B737 Gear Lever Jammed Up Plus Eng Failure
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B737 Gear Lever Jammed Up Plus Eng Failure
I'm surprised our sim weirdos in our company haven't thought about this scenario yet:
GEAR LEVER JAMMED IN THE UP POSITION after a go-around.
You depressurize sys. A, it takes time, fuel is short, drop the gear manually,and when at last you're on final, engine 1 fails!
In the arousal of the moment some of our guys might even miss the fact that the gear has raised again, and land without shoes...
Now, my poit is: wouldn't it be wise, after that GEAR LEVER JAMMED IN THE UP POSITION cklist, pull the two LANDING GEAR TRANSFER VALVES c/b?
Landing with the lever up is not natural in an airplane... even if you have depressurized sys.A.
In case engine 1 fails, the Landing Gear Transfer Valve would not raise the gear with sys.B.
Opinions?
GEAR LEVER JAMMED IN THE UP POSITION after a go-around.
You depressurize sys. A, it takes time, fuel is short, drop the gear manually,and when at last you're on final, engine 1 fails!
In the arousal of the moment some of our guys might even miss the fact that the gear has raised again, and land without shoes...
Now, my poit is: wouldn't it be wise, after that GEAR LEVER JAMMED IN THE UP POSITION cklist, pull the two LANDING GEAR TRANSFER VALVES c/b?
Landing with the lever up is not natural in an airplane... even if you have depressurized sys.A.
In case engine 1 fails, the Landing Gear Transfer Valve would not raise the gear with sys.B.
Opinions?
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LEM,
Thanks, I just found it in my old -300 QRH. I had forgotten about that one.
I think due to Manual gear ext. system design change in the NG, it is no longer required. Once you open the Man. Gear Ext. door, the ldg gear selector valve bypass valve connects the gear hyd to the return system disabling the gear retraction i.e the NG Man. Ext. can be done with the gear lever in any position, however the Classic requires it to be in the OFF posn.
Maybe someone can describe it further??
An interesting Sim scenario though! I must give it a try next time I'm in the lurching cave.
Cheers,
Con
Thanks, I just found it in my old -300 QRH. I had forgotten about that one.
I think due to Manual gear ext. system design change in the NG, it is no longer required. Once you open the Man. Gear Ext. door, the ldg gear selector valve bypass valve connects the gear hyd to the return system disabling the gear retraction i.e the NG Man. Ext. can be done with the gear lever in any position, however the Classic requires it to be in the OFF posn.
Maybe someone can describe it further??
An interesting Sim scenario though! I must give it a try next time I'm in the lurching cave.
Cheers,
Con
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the landing gear lever jammed in the up position NNC states that you can extend manually the landing gear after having depressurized Sys A even with the lever in the up position. After that if the landing gear is down and locked you can land, with 3 green and 3 red.
X LEM : nice
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On the classic,if the ldg gear lever is stuck in up position it won't be possible to manually extend the gear due to positive pressure being locked in the ldg gear system.In order to allow the gear to 'fall' you'll have to get rid of this pressure,which is done by depressurizing system A and removing pressure locked by using speed brakes.
After those manouvres you'll be able do disengage the mechanical locks (using manual release handles) and the gear will fall under gravity.
In normal use, positioning the ldg gear lever to off depressurize the gear hyd system,allowing it to fall when manually released.
On the NG ,opening the man gear extension door bypases the ldg gear lever,allowing the locked pressure to escape from gear sys,thus permitting manual release.
Nice point you're making LEM,but consider the other scenario: same like yours,but you have to go around after engine failure..
..
The worst scenario is engine failure-gear down right after take-off or go around, if you check climb gradients you'll see what i'm talking about.
So,in your case,i'd rather go-around,and do the same thing again followed by a SE long stabilized approach.
Brgds Alex
After those manouvres you'll be able do disengage the mechanical locks (using manual release handles) and the gear will fall under gravity.
In normal use, positioning the ldg gear lever to off depressurize the gear hyd system,allowing it to fall when manually released.
On the NG ,opening the man gear extension door bypases the ldg gear lever,allowing the locked pressure to escape from gear sys,thus permitting manual release.
