runway length the abort should have started to enable stopping on the runway.
The NTSB folks will certainly do this.
The NTSB folks will also figure out what the distracting problem was.
I will be curious to find out why the Captain was sitting in the right seat, if illness might have been a factor.
It is rare for one thing to cause an accident.
But we may never know why the pilot flying didn’t stop sooner and evaluate the situation.
Untimely, that is the Captains responsibility.
I assume that is what the NTSB will probably say.

Jet Jockey A4

26th Jun 2014, 16:08

It was "his personal opinion" that's all.

Some people prefer a BMW over a Mercedes or Audi and the same can be said about aircrafts...

Some prefer a Gulfstream over a Bombardier or over a Falcon, no big deal to me and not a relevant factor here in this accident so personally I don't think it should be even brought up in this conversation.

Just my $0.02.

Jet Jockey A4

26th Jun 2014, 16:14

The captain flying in the right seat is often "normal ops" in the corporate world.

In our operation all our pilots are qualified as captains and we rotate seats to get equal time in the left seat. As such the PF is in the left seat while the right seat is the PNF position.

jdkirkk

26th Jun 2014, 20:14

A4
Thank you

In the so-called “good old days” (they weren’t) the aircraft we flew were prone to failures and we were kept up to speed by real emergencies. The emergencies mostly happen in the simulator now and although you can sweat bullets doing the correct procedure well enough to keep the check pilot satisfied, it is a different kind of fear.
That leads to a situation where, when something real happens, like an engine failure, it’s almost hard to accept. The last one I lost was a new engine and was so unexpected it took me a few seconds to call for the right checklist. The flying was not a problem, but the procedure was, because it was unexpected.
The older airplanes had wires connected to controls, and the airplane had a distinct feel in different situations.
I’ve never flown a Gulfstream aircraft and I understand it to be a wonderful state of the art aircraft, but I wonder what kind of language it speaks to the pilot flying it?
I quit flying about twenty years ago, just when the glass cockpit was coming on board, and the most common quote in the cockpit then was “what is it doing now?” Many times, for a while, we weren’t completely sure, and we raised our personal minimums to meet the situation.
Just about this time the controls started getting complex, feeling like simulator controls, the reverse of what had always been the norm. It was always great to get back in the airplane because then it felt like a real airplane. Not so much anymore.
My flying was of a different type in another era and I have no business on this board, and I apologize, but I used to live in PA and Lewis Katz was a huge, huge, loss. When I looked at the situation it was then – and now – difficult to understand.
Good airplane, good pilots, good weather, what happened?
What can we learn from this?
Again . ..

Bill Harris

26th Jun 2014, 23:34

No sir, JD, your experience and insight are most appreciated. Please continue.

I'll agree, "something happened" here to take two seasoned pilots by surprise.

Feathered

27th Jun 2014, 01:41

The ditch at Hanscom that killed some good people and destroyed a good airplane could have been fixed real easy and this accident would be an incident being discussed over a beer by those involved.

A length of concrete pipe in the ditch to let the water find a way downstream and dirt on top of the pipe planted in greenery would do the job.
It would be much less expensive than flying a load of Marines in a B747 to Iraq, for instance.

I'm not sure it's fair to blame the deaths on simply a "ditch." The "ditch" is actually part of the Shawsheen river, and if there had been a smooth bridge over it, there is another branch of the river shortly thereafter, and a wooded area with lots of trees to stop an airplane fast. The whole area is protected wetlands as well.

The river was likely rerouted into that straight line far away from the runway when the runway 11/29 was expanded decades ago, before environmental protections that exist today.

The towns of Lexington and Bedford (the Shawsheen River at that point actually forms the town line) would go absolutely nuts if there was an attempt to disrupt any of the wetlands, and it likely wouldn't be permitted under federal guidelines either. They (and Lincoln and Concord) were aghast when the other runway was moved slightly (on paper and paint only) to provide safety areas.

Given the politics of the area, it would be much easier to simply close the runway or the airport entirely than expand the runway areas or flatten wooded wetlands.

Feathered

27th Jun 2014, 01:46

A recent news report (http://www.bostonglobe.com/metro/2014/06/16/gulfstream-pilots-urged-check-gust-lock-positioning-after-fatal-crash-hanscom/uZTTWJ9CY9hMXXDiyajTbJ/story.html) quoted that NTSB spokesman as saying the gust locks were very "germane" to the investigation but would not elaborate at this time.

It is interesting that the gust locks were found to be off (as normal) but there is still an issue with them with this investigation.

The reason for that discrepancy may be the same as the probable cause of the accident.

ramble on

27th Jun 2014, 03:42

Interestingly:

One or two years ago I heard a rumour of a later updated model of the Gulfstream GIV, the G450, that had damage to its primary flight control system with the suspected cause being improper engagement of the gust lock while there was still hydraulic pressure in the system.

The rumour was that one or more of the flight control actuator mountings had been damaged and the aircraft had flown in that condition for some time.

Dont ask me which flight control axis, what aircraft and where it occurred as I really dont remember but it was a rumour and I would have thought that only damage possible would have been to the locking mechanism and not to the flight control runs.

MotCap

27th Jun 2014, 07:18

OK, the G-650 is excluded.

Operated the G-2,3,4,5,450 & 550 over twenty years. The control lock operated the same in all aircraft.

After engines were shut down it would take a considerable length of time for residual hydraulic pressure to bleed down allowing to engage the control lock.

It was not possible to engage the control lock with hydraulic pressure on the system. The procedure was to move the control wheel until the pressure was relieved, you could feel it release, and the control lock could be engaged.

I doubt you could damage the control locks or flight control system on shut down ...... on start up, that's another story

Bill Harris

27th Jun 2014, 12:47

jdkirkk

27th Jun 2014, 17:23

Quote
Originally posted by Feathered

“Given the politics of the area, it would be much easier to simply close the runway or the airport entirely than expand the runway areas or flatten wooded wetlands.”

http://en.wikipedia.org/wiki/Hanscom_Field

Hanscom is a critical part of the air transportation infrastructure for Massachusetts (http://en.wikipedia.org/wiki/Massachusetts) and the rest of New England (http://en.wikipedia.org/wiki/New_England). As T. F. Green Airport (http://en.wikipedia.org/wiki/T._F._Green_Airport) in Warwick, Rhode Island (http://en.wikipedia.org/wiki/Warwick,_Rhode_Island) and Manchester-Boston Regional Airport (http://en.wikipedia.org/wiki/Manchester-Boston_Regional_Airport) in New Hampshire (http://en.wikipedia.org/wiki/New_Hampshire) have become viable alternatives to Logan International Airport (http://en.wikipedia.org/wiki/Logan_International_Airport) (the region's main commercial airport), Hanscom has emerged as one of the most important airports serving the region's business and general aviation needs.

There are trade-offs in almost every area of our country today between environmental considerations and cultural growth of various kinds, a move I support. I grew up in rural southern Indiana and my Great Grandfather plowed behind a mule, not as efficient as the H Farmall I drove as a kid but certainly more environmentally conscious. I now live in Santa Barbara, CA, and every project of almost any kind starts with concern for the environment.

