Gulfstream IV in Bedford MA
 

Boston.com has a story about a Gulfstream running off the end of the runway and burning on a takeoff attempt.

Report: Plane Crashes at Hanscom Airfield - Massachusetts news - Boston.com

Not sure about that, this one crashed pretty much on the rwy centerline, which makes me think that it didn't roll. Also looks like it went quite some distance past the end of the rwy (around 800m).

I hate the thought of discussing the reasons for a crash so soon after the event, but just so susier doesn't take his theory any further, the 650 and IV have different flight control systems.

New Mexico crash - Gulfstream test pilots with bad engineering data rotated at too slow an airspeed, stalled and ...

I haven't seen any good photos yet.

Wondering? again only wondering!


Were the flaps positioned for takeoff?

Were thrust reversers deployed?

Wondering about weight and balance

Wondering about birds

you guys can figure out why I am wondering!

Philadelphia Inquirer's Lewis Katz dies in plane crash

Sounds like the same incident.

glendalegoon, add a aborted take off that did not end well to your list ie aborted to far down the runway etc

yes irish 21

that's part of the thrust reverser question.

so, we have a night takeoff, what could go wrong? and if it did go wrong how did it GO WRONGER if an aborted takeoff was done


if it got airborne even three feet, that plane should have gone fine on one engine. shouldn't have tried to set down again, not that it happened that way.

also wondering if the tires are in good shape. if they are melted, maybe they tried to stop

if they are beautiful, they tried to fly

and if one is flat and the rest beautiful, the sound of a bad tire gets worse after you get airborne

or did a piece of tire get into an engine

or
or
or

even one good photo would help.

How very sad.

2 Flight Crew.
1 Flight Attendant
4 Passengers.

Rest in peace all, and thoughts with family and friends. Very sad indeed.

I finally saw a daylight photo. Seems the cockpit area is relatively intact.

From background, it looks like the plane never got airborne and just went straight off the end of the runway.

unsuccessful aborted takeoff?

anyone remember that lear that lost its braking system because the plane ''thought'' it was airborne? aborted and couldn't use wheel brakes?

This is about the best info on this accident I've seen so far.

Gulfstream IV N121JM crash claims seven lives | Corporate Jet InvestorCorporate Jet Investor

Way too little reliable info to be comparing to other similar accidents at this time so I'll refrain from doing so. With one of the dead being a media outlet owner, I expect the NTSB will make some public statements in the coming days. Stand by for a trickle of investigation related news.

I don't have anything to source but from a friend of mine working on this he indicated that it's being classified as a "runway excursion" initially by investigators. Some of the key possibilities they're looking at based on aircraft positioning and environmental observations are an aborted takeoff, a wildlife strike and a catastrophic failure of aircraft components. Obviously this is the most preliminary information and I only obtained it by casual conversation.

He also pointed out that the initial assessment is subject to change based on new evidence.

The Lear crash you are referring to was a result of pilot error. They had a tire blow-out and the captain attempted to abort their takeoff above V1. (The FO can be heard on the CVR saying, “Go, go go.”) It MIGHT have turned out better had the thrust reversers worked but the tire also took out a squat switch that locked-out the thrust reversers in flight. So they were attempting an abort at 140 kts. with blown-out tires and no reverse thrust.

there are a lot of deer that venture onto the runways in the northeast states at night, mainly for the deer to get away from the bugs, There have been several jet accidents because of deer some on Bedford airport and others. I have flown into many of these airports at night to see deer just standing on taxiways/runways while you are landing. There are many laws/rules that some airport have to keep the fencing low enough for deer to be able to migrate through the airport areas...big debate with pilots & environmentalist.

I could see the same up at Bedford as it is surrounded by woods etc and as you drive through the near by towns they are very wooded = lots of deer.

wonder if there are any owls near there. they fly at night.

I think the Deer theory is a good one, I've been in there many times and seen them.
Maybe it took out the hydraulics failing the brake(s)?

NTSB press conference indicates plane exited runway , hit localizer antenna



from photos the over run is sort of a gully.

a totally flat area would have given a better outcome I think.

did not see any phenolic foam overrun.

SK Jets Info
 

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

ERA12MA122

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."

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

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.

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


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

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

Yes.

Part 91.609

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.

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

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. :)

thrust reversers...
 

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.

Thoughts???

NTSB briefing today
 

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.

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

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

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!

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

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.

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.

Hell of an overrun
http://bostonherald.com/sites/defaul...1bdc33b73a3baf

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

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.

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)

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.

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?