Nice point you're making LEM,but consider the other scenario: same like yours,but you have to go around after engine failure..
..The worst scenario is engine failure-gear down right after take-off or go around, if you check climb gradients you'll see what i'm talking about.
So,in your case,i'd rather go-around,and do the same thing again followed by a SE long stabilized approach.
Brgds Alex
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Why not?
Now, my poit is: wouldn't it be wise, after that GEAR LEVER JAMMED IN THE UP POSITION cklist, pull the two LANDING GEAR TRANSFER VALVES c/b?
Why not? You can do anything to be save you can deviate from all procedures. The point is, that you have to be prepared for it. I can`t imagine, that this will happen to somebody in real and they will think about LANDING GEAR TRANSFER VALVES c/b. We have a lot of time to think about it now but it such a situation...
Why not? You can do anything to be save you can deviate from all procedures. The point is, that you have to be prepared for it. I can`t imagine, that this will happen to somebody in real and they will think about LANDING GEAR TRANSFER VALVES c/b. We have a lot of time to think about it now but it such a situation...
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Respectfully, you don't need a new checklist item, you need some trainers who recognise that multiple failures are statistically irrelevant and a waste of sim time... Sadly, it's still all too common, and FOI seem not to care...
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Gday I-2021,
You are quite correct.
My point however was that to do a "normal" Man gear ext in the 300 the gear lever needs to be in the off posn to allow the gear to fall out. If it is jammed in the UP posn the system pressure must be bled off as Alex described, not so in the NG as opening the Man Gear Ext door does it for you.
Kit d',
Couldn't agree more. Its a waste of $1000 an hour in my view.
Cheers,
Con
You are quite correct.
My point however was that to do a "normal" Man gear ext in the 300 the gear lever needs to be in the off posn to allow the gear to fall out. If it is jammed in the UP posn the system pressure must be bled off as Alex described, not so in the NG as opening the Man Gear Ext door does it for you.
Kit d',
Couldn't agree more. Its a waste of $1000 an hour in my view.
Cheers,
Con
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multiple failures are statistically irrelevant and a waste of sim time
I can see an argument if the user is paying personally .. however, with an appropriate attitude all round there is much pilot development value in putting together the more unusual and higher workload scenario ...
I can see an argument if the user is paying personally .. however, with an appropriate attitude all round there is much pilot development value in putting together the more unusual and higher workload scenario ...
wouldn't it be wise, after that GEAR LEVER JAMMED IN THE UP POSITION cklist, pull the two LANDING GEAR TRANSFER VALVES c/b?
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multiple failures are statistically irrelevant and a waste of sim time
I can see an argument if the user is paying personally .. however, with an appropriate attitude all round there is much pilot development value in putting together the more unusual and higher workload scenario ...
I can see an argument if the user is paying personally .. however, with an appropriate attitude all round there is much pilot development value in putting together the more unusual and higher workload scenario ...
Yes, it can be very interesting to do 'old-fashioned' sim exercises - I was in the box not long ago with an experienced TRE colleague, we were being 'checked' by a company for whom we might have done some flying, but, in the end, did not. It was one of those silly details with mutliple failures, which we worked our way through with good humour. It delievered no training value at all.
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When automation works against you
Just a few points before the main thing:
- If we are on final and have an engine flameout, depending on the height and distance and other factors, we usually increase immediately the speed, retract to Flaps15, GPWS override, and probably continue for landing, if not too destabilized.
Also the go around is an option, but consider the scenario: this happens after having already performed a go around, the QRH procedure is long, fuel is short... if not destabilized, landig as described above would be a good option to consider.
- multiple failures scenarios: here our "inventors" love them, they dream all night to create subsequent failure, like IRS faul on n°1, then TRF bus 2 off (after 5 minutes IRS 2 quits...) plus all sort of hydraulics, fuel leak etc...!
NOT boring at all, I can tell you, and sometimes you must really squeeze your last drop of energy to survive that...
Back to main topic:
As I already said, landing an airplane with the lever up is not natural, even if your gear is down after sys A depressurization.
