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-   -   Gear does not retract - Emergency turn? (https://www.pprune.org/tech-log/532301-gear-does-not-retract-emergency-turn.html)

dirtyrat 20th Jan 2014 09:00

Gear does not retract - Emergency turn?
 
Sorry if this is a stupid question, but I have been wondering about this for a few weeks.
Situation: IFR obviously.
After take off, you move the handle up, but the gear does not retract. All engines are operating normally though.

For the initial course of action, do you:
1. Continue SID normally (Can you make the required gradient?)
2. Emergency turn (There is one published as you are towards high-ish terrain)
3. Other

Would you automatically reach for the "downlock release" button to try and raise the gear?

Fire away... I have a thick skin, and already know I am a rubbish pilot!
Cheers. :ok:

bucket_and_spade 20th Jan 2014 09:13

Ha!

Was thinking about this a little while ago - my gut instinct says play it by ear depending on the airfield. Our charts have minimum VS rates to make the gradient for the SID written in a table so I guess if you can make that VS at the specified speed, you're good on the SID and can continue to fly it as you sort your life out (or the other guy does!). If in doubt, no harm in being conservative and flying the e-turn though I guess.

I'd be hesitant to start punching buttons straight away unless things looked dire (unlikely in this scenario) - methodical, coordinated QRH/ECAM actions definitely better.

From one decidedly average pilot to a self-confessed rubbish one!

Edited to say - full power available too if not already in use of course!

FE Hoppy 20th Jan 2014 09:23

All engines operating is the key. If you can make PDG (almost certainly) just follow the SID. Of course if it's a protracted SID you may not wish to do that as you're probably not continuing with the gear down.

As for using the override button. I would only do it OEI when obstacle limited. You don't know why it won't come up and you don't know what damage it will do if you force it. There are a few incidents of override leading to not getting the gear down at the other end!

TopBunk 20th Jan 2014 09:24

I was always led to believe that gear down performance equates approximately to OEI, and that therefore one should probably carry out any ET procedure.

I wouldn't touch the gear lever override button until some greater emergency developed so as to avoid any unnecessary complications by raising the gear.

By carrying out the ET procedure, you build in some performance reserves in case anything else goes wrong.

Just my 2p ....

Mach E Avelli 20th Jan 2014 09:29

Not knowing the performance capability with the gear hanging out in the breeze, if it won't retract fully, I would be inclined to go with the OEI escape procedure.

Some types have an over ride to bypass the squat switches, and if this is the cause of the failure to retract, it is probably reasonable to use that function - though I would consult the QRH first.

The worst case is when one or more gear legs unlock but don't retract - obviously not a squat switch malfunction but something potentially more serious. In this situation as for whether to attempt to recycle the gear, that's probably type specific. Generalising, again not knowing your type or QRH, I suggest the safest course would be to select it down again and return for landing, or if you need to burn fuel and have confirmed that the gear down performance meets en route criteria, carry on to another more suitable airport.

The party poopers may then say "but wotif you now have an engine failure?". To which I would suggest that we don't assume double failures - if we did no twin and I suspect not many four engine types would be allowed to fly!

Good Business Sense 20th Jan 2014 09:54

Not a stupid question at all - the armchair simulator is one of the best devices in aviation.

Had it happen (widebody) a couple of times - although lots of wheels and doors hanging out there performance should be better than engine out. No emergency turns should be needed - don't forget there is padding in all PANS OPS/TERPS procedures but once you go off road !!!! .... if concerned don't forget to use ATC and their radar if available. Also remember the greatest drag from the gear is when it is in transition - you might want to wait until above MSA to run checklists.

In the MELs of some aircraft you can get some information on gear down performance after take-off - these procedures are used when brakes are locked out etc. It usually gives you a weight penalty and from that you can get a good idea of the climb performance gear down.

You might also ask the cabin crew if they heard anything etc - it might not help too much to know there was a big bang on rotate but it might give you part of the jigsaw.

If the gear just won't come up and you've got all three greens be in the mind set that you don't want to make a drama out of a crisis so take your time and very carefully follow the checklist. You don't want to damage the gear and end up with a red.... when you had three greens to start with.

Remember, resist the temptation to go into the normal clean up attitude - observe the max gear speed as you climb - in my situations I levelled above the terrain at around 15,000 feet to deal with the problem all the while continuing to destination.

If you do get the gear up - who knows what might happen at the other end whether you decide to return or if you continue to destination. Lower the gear much earlier and of course, there is a gear down go around to consider.

The biggest shock that I got first time was the effect on the fuel - even on a short one hour sector at standard uplifts you might have a problem continuing to destination. In both of my situations I had the gear up and tucked away by about 20,000 feet (15 minutes ?) and I really struggled to continue to destination one hour away. It really did eat the fuel.