After the Korean deal ended I was transferred to a base outside Falmouth, MA. I found the locals very friendly, partied heavily, even dated a gal from Ipswich, MA, and did the tourist bit around Concord and Lexington. Well remembered is a graveyard behind the Unitarian Church on the Green in Lexington, a graveyard that contained whole families of children that had died in some epidemic.
That was in the fifties and I’m sure the area has changed, but it was very pretty, and worth a struggle to protect the remaining beauty.

When G-IV N121JM started its TO roll it was just like hundreds of other takeoffs, but this one ended broken in a ravine where it stopped suddenly from 100 mph and the fuel load didn’t have far to go to find ignition. I notice the entry door was open and it is possible that Teresa Bernhoff might have had time to open that door before her world ended.

Had the flight used Rwy 29 instead of 11 they would probably have survived because there was no ditch/river waiting, and even a cleared road leading through the trees. Still, once the airplane lost its gear and was sliding along on it bottom, ruptured fuel tanks would have probably occurred, but the fuel would not have been so concentrated in one place. The what – ifs do not replace the facts that some good folks died and a good airplane is a pile of junk. The locals helped make that choice.

I recall an F100 taking off from a base in Thailand when at Vr the nose wouldn’t come up due to a hydraulic fitting coming loose at the break in the fuselage that opened for engine changes. He hit the brakes, popped the chute, pickled his externals and came to rest in a swamp off the end of the runway, and lived to tell the tale. Fate does not deal an even hand and the laws of probability do not exclude a single one of us.

What I have learned upfront from this tragedy is that the ditches off the ends of the runways at the Santa Barbara Airport SBA should be modified, just in case, and that’s more important than saving the tree frog, or whatever, and a campaign to do just that is now underway.

Feathered

27th Jun 2014, 21:38

Years ago under "mid-2000's" Wetland Regs you could "exchange" wetland areas-- if you had a wetland area that you needed to develop, you could rehabilitate or "adopt" another wetland of equal value through a complicated Federal tapdance. So they are not locked into having to not use the protected wetlands and there is way out. And if the neighboring cities objected, which they could reasonably do, the objection could be overruled on the basis of safety concerns at this airport demonstrated by this incident. I'm all for saving Bugs and Bunnies, but I'm more for saving human lives.

First of all, the area in question is outside the airport boundary. Second, you are not talking about a little wet area, but a river and associated marshy areas. Where would you propose to put the adopted wetland? Also consider that this area feeds municipal wells that provide public drinking water.

When the runway was lengthened many decades ago, there were much fewer protections against wetlands areas and that was as far as anyone could realistically go even at that time with few environmental protections. If there are truly safety concerns, the local towns of Lincoln Lexington Bedford and Concord would be happy to support closing the runway, or at least closing it to jets and/or aircraft in excess of 12,500 lbs gross. If you say that the needs of $40 million jet owners outweigh the local needs of the town and environment, please be prepared for a very long/strong fight by the local towns (and remember they are your opponent, not me).

Remember these are the same towns that objected and nearly succeeded in preventing tree toppings/removal of trees situated on airport property that were infringing on the flight path to Runway 23.

Feathered

27th Jun 2014, 22:00

There are trade-offs in almost every area of our country today between environmental considerations and cultural growth of various kinds, a move I support. I grew up in rural southern Indiana and my Great Grandfather plowed behind a mule, not as efficient as the H Farmall I drove as a kid but certainly more environmentally conscious. I now live in Santa Barbara, CA, and every project of almost any kind starts with concern for the environment.

After the Korean deal ended I was transferred to a base outside Falmouth, MA. I found the locals very friendly, partied heavily, even dated a gal from Ipswich, MA, and did the tourist bit around Concord and Lexington. Well remembered is a graveyard behind the Unitarian Church on the Green in Lexington, a graveyard that contained whole families of children that had died in some epidemic.
That was in the fifties and I’m sure the area has changed, but it was very pretty, and worth a struggle to protect the remaining beauty.

When G-IV N121JM started its TO roll it was just like hundreds of other takeoffs, but this one ended broken in a ravine where it stopped suddenly from 100 mph and the fuel load didn’t have far to go to find ignition. I notice the entry door was open and it is possible that Teresa Bernhoff might have had time to open that door before her world ended.

Had the flight used Rwy 29 instead of 11 they would probably have survived because there was no ditch/river waiting, and even a cleared road leading through the trees. Still, once the airplane lost its gear and was sliding along on it bottom, ruptured fuel tanks would have probably occurred, but the fuel would not have been so concentrated in one place. The what – ifs do not replace the facts that some good folks died and a good airplane is a pile of junk. The locals helped make that choice..

What I have learned upfront from this tragedy is that the ditches off the ends of the runways at the Santa Barbara Airport SBA should be modified, just in case, and that’s more important than saving the tree frog, or whatever, and a campaign to do just that is now underway.

A better approach would be to determine why this particular aircraft could not fly over the runway end, instead of crashing beyond it. The reason for that is the cause of the tragedy, not the wetlands and forest.

The runway did meet all applicable safety requirements, and actually as lengthened many years ago, which provides additional safety to departing aircraft that do not need over 7,000 feet of runway.

If the proximity of the runway to wetlands and forest are found too dangerous to support jet aircraft, the locals would be more than happy to simply support closing the runway to such aircraft (legally it likely would have to be based on gross weight).

Your information from wikipedia is interesting, but reads like it was written by Massport during the Logan Airport 13/31 saga. (and likely was). It completely misses the politics of the public surrounding this public airport. Remember, these are the same folks who were in hysterics when public stimulus money was used to repair the existing taxiways a few years ago and are still pretty sore that a third FBO is about to open. (their reasoning is that fixed cracks allow more jets to taxi, and more FBOs mean more noise over the historical national park that is adjacent).

Remember, although the politically stuffed Massport steamrolls the local towns on many issues, they certainly do have some sway over the local airport. And they are unlikely to support environmental damage to the wetlands that feed town wells, even if laws permitted that. Remember this is the same airport where local towns attempted (and nearly succeeded) in preventing the removal of tree growth into the approach path for runway 23, which IS on airport property.

And do not think that for one second that locals "made the choice" to put that runway there or decided to relocate the river to where it is today. They did not. You could make a similar claim that the aircraft owner "made the choice" not to have a drogue parachute to stop the aircraft in the event of a high speed abort.

Hanscom was built by the state during a prelude to war, improved by the Army/Air Force during WW II, and returned to the state post war. The adjacent Air Force Base still of course exists, but does not own nor operate the runways.

When the Gulfstream 4 began its roll last month, it had over 8,000 feet of pavement in front of it, including the lengthened safety overrun area. The cause of the death and accident is related to why that particular Gulfstream could not take off prior to the end of the runway.