Sometimes automatic systems can work agaisnt you, as a good instructor made me learn the hard way once, when during a go around with engine severe damage, the autothrottle retarded the damn lever to idle (it had engaged in the retard mode, and I should have disconnected it)...
After the QRH procedure GEAR LEVER JAMMED IN THE UP POSITION, you are landing with a potential disaster waiting to happen, although remotely possible.
Imagine engine 1 fails during the flare, or there is a glitch in the signal, or you loose engine 1 rpm signal during the flare, the gear would retract!
I think it would be wise to pull those two LGTV breakers (which are right at shoulder level on P6, above the bar which protects the breakers against FO seat).
This idea came to my mind when I was told by a FO of his sim ck, when, after this long QRH procedure, they had to go around, and instead of keeping the gear down, they forgot and retracted it, so they had to start all over again before the next landing.
Automatic reactions of mechanical systems are nice, but beware of unwanted activations!
LEM
- If we are on final and have an engine flameout, depending on the height and distance and other factors, we usually increase immediately the speed, retract to Flaps15, GPWS override, and probably continue for landing, if not too destabilized.
Also the go around is an option, but consider the scenario: this happens after having already performed a go around, the QRH procedure is long, fuel is short... if not destabilized, landig as described above would be a good option to consider.
- multiple failures scenarios: here our "inventors" love them, they dream all night to create subsequent failure, like IRS faul on n°1, then TRF bus 2 off (after 5 minutes IRS 2 quits...) plus all sort of hydraulics, fuel leak etc...!
NOT boring at all, I can tell you, and sometimes you must really squeeze your last drop of energy to survive that...
Back to main topic:
As I already said, landing an airplane with the lever up is not natural, even if your gear is down after sys A depressurization.
Sometimes automatic systems can work agaisnt you, as a good instructor made me learn the hard way once, when during a go around with engine severe damage, the autothrottle retarded the damn lever to idle (it had engaged in the retard mode, and I should have disconnected it)...
After the QRH procedure GEAR LEVER JAMMED IN THE UP POSITION, you are landing with a potential disaster waiting to happen, although remotely possible.
Imagine engine 1 fails during the flare, or there is a glitch in the signal, or you loose engine 1 rpm signal during the flare, the gear would retract!
I think it would be wise to pull those two LGTV breakers (which are right at shoulder level on P6, above the bar which protects the breakers against FO seat).
This idea came to my mind when I was told by a FO of his sim ck, when, after this long QRH procedure, they had to go around, and instead of keeping the gear down, they forgot and retracted it, so they had to start all over again before the next landing.
Automatic reactions of mechanical systems are nice, but beware of unwanted activations!
LEM
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Hi LEM,
When you perform the Landing Checklist after the LG Jammed In The Up Position Cklist, you must place the gear lever "Down" as stated in the Checklist. The Landing Checklist calls for "Landing Gear.... DOWN, 3 Green". Nothing will happen if engine N°1 fails.
When you perform the Landing Checklist after the LG Jammed In The Up Position Cklist, you must place the gear lever "Down" as stated in the Checklist. The Landing Checklist calls for "Landing Gear.... DOWN, 3 Green". Nothing will happen if engine N°1 fails.
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LEM
So after completion of the QRH and you have to make a go around or get an engine failure on final approach, the gear will raise again ?
Please explain as its new to me !
Zenj
So after completion of the QRH and you have to make a go around or get an engine failure on final approach, the gear will raise again ?
Please explain as its new to me !
Zenj
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Zenj ,failure of eng 1 (N2 indication bellow certain level ) with landing gear lever up will activate the LGTU ,raising the gear with sys B hydraulic volume.
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In the arousal of the moment some of our guys might even miss the fact that the gear has raised again, and land without shoes...
I have nothing in my notes that would shed any light on this situation that could be better than your very smart (however unscripted) CB pull.
With HYD A failure, we know after a manual gear extension that normal retraction is not possible on the classic unless you cycle down then up.
An interesting question is raised with your proposed scenario, LEM. I would love to see what would shake out in the sim on this one.
