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Gulfstream IV in Bedford MA

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Gulfstream IV in Bedford MA

Old 5th Jun 2014, 18:38
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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.

Last edited by susier; 5th Jun 2014 at 18:51.
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Old 5th Jun 2014, 18:41
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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.
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Old 5th Jun 2014, 18:56
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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.
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Old 5th Jun 2014, 21:47
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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! ;-)
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Old 5th Jun 2014, 22:29
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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.
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Old 5th Jun 2014, 23:01
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There's no way going to full flaps will help get the aircraft airborne.
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Old 5th Jun 2014, 23:05
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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.
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Old 5th Jun 2014, 23:28
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"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.
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Old 5th Jun 2014, 23:31
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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.
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Old 6th Jun 2014, 04:10
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Almost imposable to be out of CG, and same for having control lock. It's a guarentee that these were not the issue.
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Old 6th Jun 2014, 05:03
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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 ?
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Old 6th Jun 2014, 05:14
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but its david katz.... maybe they didnt like him as much as dick evertal
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Old 6th Jun 2014, 05:41
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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
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Old 6th Jun 2014, 06:50
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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)

this is 243 people alive, and therefore limited headlines in newspapers...a bit like engines inflight shutdowns...barely leaving the quality report database...
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Old 6th Jun 2014, 07:05
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EMAS Save at ORD [Archive] - PPRuNe Forums


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.
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Old 6th Jun 2014, 08:17
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it says that to date the fastest was 80kt, but there is no limitation as per se..AFAIK
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Old 6th Jun 2014, 12:10
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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.
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Old 6th Jun 2014, 12:45
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Control Lock

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.

Last edited by Old Boeing Driver; 6th Jun 2014 at 12:46. Reason: Spelling
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Old 6th Jun 2014, 13:31
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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.
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Old 6th Jun 2014, 14:31
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One thing out of this accident is that the gully at the end of the runway needs filling.
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