No egg sucking tutorial intended

bubbers44 20th Jan 2014 14:07

I had it happen in a 4 engine corporate Jetstar one day on a 45 minute flight from LAS to Burbank. I checked altitude and speed restrictions and continued because it only added about 20 minutes to the flight and we had a full load of Japanese business people on board.

It was a bit noisy and one of them came to the cockpit with a puzzled look. I told him the gear would not come up and if we returned it could take all day to get it fixed probably so didn't want to delay them.

Desert185 20th Jan 2014 14:13

The gear has never retracted on my Cessna. I just don't fool with it anymore. Less maintenance expense with fixed gear, anyway.:ok:

Aluminium shuffler 20th Jan 2014 16:11

I very much doubt the performance penalty is even close to engine-out performance, but it could be a problem on a RTOW take off in terrain. Under those circumstances, following any emergency turn procedure may be prudent or even necessary. I think it's what I'd do. On a take off without terrain issues, though, or one well under RTOW, I'd follow the SID. I think it's one of those things where you need to (quickly) weigh the circumstances of the event rather than have a rigid rule.

FE Hoppy 20th Jan 2014 16:16

Here is one of two incidents on the 170 where the crew INCORRECTLY used the override to get the gear up.
Untitled Page

LEAVE IT DOWN!!

con-pilot 20th Jan 2014 16:57


LEAVE IT DOWN!!
I agree, if the gear is down and locked, will not retract for unknown reasons, you have a safe landing gear, at that point. If you do not screw around with it, it will remain safe.

So leave it down and locked, then land when able, where able.

repulo 20th Jan 2014 18:12

Just look at the FPV if available. Multiply the angle by two and subtract roughly 10%, thats your actual climb gradient. All engines operating with gear down should be well above 10% in a jet.

TopBunk 20th Jan 2014 18:49


I think it's one of those things where you need to (quickly) weigh the circumstances of the event rather than have a rigid rule.
I think you are wrong ... I think you, as a captain, need a strategy in advance to execute (and brief) should it happen, so as to avoid a surprised reaction from your colleague.

None of these grey area 'how close to RTOW are we', 'what is the viz like today', 'what is the fpv giving us, less 10%' type calulations at a critical time serves anyone well.

At the end of the day, who cares if you divert/don't reach destination as long as all survive the event. The job is not about making decisions that 'may' work out ok, it is about making decisions that 'will' work out ok and being clear of blame in any investigation in this litigious era. If in any doubt, apply the OEI procedures, don't gamble!

Having said all that, the Captain's decision is final ... so long as he can justify it .... and that responsibility/accountability comes with the fourth stripe

Mach E Avelli 21st Jan 2014 06:11

I am with the alloy fiddler on this. We mere mortal Captains can't have a plan for every contingency on every flight. Sure, we review engine out procedures, missed approaches etc, but hey, do we brief for total electrical failure just after take-off, or full spoiler deployment at 100 feet on final approach? I think not, but if it happened (as both have to me) you'd better be ready to improvise.

Tu.114 21st Jan 2014 07:39

The Dash 8 has a little peculiarity in this case. Over the Copilots seat, there is a flap door that hides the manual main LG release handle. Opening it will disconnect the hydraulic pressure from the main LG. So if it has been opened for any reason, for example during maintenance, and not properly closed again (a few degrees are rumoured to suffice here), the main LG will not retract on selection. The copilot is supposed to check proper closure of the door during his preflight, but every once in a few years, this is overlooked, as things happen.

A quick and easy remedy will be a quick slap (applied to the door!); more often than not this will result in the landing gear resuming its normal operation.

dirtyrat 21st Jan 2014 13:14

May I thank everyone for their input!
Appreciate your time to reply. Great stuff. :ok:

Max Angle 22nd Jan 2014 09:32

Quite agree with the above, the climb performance with the gear down, certainly in a twin, will be way above engine out rates. The only thing I would add is that it would pay to keep the speed back if it happens to you, the drag from the gear will increase massively if you let the aircraft accelerate towards clean speed or beyond, stick close to V2 till you think you are out of trouble.

hifly787 22nd Jan 2014 10:38

To Add
Keeping the gear down intentionally for brake cooling (after quick turn arounds ) . Is it non SOP even if you factored in climb gradient /obstacles etc .

underfire 22nd Jan 2014 11:57

I see many responses regarding OEI, and OEI escape procedures.
First and foremost, there are very, very few SID that have an OEI route deifned.

Second, many posts assume that wheels down somehow equates to OEI performance. I would think that unless you know, that assumption coud be eventful.
Performance by aircraft, and each aircraft variant can be remarkably different.

Why risk it, hit the emergency turn, then sort it out.

mustafagander 22nd Jan 2014 16:27

Recalling basic performance theory, I'd continue on the SID and, as previous posters have said, keep speed back until above LSALT.

I think there would be plenty of performance with all engines - climb performance is all about excess thrust and since T/O is predicated on OEI, there will be heaps of excess thrust with all operating.


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