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Gulfstream IV in Bedford MA

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Gulfstream IV in Bedford MA

Old 27th Jun 2014, 13:47
  #201 (permalink)  
 
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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.

FWIW.
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Old 27th Jun 2014, 18:23
  #202 (permalink)  
 
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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 and the rest of New England. As T. F. Green Airport in Warwick, Rhode Island and Manchester-Boston Regional Airport in New Hampshire have become viable alternatives to 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.
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Old 27th Jun 2014, 22:38
  #203 (permalink)  
 
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Originally Posted by Bill Harris
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.
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Old 27th Jun 2014, 23:00
  #204 (permalink)  
 
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Originally Posted by jdkirkk
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?

Last edited by Feathered; 27th Jun 2014 at 23:21.
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Old 28th Jun 2014, 17:44
  #205 (permalink)  
 
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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.
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Old 29th Jun 2014, 18:16
  #206 (permalink)  
 
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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.
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Old 29th Jun 2014, 20:49
  #207 (permalink)  
 
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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.
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Old 29th Jun 2014, 22:28
  #208 (permalink)  
 
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Gulfstream cabin door

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.
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Old 30th Jun 2014, 10:55
  #209 (permalink)  
 
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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?
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Old 30th Jun 2014, 15:01
  #210 (permalink)  
 
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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?
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Old 30th Jun 2014, 20:19
  #211 (permalink)  
 
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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
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Old 30th Jun 2014, 20:42
  #212 (permalink)  
 
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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?
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Old 1st Jul 2014, 09:25
  #213 (permalink)  
 
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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'.

Last edited by ramble on; 1st Jul 2014 at 23:59.
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Old 1st Jul 2014, 16:15
  #214 (permalink)  
 
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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?
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Old 1st Jul 2014, 18:39
  #215 (permalink)  
 
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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.
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Old 2nd Jul 2014, 00:10
  #216 (permalink)  
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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
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Old 2nd Jul 2014, 01:59
  #217 (permalink)  
 
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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.
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Old 2nd Jul 2014, 04:33
  #218 (permalink)  
 
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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.
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Old 2nd Jul 2014, 04:35
  #219 (permalink)  
 
Join Date: Jun 2014
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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.”
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Old 2nd Jul 2014, 16:08
  #220 (permalink)  
 
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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.


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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.
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