If reminded of the river and wooded wetlands past the airport boundary, would pilots have decided the risk was too great? Runway 29 was also available (actually usually preferred during the no wind conditions such as those that prevailed the evening of the accident), but Rwy 11 was a much shorter taxi distance. Runway 29 also has lowering terrain followed by a water feature if there is an overrun.

Even if the river was not there, eventually an aircraft moving that fast would find a tree, or a boulder, or an incline, or radio building, or something else. Unless we only allow airports in dry lake beds with miles of flat land surrounding every runway, unfortunately a tragedy will happen when a jet attempts to take off without moving flight control surfaces.

Putting an engineered overrun area (EMAS) may be feasible at Hanscom, I am not sure about the civil engineering requirements let alone finding funding to do so. Would that have prevented the post impact fire?

jdkirkk

28th Jun 2014, 16:44

One reason for a site such as this is to relay information that might be of help to those who might get into similar situations. Life seems is a series of correcting mistakes and making assumptions which sometimes turn out to be wrong. I am not qualified to comment on business jet aircraft, but I suspect it can occasionally be a challenging way to travel. The airplanes are owned by people who pay dearly for convenience, their convenience, and while their airplanes are sometimes state of the art, they are often flown to smaller airports and out of the way places. Accidents happen more than I had expected when I started looking into this particular one, and I am not aware of why that problem exists.

My wife recently sat next to a business jet pilot on a commercial flight and she was discussing with him some of the incidents that made their life style “interesting”. It turned out that he spent considerable effort to avoid flying a famous woman to any destination because she was so difficult to satisfy. But the inverse of that situation is having an owner who is such a good guy you don’t want to disappoint him.

Flying a B767 from ORD to LAX in January for a major airline is a pretty easy job because there are many people helping at every stage, so even when the WX sucks there is little to expect in the way of surprises; you have been through this many times before. The many simulator rides have prepared you for most of the problems so it is only the unusual ones that make you earn your pay. Instructor pilots are not paid to be nice guys.

Not so when you are taking a new boss from South Dakota to Pennsylvania in a January snowstorm
and you are the guy filing the flight plan, doing the walk-around, checking the maintenance, the fuel load, the weather, and whether the meals made it to the airplane OK.Oh, and maybe you have never been to ABE, but note the ILS is notamed out, and the other pilot just moved east from sunny California, so he isn’t certain what a cloud looks like.

The Hanscom Field accident seems to have two areas of interest and the NTSB will hopefully discover and soon publish at least some of their findings on this. One involves some problem with the controls, and the other a delayed decision to reject the takeoff.

An unexpected problem with the flight controls is the lead up to the accident, and the failure to reject in a timely manner apparently led to the conclusion. The Gust Lock and hydraulic pressure could lead, again apparently, to a problem with the controls, but why the rejected takeoff was delayed might be more difficult to discern.

This was the fourth leg of a four leg day, and maybe on the inbound leg they were running a little late for an important meeting and rushed to get the Boss to this meeting. The Gust Lock lever is in such a prominent place in the cockpit that it would be almost impossible to miss, but let’s say you rushed it on engine shutdown and locked the controls before the hydraulic pressure fell to zero. Then before Engine Start you properly set the Gust Lock lever to OFF. Could there be some trapped fluid doing unanticipated things?

I do not understand the lack of a control check before TO, if it’s true, and wonder if the looking in the mirror part to check the rudder works well at night.

Meanwhile, take your time, use the checklist, and anticipate something going wrong, because it will.
Better to arrive late than not to arrive at all.

jdkirkk

29th Jun 2014, 17:16

Aviation Investigation Preliminary Report
Crash on takeoff of Gulfstream Aerospace Corporation G-IV
Bedford, MA
May 31, 2014
NTSB Investigation ID: ERA14MA271
Preliminary Report

Preliminary Report issued: June 13, 2014
On May 31, 2014, about 2140 eastern daylight time, a Gulfstream Aerospace Corporation G-IV, N121JM, operated by SK Travel LLC., was destroyed after a rejected takeoff and runway excursion at Laurence G. Hanscom Field (BED), Bedford, Massachusetts. The two pilots, a flight attendant, and four passengers were fatally injured. Night visual meteorological conditions prevailed and an instrument flight rules flight plan was filed for the flight destined for Atlantic City International Airport (ACY), Atlantic City, New Jersey. The business flight was conducted under the provisions of 14 Code of Federal Regulations Part 91.
The airplane was based at New Castle Airport (ILG), Wilmington, Delaware, and co-owned by one of the passengers, through a limited liability company. According to preliminary information, the airplane departed ILG earlier in the day, flew to ACY, and then to BED. The airplane landed at BED about 1545 and remained parked on the ramp at one of the fixed base operators. The crew remained with the airplane until the passengers returned. No maintenance or fuel services were requested by the crew.
The airplane was subsequently cleared for takeoff from runway 11, a 7,011-foot-long, 150-foot wide, grooved, asphalt runway. A witness observed the airplane on the takeoff roll at a "high speed" with "little to no altitude gained." The airplane subsequently rolled off the end of the runway, on to a runway safety area, and then on to grass. The airplane continued on the grass, where it struck approach lighting and a localizer antenna assembly, before coming to rest in a gully, on about runway heading, about 1,850 feet from the end of the runway. A postcrash fire consumed a majority of the airplane aft of the cockpit; however; all major portions of the airplane were accounted for at the accident site. The nose gear and left main landing gear separated during the accident sequence and were located on the grass area between the safety area and the gully.
Tire marks consistent with braking were observed to begin about 1,300 feet from the end of runway 11. The tire marks continued for about another 1,000 feet through the paved runway safety area.
The airplane was equipped with an L-3 Communications FA-2100 cockpit voice recorder (CVR) and an L-3 Communications F1000 flight data recorder (FDR), which were recovered and forwarded to the Safety Board's Vehicle Recorders Laboratory, Washington, DC for readout.
Initial review of CVR and FDR data revealed that the airplane's ground roll began about 49 seconds before the end of the CVR recording. The CVR captured callouts of 80 knots, V1, and rotate. After the rotate callout, the CVR captured comments concerning aircraft control. FDR data indicated the airplane reached a maximum speed of 165 knots during the takeoff roll and did not lift off the runway. FDR data further indicated thrust reversers were deployed and wheel brake pressures increased as the airplane decelerated. The FDR data ended about 7 seconds after thrust reverser deployment, with the airplane at about 100 knots. The FDR data did not reveal evidence of any catastrophic engine failures and revealed thrust lever angles consistent with observed engine performance. Review of FDR data parameters associated with the flight control surface positions did not reveal any movement consistent with a flight control check prior to the commencement of the takeoff roll. The flap handle in the cockpit was observed in the 10 degree detent. FDR data indicated a flap setting of 20 degrees during the takeoff attempt.
The airplane was equipped with a mechanical gust lock system, which could be utilized to lock the ailerons and rudder in the neutral position, and the elevator in the down position to protect the control surfaces from wind gusts while parked. A mechanical interlock was incorporated in the gust lock handle mechanism to restrict the movement of the throttle levers to a minimal amount (6-percent) when the gust lock handle was engaged.
The FDR data revealed the elevator control surface position during the taxi and takeoff was consistent with its position if the gust lock was engaged. The gust lock handle, located on the right side of the control pedestal, was found in the forward (OFF) position, and the elevator gust lock latch was found not engaged.
The wreckage was retained for further examination to be performed at a later date. The airplane was also equipped with a quick-access-recorder (QAR), which was retained for download.
The certificated airplane transport pilot, who was seated in the right seat, reported 18,500 hours of total flight experience on his most recent application for a Federal Aviation Administration (FAA) first-class medical certificate, which was issued on February 4, 2014.
The certificated airline transport copilot, who was seated in the left seat, reported 11,250 hours of total flight experience on his most recent application for an FAA first-class medical certificate, which was issued on April 15, 2014.
Both pilots completed a Gulfstream IV recurrent pilot-in-command course and proficiency check during September 2013. At that time, the pilot and copilot reported 2,800 and 1,400 hours of total flight experience in G-IV series airplanes; respectively.
Initial review of maintenance records revealed that at the time of the accident, the airplane had been operated for about 4,950 total hours and 2,745 landings.
The reported weather at BED, at 2156, included calm winds, visibility 10 miles; clear skies; temperature 8 degrees Celsius (C); dew point 6 degrees C; altimeter 30.28 inches of mercury.

