Gulfstream IV in Bedford MA
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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.
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.
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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.
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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-ne...ng-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?
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-ne...ng-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?
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“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.
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.
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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?
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?
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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.
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.
mutt,
Sorry for the plug here, but the GLF is the Harley of Bizjets.
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jdkirkk..... you answered your own question...
The permitted throttle position is no where near the required position for takeoff.
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.
“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.
properly during the flight control
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.
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Control Locks and Checklists
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?
{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?
Last edited by MotCap; 26th Jun 2014 at 07:50. Reason: typo
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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.
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.
@ galaxy flyer...
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.
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.
@ jdkirkk...
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.
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.
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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 . ..
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 . ..
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Originally Posted by jdkirkk
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.
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.
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.
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A recent news report 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.
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.
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.
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.
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Flight Control Lock
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
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