733 Gear not locked down QRH query

[the_tyke1]

I see from the QRH that if you have gear not locked down on the 733, you will be going round straight away from (probably) flap 15 and straight into an alternate extension procedure. (unless you have a secondary indication on the OHP and that is OK). Most a/c I've flown recommend a gear recycle before proceeding with an alternate extension, is this a complete NO NO on the 73 ?

[Permanent Standby]

Nothing is a complete NO NO if the commander considers it prudent to do so however, the Flight Crew Training Manual recommends you dont do it in case you cycle the gear up and the other wheels dont come down again!

Hope this helps

[Checkboard]

In aviation, if something is broken, and you are still flying in a controllable state, it is generally a bad idea to attempt to adjust anything - just in case you get yourself into an unflyable state.
The gear is designed to work. If you try to put it down and it doesn't work then you have a failure - in most light aircraft admittedly that is a microswitch problem - but in large aircraft (where you may not feel all of the bumps and crashes) you have to consider a major mechanical malfunction, like a sheared scissor linkage etc.
Retracting the gear with a major mechanical problem could pierce the fuel tanks, hydraulic lines or (gasp!) foul the control cables. If it doesn't go down as advertised, then take what you've got and the rest is for the insurer.

[A Very Civil Pilot]

On 737, if you get a not locked indication, try giving the gear lever a little push in. It may well be that the contacts that illuminate the red lights are not disconnected.

You can see how it works in reverse when you come to raise the gear after takeoff. Pull the gear lever out to unlatch it, and you get 3 reds as well as the 3 greens. Push it back in and the reds go out.

[the_tyke1]

OK, thanks guys.:ok:

[InSoMnIaC]

Permanent Standby the Flight Crew Training Manual recommends you dont do it in case you cycle the gear up and the other wheels dont come down again!

Which FCTM are you referring to?

I don't know which edition you have but the latest one doesn't say anything of the sort.


In fact if the other wheels don't come down again then you have the manual gear extension NNC or even if the lever gets stuck up and won't come down again there is a NNC for that also.

There is nothing in the QRH or FCTM that prohibits you from re cycling the gear before performing the manual gear extension NNC.

[Fair.Pilot]

I do agree. I've yet to come across any notes or manual that prohibit recycle the landing gear lever.

Most of the time is the false indicator of the lights. Usually give the landing lever a "jerk" and there you go..."Three Greens"!
(Same method as mentioned by A Very Civil Pilot)

[fruitloop]

Why not have a geek through the viewing windows ?? Don't all 733 have a nose and main wheel-well window??

[Checkboard]

Only on the older models. The NGs have a second set of gear indicator lights instead of the viewing windows.

[Permanent Standby]

Insomniac - I suggest you read my post again. A 'recommendation' is NOT mandatory, all situation dependant.

[IFixPlanes]

Only on the older models. The NGs have a second set of gear indicator lights instead of the viewing windows.
Not only the NG.
At least Lufthansa has a second gear Indication on the aft overhead panel.

[Driver 242]

Before doing ANYTHING outside what it says in the QRH, remember that Boeing has moved well away from fault finding.
There are many things that can happen with gear rigging problems. I know of one 737 that went into an uncontrollable left turn on gear retraction. The crew put the gear down and regained control. The aileron cable was being fouled.
If there is a problem, stick to the QRH. If you do anything outside it, you open yourself up to a huge can of worms.

[Flap 5]

Driver,

That is nonsense. The QRH would not cover the aileron cable being fouled by the landing gear. That is a classic case of the crew not following the QRH but using their common sense. In that instance having the human in the loop who could think for themselves saved the day.

[relax.jet]

btw

737NG Flight Crew Training Manual, part 8: Non normal operation; p.8.21 October 31, 2004 (revision date of this page); FCT 737NG(TM) says:
"Recycling the landing gear in an attempt to extend the remaining gear is not recommended."

Well, it happened to me ones, we had an unsafe landing indication. And it was only switch in landing gear lever. So as stated above, on 737 you better check (push down on landing gear lever) first and only then ask for QRH.

To save your time

[fogatgatwick]

because when you open the manual gear extension door on the NG, it shuts off hydraulic power to the landing gear (via a microswitch)

on the classic there is no facility to do this except by manually depressurising the A system

[capt.topgun]

absolutely........
and some of our instructors keep the door open when u wanna retract d gear
to FOX/FIX u in the sim !!!!!!!!!!!!!!!

[IFixPlanes]

Pulling the Landing Gear, Altn Extend Sol CB on the P6-3 (D16) will "override" the open manual gear extension door. :E

[CaptainSandL]

Here is the full quote from the current 737 FCTM, Revision 7, 31 Oct 2007.

Partial or Gear Up Landing
Land on all available gear. The landing gear absorbs the initial shock and delays touchdown of airplane body parts. Recycling the landing gear in an attempt to extend the remaining gear is not recommended. A gear up or partial gear landing is preferable to running out of fuel while attempting to solve a gear problem.

IMHO this would be useful information to have in the QRH at the start of the "Partial or gear up landing" procedure. I suppose it could lead to a very thick QRH.

[ohreally]

Flap 5

Regarding the crew not following the checklist. Not being in the QRH is true, but I think you will find that this is an extremely important Boeing bulletin. The crew did absolutely the right thing. Those bulletins are important and need to be read.

But as you say, commonsense if you think about it.

[Flap 5]

Many years ago an A320 on approach into Hong Kong Kai Tak suffered turbulence and had the wing tip brake come on when the flaps were at 'full' (due to negative g). The ECAM emergency instructions told the crew to put the flap lever back to the '3' position as the system assumed an assymetric flap condition. This completely screwed the computer controlled flight controls and a very hairy landing ensued. The ECAM also showed the flaps in an amber fault condition but that they were in the 'full' postion, however the crew religiously followed the ECAM drill.

I was given the same fault on my next simulator check and noticed the flap position at full, albeit in amber, and continued with the flap lever at 'full' to an uneventfull landing. The graphic indication of the flap is a direct feedback of the flap position as opposed to the flap lever which is only a selected position. It was only after that the Training Captain told me it was the same condition as the previous incident.

In fact there had been an OEB (Operational Engineering Bulletin) about it - but these were often obscure and mainly for engineering.

So the moral is use the QRH but if it offends common sense then use that. The QRH (or ECAM) drills can not cover every possibility. It is also why you spend so much time in ground school learning the systems.

[Centaurus]

It is also why you spend so much time in ground school learning the systems.

Well, yes and no. The CBT gives you bare bones information in theory enough to get you through the type rating. Need to know as against nice to know.
The FCOM goes into the systems a little deeper. The real systems experts were the old school chalk and talk engineers who took you through each system in great detail in the classroom.

Whether you actually needed that detailed stuff to safely fly the aeroplane is debatable. But certainly that detailed knowledge could be handy if of course you ever remembered it in the heat of a complicated non-normal. Hence the beauty of the QRH. In the majority of non-normal situations the QRH is the safest way to go and also keeps the lawyers at bay.

[frontlefthamster]

...or hence the ugliness of the Airbus ECAM philosophy and function, in event of what it sees as multiple failures, which aren't, generally concerned with nasty electrical happenings.

Regarding the 737 gear, I have twice persuaded recalcitrant gear to behave by re-cycling the system. I think I recall that re-cycling is advised against on the grounds of the time it takes, not for any good engineering reason. Considering the likely failures that would lead to gear not locking down, I'm not persuaded that any of them could propagate from one gear to another.