mutt

29th Jun 2014, 19:49

and wonder if the looking in the mirror part to check the rudder works well at night. The mirrors aren't that good, you can only see the outer wings, not a hope of seeing the rudder, but there is an audio chime indicating full rudder movement.

GIVSP

29th Jun 2014, 21:28

jdkirkk,

in response to your post:

"I notice the entry door was open and it is possible that Teresa Bernhoff might have had time to open that door before her world ended".

If you took the time to review the early crash photos, you will note that the main cabin door was closed and only opened later by the firemen. There are several images available, with a basic search, that show the fireman using axes to break the window glass as well as power saws to cut into the cockpit. The main cabin door is still closed in these photos.

I really think that it is pretty offensive to muse about the last moments of the Cabin Attendent, by name, when you obviously know nothing about the accident and nor have you done any basic research.

Sincerely,

A KBED based Gulfstream G-IV Captain.

projectman

30th Jun 2014, 09:55

Is it possible that the gust lock was left ON during takeoff and only when the aircraft failed to get airborne did the pilots place it in OFF?

mutt

30th Jun 2014, 14:01

Is it possible that the gust lock was left ON during takeoff a Did you read the part about the GUST LOCK also locking the throttles?

jdkirkk

30th Jun 2014, 19:19

Quote:
GIVSP
“I really think that it is pretty offensive to muse about the last moments of the Cabin Attendant, by name, when you obviously know nothing about the accident and nor have you done any basic research.”

----------------------------------------------------------------------------------------------------------------------

I apologize for any offensive remarks; that was not the intent.
On some commercial aircraft the flight attendant sits next to the cabin door, and the handle to operate that door is within reach.
In my experience, the flight attendants dedication and training is equal to or superior to that of the flight crew, their actions commendable, and in emergencies often heroic. Their loyalty and faith in the pilot to keep them safe enters the cockpit on every flight.
I did look at some of the photos, but did not see the ones you mentioned with the firemen and the axes.
Thank you for the information. You obviously are in a position to have expert and personal knowledge of all particulars.
By way of possible explanation, like most pilots on this site, I have lost some friends along the way, and for me it is always personal.
That does not excuse my remarks.
I’m sorry.
John

jdkirkk

30th Jun 2014, 19:42

Mutt
Reference Note #182

Thank you for the photo of the throttle quadrant and the explanation of the gust lock.
Given the experience of the pilots and the note elsewhere that apparently they did not do a control check even in a short taxi, which might have revealed the problem, it would seem possible that something outside the cockpit might be a factor.

A control check would have been second nature to them.

Maybe fatigue, get-home-itis, or whatever - or maybe “something” broke at the last second; but why the delayed reject?

ramble on

1st Jul 2014, 08:25

Stop 'transmit' and put your sets on 'receive' for a little bit. As many have said already:

In the GIV if the Gust Lock IS still engaged inadvertantly as you line up for takeoff YOU CANT GET THE THROTTLES UP MORE THAN AN INCH OR THEREABOUTS.

You certainly cannot apply TAKEOFF EPR.

That EPR with the throttle an inch forward might just be perhaps enough to get to a very fast taxi speed by the end of a 7000' runway.

If their GUST Lock was engaged and working properly then the lack of a control check would have been irrelevant because they could not have got the throttles up for take off.

And the great big red Gust Lock lever is right next to the flap handle which makes it very hard to miss.

That leads to a question for experts and technicians:

If they HAD started and taxied with the Gust Lock inadvertently engaged (contrary to the checklist) and then only noticed it that had been accidentally left on and so then released it while hydraulic power was on the flight controls (again contrary to the AFM) is there any chance that the Gust Lock throttle pin could/would release and not the mechanism that locks the flight contols?

Disregard that question above - I missed an important fact. As quoted from the NTSB Preliminary Report, below the flight controls were not locked by the gust lock latch mechanism. When released the GIV yoke sits very close to the position that it is in in the locked position.

Set switched to 'receive'.

jdkirkk

1st Jul 2014, 15:15

Quote
Ramble On

If they HAD started and taxied with the Gust Lock inadvertently engaged (contrary to the checklist) and then only noticed it that had been accidentally left on and so then released it while hydraulic power was on the fight controls (again contrary to the AFM) is there any chance that the Gust Lock throttle pin could/would release and not the mechanism that locks the flight controls?

---------------------------------------------------------------------------------------------------------------------------------------

Quote
Aviation Investigation Preliminary Report#206 Permalink

The airplane was equipped with a mechanical gust lock system, which could be utilized to lock the ailerons and rudder in the neutral position, and the elevator in the down position to protect the control surfaces from wind gusts while parked. A mechanical interlock was incorporated in the gust lock handle mechanism to restrict the movement of the throttle levers to a minimal amount (6-percent) when the gust lock handle was engaged.
The FDR data revealed the elevator control surface position during the taxi and takeoff was consistent with its position if the gust lock was engaged. The gust lock handle, located on the right side of the control pedestal, was found in the forward (OFF) position, and the elevator gust lock latch was found not engaged.

---------------------------------------------------------------------------------------------------------------------------------------

So . . .
The Gust Lock handle was in the OFF position
Nothing restricted the movement of the throttles to the TO position.
But the FDR data says the elevator was in the locked position.
The Gulfstream engineers maybe can answer how this might happen.
The NTSB folks can maybe find enough pieces to see how “it” happened, what broke.

Any thoughts on why the late reject?
Is rejected TO an exercise done in training?
An engine fire/failure at Vr is normal in training on multi-engined aircraft in my experience.
What about something at V1 -1?
Do you have a long wait time for the brakes to cool on the Gulfstream if you do a rejected TO?
Any reason why one would really like to avoid a rejected TO in this airplane?

