Flap extension before clear signal from ground crew?
 

Many airlines extend flaps before they start taxiing. Some airlines have a procedure that requires them to wait with flaps extension until clear signal is given by the ground crew. Can any of you guys expand a bit on this? Why can't the crew extend flaps anytime after engine start without waiting for clear signal? Are there any routine situations where there may be equipment under the wing after engine start?

Yes -

1) You never know whether the crew may be under the aircraft checking something before releasing it. Leading edge devices can bite nastily.

2) There is push-back equipment that hugs a mainwheel to move the aircraft and it is best not to lower flap while it is attached.

3) If you do not get the 'ok' you are not going anywhere anyway:)

In any case, there is no panic to lower flap - why not wait?

Agree with above, but our SOPs call for flaps to be lowered by PNF in the "flow" being triggered by PF ending the engine start...ie (in most cases) as we are pushing back...

Suggest you get your SOP changed before damage to personnel/equipment occurs.

Yea, thats the problem! Even if I agree, I can´t do my own little thing and wait with my flow just because I feel like it, it would be very difficult to operate a two man crew if each and everyone had their own little SOP´s...

hello,
the decision to extend flaps will depend on:-
1. type of push-back equpment in use. if its of the type attached to the main landing gear then its prudent to wait till one gets the all clear.:)
2. type of a/c...i.e. ground clearance below the wing (B737 as against B747)
3.depends on how the flap/slats are powered. some can be moved only after engine start.hyd-v/s-elec.
So the sops vary according to the combinations.
the factor governing is safe operation:)

Run Over the Ground Crew
 

At my old carrier, we never moved anything until we got the 'all clear' signal. However, that SOP was not always the procedure. A couple of times over the years, the crew, in an effort to be fast (which, to inexperienced crews, "fast" means better and more competent) ran over the ground crew.

So, to preclude injury (to the ground crew...and to the captain when the engineer implanted a spanner into the captain's head), the procedure was established that nothing...absolutely nothing...was done until the 'all clear' signal was received. After that, the after-start flow was commenced and the taxi clearance was requested.

It's difficult to slow these younger guys down a bit. You're saving, literally, only seconds by taking the chance of hurting someone and/or damaging equipment.

Is it worth it?

Tom

I do agree with TOM.my airline sop says the same "wave off grnd crew" then commence the flow. but i have observed many other carriers extending flaps during push-back:ooh:

I can see nothing wrong with the Flaps being lowered or what ever you want to power up, or move during the push, as long as you inform the head set man what you are about to do.
Technically speaking he is in charge on the push back, if he calls brakes on, you apply the brakes, not 40 seconds later when you have wondered what the hell does he want them on now for.
It's the same if he calls out cut the start or shut down on an engine, he can see what you can not, so learn to trust the guy's wearing the electric hat and may be they will trust you not to run them over.:ok:

I are a captain now, but, back in the days when I was a ramp rat, I used to get pissed when the pilots extended the flaps during pushback because it just obstructed my view under the wing! It is nice to see where one is pushing!!

There's 101 good reasons to leave the Flaps alone until 'All Clear' by the ground crew, well alluded to in the previous responses.

Our SOP requires that after "All Clear", that Flaps be set immediately prior to taxy, the intention being to avoid forgetting them during a long taxy. What does concern me, and was the first thought in my mind upon reading the opening post, is that Cold Weather ops require leaving the wing clean until just prior to takeoff, to avoid possible ice accretion in the various flap assemblies during taxy.

With "Flaps" now being a part of the 'After Start' checklist on our (B777) ECL, it concerns me that the potential exists, with winter coming, to miss them on the 'Before Takeoff' checklist if the item has been overriden on the 'After Start' checklist. Yup, I know that the checklist should be held until all open items are completed, but one more hole in the Swiss cheese..........

Regards,

Old Smokey

Our procedures are to wait until we get the wave off, call for flaps, than taxi clearence.

We generally wait until we pass the last aircraft in the alley-way until extending flaps. Greatly reduces mishaps.

If we are at a hard stand where push backs are not required, then we wait until we make our initial turn towards the taxiway before we extend flaps.

I'll bet you'd want to wait before lowering flaps on such a plane like the MD-11, where those big boards attached to the trailing edge of the wings MD likes to call flaps tend to stick out quite a bit in takeoff configuration!

Which is why, at my lot, we have a specific Cold Weather ops checklist.

Tom,

You have about said it all on this subject. And, as we all know, if the SOP isn't always the procedure, it darned well better be or someone will get hurt...and someone will stand responsible for it.

The young guys are very easy to slow down...a little "Come to Jesus" meeting will fix that problem.

There is no advantage to getting the flaps out in a hurry; what for ? When all else fails, follow instructions.

Our SOP's said: "After the agent's salute ( the all clear signal ), the FO may extend the flaps...".

And further said ( to address Old Smokey's pertinent remarks ): "If the flaps/slats are left up for certain conditions during taxi, delay completion of the TAXI check until the flaps/slats are in the takeoff position and the flight control check is complete."

It's all really very simple. Prime Directive: do no harm.

How can you say that this is "my own little thing"? I say again, my SOP very clearly states, that the after-start flow begins when the captain selects the APU bleed off.

If the Captain decides that it is prudent and safe to delay that action, then that would seem like the safest choice. And, this is not a departure from the SOP.

TomConard is - again - correct. Too many inexperienced crews believe that "Fast = better and more competent". People with that belief are sadly mistaken.

At anytime in a aircraft - especially on the ground awaiting an "all clear signal" - doing anything in a hurry, is simply demonstrating your lack of experience. You're only kidding yourself if you believe that everyone around you won't notice.

That said, Mr @ Spotty M , you are also correct. During the push-back, the guy on the ground is in control. And, if HE said, "...Captain, extend the flaps...", "...Set the brakes..." or any other reasonable request, that request would be honoured.

Finally, I couldn't agree more than with bafanguy... "It's all really very simple. Prime Directive: do no harm!"

[QUOTE=captain_jeeves]How can you say that this is "my own little thing"? I say again, my SOP very clearly states, that the after-start flow begins when the captain selects the APU bleed off.
QUOTE]

Easy now!! Im saying that EVEN if I AGREE with what was said on the very good reasons for waiting with flap extension, I CANNOT do that AT MY airline because it´s NOT OUR SOP!!
I was NEVER talking about what you should or should´nt do! Ok?
/CP

I was under the impression the 777 had 2 levels of protection against that:

1. Closed loop items on the electronic checklist are colour coded so it's easy o spot an incomplete item.

2. TO config warning when advancing power.

Am I mistaken?