The rejected TO decision is a pilot thing, not an engineer thing.
The clearance to TO is also a clearance to reject that TO.

This airplane did not take on Fuel at BED so it would have been light for TO, and acceleration would have been impressive.

Anyone here done a reject in this airplane?

areobat

1st Jul 2014, 17:39

I noted the discussion on the wetlands beyond the runway. I live little over a mile from Hanscom and very close to the Shawsheen river itself, and it is true that the local authorities would never allow the kind of infrastructure changes that would be needed to truly make a different from that point of view.

I find it interesting after reading about the damage that can happen if the hydraulic pressure comes up with the gust lock on, that Gulf didn't fit an engine start inhibit (while locked) as part of the gust lock system.

VFD

1st Jul 2014, 23:10

If they HAD started and taxied with the Gust Lock inadvertently engaged (contrary to the checklist) and then only noticed it that had been accidentally left on and so then released it while hydraulic power was on the flight controls (again contrary to the AFM) is there any chance that the Gust Lock throttle pin could/would release and not the mechanism that locks the flight contols?

This is where I was early on.
Could applying hydraulic pressure to the flight controls with the Gust Lock engaged applied enough pressure to the elevator that the latch would not release. Then along with the impacts of the accident along inadvertent control inputs from the accident along with loss of hydraulic pressure cause the latch disengage?

VFD

Brian Abraham

2nd Jul 2014, 00:59

If they HAD started and taxied with the Gust Lock inadvertently engaged (contrary to the checklist) and then only noticed it that had been accidentally left on and so then released it while hydraulic power was on the flight controls (again contrary to the AFM) is there any chance that the Gust Lock throttle pin could/would release and not the mechanism that locks the flight contols?I did read a comment by a pilot who flies the type that an engine start with the gust lock engaged would require shutdown, disengage the lock, and restart. Wasn't clear if that was required procedure (AFM), company SOP, or personal opinion. He was commenting on this accident, and sorry can't supply a link, may have been AIN or Avweb.

Astra driver

2nd Jul 2014, 03:33

If the engines are started on a legacy Gulfstream (GV models and earlier) with the control lock engaged, it cannot be disengaged without removing Hydraulic power from the controls. The correct way to do this is to shut down the engines and allow the hydraulic pressure to bleed off.

An alternative, non AFM approved method would be to pull the flight power shut off handle which would remove hydraulic power from the flight controls without having to shut down the engines and enable the gust lock to be released.

The big caveat with pulling the flight power shut off handle is that it is only guaranteed to remove hydraulic power from the controls, putting the flight power shut off handle back to its' normal position does not guarantee hydraulic power will be restored to the flight controls.

jdkirkk

2nd Jul 2014, 03:35

JRBarrett has numerous excellent write-ups in this forum on this accident and he knows the systems. The conclusion of this write-up, and this is a partial, would satisfy many of my questions, the primary one being why did they wait too long to reject the TO. I also wonder if this mechanical failure would have left the impression they did not do a control check. And if they did a control check would it have seemed normal?

#152 JRBarrett 14 June

“From a psychological perspective, I would think that if the yoke was locked, or mechanically jammed in such a way that the yoke could not be pulled back - that the pilot's instinctive reaction would have been to instantly recognize that a serious problem existed, and to have initiated an abort immediately.

Instead, all indications are that the abort was only initiated many seconds after VR, which seems to point to the possibility that the yoke came back normally, and the problem was not recognized until the nose failed to rise as would be expected in a typical rotation, consuming many precious seconds, and many hundreds of feet of remaining runway.

If so, this would point to a failure in the mechanical control path between yoke and elevator in which the elevator did not respond to movement of the yoke.... but in such a way that the yoke travel was not restricted. A broken control cable would be my first thought - but there are other possibilities.”

jdkirkk

2nd Jul 2014, 15:08

Quote

Astra driver#126(Astra ran some numbers; this is a partial quote)

Add these two numbers together, 4,400ft to go and 5,400 to stop and you get 9,800ft total.

Total distance from the start of the runway to the gully is approximately 8,900ft
(7,011 ft + 1,000ft overrun + ~890 ft to the gully)

Not saying that there weren't any other failures during the abort, just that a considerable overrun was a certainty with an abort started that far past V1 even with everything working perfectly.

---------------------------------------------------------------------------------------------------------------------------------------

It could be that “something” came unglued in the connection between the yoke and the elevator, but everything seemed normal in the cockpit, including the flight control check, when the controls in the cockpit moved normally. The ailerons and the rudder work - and feel - fine.

The “something” could have also interrupted the sense to the recorder that is leaving details on tape.

The ailerons feel fine on TO roll, and you can feel that through the yoke. It’s calm and so is the rudder.

At V1 it’s normal.

At Vr you pull the yoke back for rotation and nothing happens.

One or two seconds later . . .

You think “TRIM”, and try that, but that doesn’t work.

A shout – “something’s wrong” – and reject, but it’s already too late.

It would be interesting to know how long it took with max power, if that is what they were using, to accelerate to the speed where they started the reject.

CL300

3rd Jul 2014, 08:31

Astra driver

Join Date: Oct 2004
Location: Los Angeles
Age: 51
Posts: 192
If the engines are started on a legacy Gulfstream (GV models and earlier) with the control lock engaged, it cannot be disengaged without removing Hydraulic power from the controls. The correct way to do this is to shut down the engines and allow the hydraulic pressure to bleed off.

An alternative, non AFM approved method would be to pull the flight power shut off handle which would remove hydraulic power from the flight controls without having to shut down the engines and enable the gust lock to be released.

The big caveat with pulling the flight power shut off handle is that it is only guaranteed to remove hydraulic power from the controls, putting the flight power shut off handle back to its' normal position does not guarantee hydraulic power will be restored to the flight controls.

This is more likely the scenario...They knew the plane, but not that well ( or forgot), remember a "way around sort of..from training " did it ...failed.. If they did their "control check", full and free, and nothing was powered down route, nor the surfaces would move nor the FDR would have picked up the signal...consistent with the forensics..

glendalegoon

3rd Jul 2014, 12:27

I remember a scenario which played out a Chicago Midway on an airliner (think a 737). At V1/R the plane didn't rotate. Turned out the plane had been loaded improperly and the W&B trim setting was not proper. Pilot managed to get the plane into the air safely but by the skin of his teeth.

After that we were instructed to give some heft to the yoke to make sure the plane was responsive, well before V1.

This was quite awhile ago (maybe last century). And I can't remember too much about it.

I also remember an incident in which a plane made a hard landing punching the gear through the wings . Turned out another bad W&B and the plane was 20,000 lbs over the weight used to calculate Vref.

There is something about the feel of a plane that can save your life.

galaxy flyer

3rd Jul 2014, 15:16

CL300,

Why is it not "guaranteed" to restore flight control power when the switch is retirned to normal? Seems hard to believe that the switch works in one direction, but might not in the opposite.

GF

mutt

3rd Jul 2014, 16:59

https://farm6.staticflickr.com/5591/14379815497_8f4558bc18_b.jpg

https://farm3.staticflickr.com/2903/14565432722_8c8eb800f7_z.jpg

https://farm4.staticflickr.com/3886/14379678810_a34b9f4d78_z.jpg

The Flight Power Shut Off is shown in the first diagram as a shut off valve, so one would assume that once it is reopened, normal fluid flow to the flight controls would be resumed.

We practice approach and landing with the flight power shut off ON during recurrent, all flight controls work, but just need a lot more muscle.

You may also notice that the Gust Lock isn't powered by ANY hydraulic system, it is purely mechanical.

Astra driver

12th Jul 2014, 02:43

GF,
Quote,
"Why is it not "guaranteed" to restore flight control power when the switch is retirned to normal? Seems hard to believe that the switch works in one direction, but might not in the opposite."

The flight power shut off handle is designed to be used when directed by the AFM or QRH to enable the aircraft to be flown in direct "Manual Reversion", in other words with no hydraulic boost to the controls in the event of a variety of possible flight control malfunctions. The important thing to remember here is that Gulfstream only designed it to be used in the event of an in-flight abnormality or emergency.

The handle should restore all hydraulic power when it is pushed back down, but there is no guarantee that it will do that. It is a misconception among some crews (Perhaps from repeated use in sim training) that the handle is an "On/off" switch, it was never designed as such and is only expected to be a one time use feature in real world operations.

jdkirkk

14th Jul 2014, 16:35

There seems no word has been received from the NTSB other than the first official report on June13.
The only casual word I have read about this accident was a quote from a John Goglia who apparently was with the NTSB at one time and who decided the pilot “didn’t run the checklist, so it immediately makes him a suspect for being a problem.”
This was a day or two after the accident and was not all that unusual; the “experts” always seem to start out blaming the pilot, and that is many times the only thing remembered by the general public.
I suspect that something broke, and did not become obvious until the nose didn’t come up at Vr.
I wonder if the NTSB would immediately tell the manufacturer what they have discovered just in case a problem might exist in other aircraft? Do they always wait for the Final Report to publish details of the accident?

mutt

14th Jul 2014, 20:01

jdkirkk..... have a look at code7700.com they have a very nice explanation of the gust lock system, you might enjoy it.

jdkirkk

15th Jul 2014, 12:30

Thanks, Mutt.
I haven’t done a walkaround on this airplane.
I don’t know how easy it would be to check those springs at night in winter in Fairbanks when you’re tired, but someone in this forum mentioned in a very strong manner the “60 knot elevator free” check, and said it in a manner learned in the sim, maybe the hard way.

There was mention of some discussion of “controls” on the voice recorder. I now wonder if that was about that 60 knot check.

And I wonder if every pilot on every TO in this airplane does this 60 knot check? And is prepared to reject if the check isn’t right?

And all of this is speculation . . .

“. . . you should always follow your primary guidance (Aircraft manuals, government regulations, etc)

jdkirkk

17th Jul 2014, 04:31

http://code7700.com/ (http://code7700.com/)

Thanks to Mutt and Eddie Haskel . . .

Required reading.

dogsridewith

17th Jul 2014, 13:46

Is there interlock mechanism so that when throttles are beyond 5% power the gust lock handle cannot be moved to the surfaces-locked position? (Is it impossible to engage the gust lock during the take off run?)

MotCap

17th Jul 2014, 21:26

"dogsridewith"

In normal operations it is NOT possible to engage the control locks with the engines running and producing hydraulic pressure to the flight control systems.

Your question begs a interesting thought that, would it be possible, with engines running and then pulling the "Flight Power Shutoff" handle, thereby removing hydraulic pressure from the flight controls, could it be possible to then engage the flight control lock? That question I cannot answer. Flight Power Shutoff was always taught to be used, in-flight, in the event of of a flight control malfunction(hard over or jammed; un commanded spoiler deployment).

It would be difficult to believe that a professional crew would not notice that before takeoff the flight controls were in the manual mode(not hydraulically boosted) or locked; but then again........

Thank you for your question.

MotCap

inontime

18th Jul 2014, 12:41

My take as a long time Gulfstream driver. Reasons for a non rotatable G-IV.

Mechanically:

- Gust lock engaged and throttle pin broken. If the flight control shut off was pulled to stow the gust lock, the controls would be VERY heavy and by the time the gust lock was stowed flight control shutoff restored the airplane could have accelerated and the heavy control feel may have precipitated a high speed abort. I have been "told" that it is possible to cancel the control locks in the G-IV with both engines running without pulling the flight control shutoff because both sides of the hydraulics are at 3,000 psi. This is not so in the G-2 or 3 with both engines running because hyd pressures are 3,000 psi combined and 1,500 psi flight system.

- Trim full forward and at Vr could not be re-trimmed in the runway remaining.

- Flaps 10 instead of 20. I operated a Stage 3 G-3 which required a 10 flap TO for compliance. The VRef increased about 5 knots and TO roll about 500 ft but the second segment climb was much improved. This is about the same numbers for the G-IV and should not have been a factor except the programmed data would not match aircraft configuration so the speeds would not box (validate).

- Stall barrier failed in the "push" or stall recovery mode (has happened in the past). This condition would allow the control yoke to move from full forward to about the neutral position giving the appearance of normal elevator control. This can be overcome by depressing the disconnect button on the control yoke. This may also explain why the abort speed was so high. The pilot may have experienced a "push" and could not rotate, depressed the disconnect button and the "push" goes away. He then attempts to rotate (accelerating the whole time) releases the button for normal operation and the "push" comes back. Then attempts a high speed abort.

- Our G-IV experienced a full down auto pilot command in flight and the disconnect button did not over ride the system. A very astute pilot in the right seat (not me) looked up to his overhead CB panel and pulled the appropriate CB and the down command went away. Maintenance checked the systems and computers and found no problems. This excellent pilot informed the other crews rotating into the airplane and when the same down command happened again the next crew knew where and what CB to pull. The CB remained out until the computer was replaced. If the down command could not be cancelled, we surmise there would have been an accident. So if this scenario happened during a takeoff roll there would be no time to look and pull the CB.

- As far as adding the accelerate/go and the accelerate/stop distances, that is not how that works. Both of those distances start from start of the takeoff roll. It will take so long to apply takeoff power continue to V1 and go, as from the application of takeoff power to V1 and then stop. Not added together!

Operationally:

- The abort should have been recognized at V1 and aborted. If the abort was recognized at Vr the Accelerate/Stop would be slightly higher. Still, they should have had enough runway to stop.

- At Vr recognized a rejected TO condition, pushed a button, pulled a lever, cancelled a system that gave the impression they could continue the TO but could not then attempted to stop without adequate runway remaining.

- TRs in or out, a rejected TO, accelerate/stop distance does not include TR in the calculation. They had adequate distance with the TRs retracted.

- The flight control systems in the G-IV are mechanical, hydraulically boosted. In the case of a hard over or unmovable flight control, we then pull the flight control shutoff and go into what they call manual reversion. Very heavy controls but flyable. At no time do any of the flight controls disconnect from the yoke or rudders mechanically.

- As far as a high speed abort, the crew showed great skill staying on the centerline of the runway.

My take but I was not there so all of this is a moot point for them. My condolences to the crew and families. The only positive thing to come out of this will be the knowledge gained and future accidents to be avoided.

MotCap

18th Jul 2014, 21:37

A whole jet career you are trained to either abort by V1 or "go" after V1. If the aircraft doesn't rotate at Vr you still have to abort.

What the heck is the accelerate stop distance from V1 + 45 knots? Obviously more than 9,000 feet.

Feathered

20th Jul 2014, 03:41

inontime (http://www.pprune.org/members/358399-inontime),

Great insights, thank you. Reading between the lines of the investigators' comments so far, I suspect that NTSB has collected enough evidence from the wreckage + flight recorders that they know exactly what happened and there will be no mystery once of the report is published (hopefully it will occur later this year).

I do wonder if a flight control check would have revealed a problem prior to the airplane entering the runway. The taxi out would have been very short, probably only a few minutes of very busy cockpit time occurred between the start of taxi and the take off roll. Although during the day Hanscom is a zoo, at 2100 on a Saturday night it would have been super quiet. They likely had a takeoff clearance well before reaching the Pine Hill hangars adjacent to taxiway Mike.

jdkirkk

20th Jul 2014, 05:35

http://www.rapp.org/archives/2012/11/gulfstream-g650-accident/ (http://www.rapp.org/archives/2012/11/gulfstream-g650-accident/)

The above was an interesting read referred to in this forum about an area of aviation not many line pilots, in my experience, dwell on, or about, unless it shows up in their training.

Grumman/Gulfstream has been building outstanding airplanes for many years, not an easy task.

I’m guessing these three things would have been part of every sim check on a GIV.
“Flight crews are reminded to perform the following as set forth in the applicable AFM procedures for each model aircraft: ensure the gust lock is OFF prior to starting engines (not applicable for G650); check flight controls for freedom and correct movement prior to taxi/takeoff; [and] confirm the elevators are free during the takeoff roll,” said the letter from the manufacturer . . .

The voice recorder indicates the airplane did not rotate at VR as commanded; that caused the accident - something was broken, something did not work as it always had before.

It will be interesting to see what the Feds come up with, where they allocate blame, and what other pilots can learn from this tragedy.

PastTense

1st Aug 2015, 23:56

The manufacturer of the jet that crashed on takeoff in Massachusetts (http://abcnews.go.com/topics/news/massachusetts.htm) last year, killing the co-owner of The Philadelphia Inquirer and six other people, has reported a problem with a fail-safe system that can allow the planes to reach high speeds on the runway even if they are prevented from taking off.
Gulfstream Aerospace Corp. said in a document released by the National Transportation Safety Board (http://abcnews.go.com/topics/news/us/national-transportation-safety-board.htm) that the Gulfstream IV has an interlock system that is supposed to keep the plane's throttle from being moved past 6 degrees, thereby limiting acceleration, while hinged tail sections, called elevators, are immobilized.
But the company told the National Transportation Safety Board last spring that the interlock system actually allows the throttle to be moved to an average 21 degrees. The company said the issue "remained undiscovered on more than 500 aircraft over 25 years and more than 2 million takeoffs."
Still, Gulfstream contends the crash was due to the flight crew's failure to check if the gust lock system, which locks the tail sections, was engaged and to immediately abort the flight once it was clear there was a problem.
Company, FAA Working on Gulfstream IV Jet Fail-Safe Problem - ABC News (http://abcnews.go.com/US/wireStory/company-faa-working-gulfstream-iv-jet-fail-safe-32827970)

Feathered

9th Sep 2015, 20:38

Today, NTSB found the probable cause for the Gulfstream tragedy at KBED on 31 May 2014. As expected, the cause was due to the gust luck being engaged during the attempted take off and the successful application of take off thrust despite the gust lock engaged.

The NTSB video (below) reveals that the crew identified a warning associated with limited rudder control as they entered the runway, a detection of less than normal thrust allowed at the beginning of the departure roll, and an attempt to remove hydraulic power, including to the spoilers for a significant portion of the roll, while runway available passed by.

The NTSB video is quite enlightening, and there will be much more released on this accident, including the performance of the safety interlock.

I tried to put this post on the original 2014 thread, but could not find it on the mobile site.

youtube.com/watch?v=GokKYNOcp20&t=127

loucipo

10th Sep 2015, 17:21

The Phila. Enquirer reported today that part of the Safety Board findings was that the pilots did not perform all their pre-flight checks 98% of the time during the past several years. So IMO it was almost inevitable that something like this would occur. Being a non-pilot, I was amazed at that fact; I could understand sometimes being in a rush and not doing what you are supposed to do, but 98% of the time? Amazing is all I can say.

JammedStab

18th Dec 2016, 07:05

There was a story written on this accident recently. I found some of the comments interesting and will post them here. Some have been edited to remove extraneous info. They may or may not be correct.

"My understanding is that the gust lock/FPSOV engages a hydraulic cut-off valve to the primary flight controls, and/or a thrust interlock preventing max thrust. The safety analysis for that system must be a darn good read, as those are both catastrophic failure items.
Not entirely the pilots fault - some complacency contributed for sure, but the gust lock system sounds flawed.
Knowing that, if I was a G450 pilot I would be doing a full-and-free exterior flight control check pre-takeoff everytime, and where-ever possible I would simply never engage the gust lock - pay extra to have the aircraft hangared!
From 7700 dot com;
1.Check the two gust lock springs below the elevator assembly in the aft equipment compartment during every exterior preflight inspection. (Some crews do not preflight the aft equipment compartment at all; this is not smart.)
2.Ensure the gust lock is off prior to engine start. (This is in the manual and tends to be self-correcting: the throttles will not move unless the throttle lock is broken.)
3.Accomplish a complete flight control check after every engine start. (Some crews skip this routinely; this is not smart.)
4.Accomplish an elevator free check at 60 knots during takeoff. (Some crews skip this or have invented alternate procedures which could actually make things worse. Not smart!)
5.Engage the gust lock when leaving the aircraft without hydraulic power and test each axis and the throttles to ensure it is working.
There is an undocumented technique among undisciplined GIV pilots to use the FPSOV to remove hydraulic power from the flight controls after engine start in case they forgot to disengage the gust lock. I've never seen this done but am assured it works. This technique is not correct and could damage the airplane. The correct procedure would be to shut down the engines, disengage the gust lock, and restart the engines. Whether it works in the chocks after engine start or not, it cannot work with any kind of air loads on the elevator. If the relative wind is pushing up on the elevator, the gust lock hook will have pressure loads that the gust lock handle cannot overcome.

----------------------------------------------------------------------------------------------
There is nothing wrong with the Gust Lock System on a Gulfstream. The Gulfstream GIV uses the same Gust Lock System that is installed in the GII and GIII. There is a BIG RED Handle that is pulled up, it is approx 10" long with the words Gust Lock in white on the handle right next to the Throttles. The Flight Power Shut Off Valve (FPSOV) is not associated with the Gust Lock at all. The foolish crew, instead of aborting while they had time/runway, decided to force the takeoff by unloading the Hydraulic System in "hopes" that it would allow the Gust Lock to be disengaged.
What the NTSB doesn't discuss, or at least put much emphasis is that the same flight crew set the gust lock. The fix for this is really easy . . . FOLLOW the Checklist . . . and perform a flight control check in the chocks.
--------------------------------------------------------------------------------------------------

I used to fly GIV-SP's and G450's in South America, a few years ago. Among the most significant airplanes I flew along my whole career (i.e. B737's, Airbus A310 / A300-600, Fokker 100, Learjet 60 etc), Gulfstreams were by far the most impressive, by all means. A very challenging and high-workload routine, though, with all those functional checks. On the first flight of the day - for the sake of expediting the departure as the big boss arrived (most of the times late), as well as not missing the ATC slots -, we used to break the cockpit preparation in two or three phases, but always quickly-reviewing the previous one(s) while performing the next, in order not to affect operational safety. It is a complex corporate airplane, full of "bad-a** triggers" and demands extra attention, in many senses.
----------------------------------------------------------------------------------------------

Ask any Gulfstream pilot what the weak point on the aircraft is and they will tell you it is the gust lock. Once you start the engines you can't disengage the gust lock without shutting down.
-------------------------------------------------------------------------------------------------

One issue is that the manufacturer's normal checklists include too many items that are really maintence checks or should be performed only on the first flight of the day. The manufacturer includes all those checks not for operational considerations of safety but to protect them, the manufacturer, from liability should an accident occur. There's no reason why a before start checklist should have so many items that it takes an experienced crew thirty minutes to start the engines and possibly another twenty minutes to get to the hold short line. This is what leads flight crews to start shortening the checklists because they see no reason to perform those checks on every leg. Once you begin to omit checks it's easy to skip an important one such as the flight controls.
I've operated and maintained Gulfstream's for over 30 years: GII, GIII, GIV, G450, G550. The gustlock system on the GIV provides a throttle interlock, which restricts throttle movement. Here are the facts: the pilots had a rudder limit message on the EICAS before takeoff. They discussed this, during taxi. That alone should have been reason to stop and investigate.
They started the takeoff roll, engaged autothrottles, but clearly did not observe that the engines were not making take off power, and then realizing the gustlock was engaged, tried to disarm the gustlock while rolling, rather than shut down power and do it. By then, the airload on the elevators provided enough force on the gustlock mechanism that it would not release.
So, is it the aircraft/manufacturer's fault? I think not. The crew had multiple warnings facing them, yet blindly continued.
The one thing the manufacturer is on the hook for: the gustlock system was never actually operationally certified, according to the NTSB report. Because it had been used on past models, it was certified by way of drawing And design review. This factor lead to the amount of power you could achieve with the gustlock engaged on the GIV being inconsistent across the fleet, and several GIV's tested post accident showed that more power than specified could be achieved on some aircraft.
It's important to note however, that the crash aircraft did not achieve anywhere near takeoff power. I suspect that the aircraft, being very light for the takeoff and short trip, also contributed to masking the fact that acceleration was less than should be expected. Again though, an experienced crew should have picked up on this.
You cannot blame anyone but the crew in this case however: the chain of events that lead up to the crash was glaring. Particularly at the point where they realized the gust lock was on, and still continued the takeoff!

galaxy flyer

28th Dec 2016, 19:57

Can you provide a link, JammedStab?

GF

Empty Cruise

29th Dec 2016, 22:06

PLovett

30th Dec 2016, 04:22

Don't leave Empty Cruise because you are absolutely correct. If this crew had survived they should have been prosecuted - they were criminally negligent. Earlier this year I prepared a presentation for the company I work for highlighting the dangers of "Normalisation of Deviance" which despite its name has nothing to do with kinky behaviour but is really one of the biggest killers in aviation. This crash was a prime example of that and it formed a large part of my presentation.

FlyMD

30th Dec 2016, 05:28

As a counter-argument, I would submit that human brains are a lot harder to change than aircraft systems and procedures. So while you are correct with all your points, the fact remains that we have to put warm bodies into seats, and as pilots of today are neither treated, paid or trained like astronauts, we will always get a certain percentage of colleagues who are prone to sub-standard behavior.

It's safe to say that all attempts to assess, motivate, select and ramp-check these people out of the cockpit have failed up to now...

So, one of the more productive ways of improving the overall safety record is to improve systems, interfaces, cockpit ergonomics, procedures and checklists so that even the "worst" pilots tend not to screw it up with fatal consequences.

In order to do that, the kind of "post-mortem" analysis we have seen on this thread ultimately delivers the clues needed to improve the system.

That being said, of course the idiot-proof system does not exist, and probably never will. Of course we all need to be more vigilant towards the normalization of deviation. And we also need to be less tolerant towards colleagues who underperform.

As we were heading to Dubai a couple months back, I was remarking to my sim-partner that it had been quite a few year since I'd approached a recurrent check with trepidation, much less the fear of failing to meet the required standard. Now, I'm not that good, so it can only mean that maybe some of the hurdles we are required to jump over these days are a bit low... I'd be interested to hear some of your opinions on that.

formulaben

31st Dec 2016, 00:45

What surprises me on this thread is the amount of energy being spent on understanding the gust lock system - compared to the amount of energy spent on understanding and working out a solution to habitual non-compliance...

Others are entitled to their opinion, but in my mind, it was not GLs design of the gust-lock system (inelegant and inefficient as it may be) that killed them boys. Them boys were killed by crew that lost respect for what they were doing. We all do mistakes - but this was no mistake. This wasn't 'pilot error'.

You answered your own question there, no? Had this been an actual incident of pilot error myself and I'm sure many others would be far more interested by this accident, and also making an effort to learn from it. The complete lack of any form of checklist discipline and the lack of basic airmanship (dare I say negligence; 3 abort scenarios on this takeoff roll) is what leads professionals to dismiss this for what it is: a complete lack of respect for the aircraft, an embarrassing show of non-compliance and arrogance. It is undoubtdely an anomaly to "professional" aviation.

I go out of my way to read every Part 25 accident and I put myself in the pilots shoes and ask what I would have done...NO WAY do I get anywhere near the threshold without completing the requisite checklists. NO WAY do I initiate a takeoff roll with a primary control issue. NO WAY do I continue a takeoff without required N1/EPR of the day. This was an embarrassing display of "airmanship." I take no enjoyment in saying this, but it was simply amateur hour on that fateful night. As you mention, if there is a discussion to be had, it is how in the world does someone get so complacent?! I find it unfathomable...