I think was part of the point being made, SMOC, the limit is not specific enough to be a limit. The limitation says do not extend flaps, it doesn't say don't fly with flaps extended above 20000'. If that's what they mean (and I'm certain in my own mind they do) then Boeing should write it.

I agree with you that we should not be trying to this, nor should we attempt to be Boeing test pilots, however, in my opinion, the poor English used in the AOM opens Boeing to challenge if someone were to go above 20000' feet with flaps extended and it all went wrong. Semantics, yes, but that's what lawyers love when big industry cocks up.

Pontius, likewise, I guess the world is becoming a place where everything has to be written and common sence has no place, it'll never stop, the next question will be it doesn't say I can't do barrel rolls so can I try? I know extreme the mind boggles when pilots can't think of the "intent" Asia is full of its "not written" shame the Western world is going down the same path.

I'm very impressed by the very low number of users who really understood my question.

How can someone expect a professional and serious answer if so many don't even spend 2 seconds reading and understanding the question.

English is not my native language, maybe I was not so clear in the initial message but I believe I'm not the only one in fault here.

That's obvious that braking a rule (better...braking a limitation) outside an emergency situation is not professional and not even safe.

As those ones, really few, who correctly understood my question said, we are not braking any AFM-FCOM etc Limitation...looking the papers.

I was just trying to find (that's why I asked your help) a document where something clearer was stated because I might have missed it!

Captain 'Hoot' Gibson of TWA 727 fame, is the man to ask about flaps at high altitude. I think it's called, 'the other way to get down'.

Yes

Yes


The limitation is for A/C configuring for high altitude airfields not for use in an abnormal situation.


George :ok: exactly.

This is an anonymous forum. I hope there are a lot of MS Flight Sim pilots here.

By George:

He certaintly is. He would refer you to Boeing and today probably cite the 787 as an example of Boeing's methods.

As a fellow TWA pilot may I add, as I have before, neither the FAA nor the company faulted that crew. The NTSB did because they were in Boeing's pocket at the time.

Now, many years later, the FAA is in Boeing's pocket instead of the NTSB.

breakthesilence:

I read your entire first post the first time.

No one in their right mind, who is actually a real airline pilot, would come even remotely close to doing what you proposed.

Now, go back to your MSFS and have fun.

- to introduce this 'history' into this thread demonstrates a complete lack of understanding of aircraft performance and the topic.

Why not tell us EXACTLY what happened and then everyone will see the irrelevance of the posts. Did he climb above 20k with flaps extended? Did he extend flaps above 20k contrary to the limitation?

Aterpster, please, quote any post where I "proposed" to fly above 20000 feet with flaps extended.

I always respect my colleagues, virtual or real, but at this point I really think I'm not talking with people but actually monkeys; it's unbelievable how you are able to put down expression or ideas one has never expressed!

Before sending me to play Flight Sim, I can send you to play toys in diaper, than you could start learning how to read and maybe in few years you'll be able to write down your name.

I will not fall in the game "I'm a real pilot, I have XXXX Flight Time etc."; I don't have to disclose my CV to anyone to face your invitation to MSFS.

Here is a self quote from post number 5:

Chaps,

Time to retire to the various corners of the ring and count to ten. Saves me the trouble of wielding the big stick ... far prefer rational thought to return to the fray.

The guiding light remains "play the ball, not the player"

j.t.:

The "ball" in this game was the launch question:

Can you climb above 20,000 feet with Flaps extended?

Even as a hypothetical it was beyond the pale.

It was akin to me asking you, "If I lose an engine below Vmcg can I attempt a takeoff anyway?"

Come on...be serious, it's not the same kind of question, above all if you read that I was looking for sections of manuals or something written to support the misleading statement of Boeing's Limitation section of the AFM.

It was curiosity, search for something I was, probably, not able to find.

The concept is clear: it's not a great idea to fly above 20000 feet with flaps extended.

The curiosity: Had Boeing set such a limitation in any manual as I don't know if I'm missing it?

It's really, reaaaaally different from stating that I don't know or, worse, I'm willing to fly that way.

Given the exact phrasing of the original limitation, I think the question was a reasonable one and did not deserve the offhand comments it has received.

There are plenty of aircraft systems which can have multiple limits on some types, like landing gear: one maximum for deployment, one for when it's down and yet another for retraction. Also can be IAS, mach or both.

On the 777, the computers won't let you deploy flap >20K which can be problematic if you have a certain type of static failure and the aeroplane still thinks it's at 30,000' even though you're nearly on the ground.

I'd guess there are sound aerodynamic/structural reasons why it isn't a good idea to fly around at high altitude with flaps/slats out, so Boeing have thought what might be needed for operational reasons (going in/out of Bogata, for instance), added a margin then rounded it up to 20,000'. The text doesn't say what exact configuration, so there would logically be less of a problem with F1 than F30.

It's one of those scenarios that rewards a little previous thought. Like BOAC, I don't regard 20K as a hard "wings stay on/wings come off" limit but would be reticent to exceed this unless it was to avoid something worse, like hitting a mountain or running out of fuel.

The answer to: "Can you climb above 20,000 feet with Flaps extended?" would be yes, of course, but only if you *really* need to. It takes quite a bit of imagination to get to that point but hey, you never know.

Also, "If I lose an engine below Vmcg can I attempt a takeoff anyway?", could be answered by yes as well. Not all attempts will be successful, depending on the exact circumstances! It's not something that's recommended either. ;) (Next time in the sim in a twin, try a single-engined takeoff from stationary - surprising what a non-event it can be...)

This thread is a good example of why I don't really contribute here anymore. Lot's of people with 1000s of post, claiming to be real pilots, who can't even read.

I found your initial question interesting, I don't know the answer either. I feel for you Breakthesilence, load of rubbish replies and insults. I salute you and am impressed that you managed not to sink into their levels. I probably would have, which is why I stay away, because every thread here tends to degenerate :(


As for the scenario, the question is "why do it?":

A 50 min flight is normally not planned much higher than FL300, so how much do you actually expect to gain comparing to flying at FL200? If in your scenario the home base has 3 runways and it's CAVOK, why not simply dip into the alternate fuel and complete the flight in FL200.

The very first reply has the answer as far as I am concerned (737 TRE) . The 20000 restriction is in place because the aircraft has not been flight tested/certified with flap above 20000. Will it fall out of the sky? Probably not, but it is unknown territory, hence the manufacturer's requirement

I once flew as an FO with a CAA inspector in the left hand seat, where this exact question came up. The CAA inspector insisted that the limitation was specific about extending the flap, not operating with flap extended - and we proceeded to FL380 or so with a small amount of flap extended.

(There's more to that story, but that's the guts of it.)

So - yes, it's an old question. Yes, it can be misinterpreted, and yes where it can be misinterpreted there will be a pilot who will do it.

The limitation is standard on every jet aircraft I have flown, and like everyone else, I am convinced that it simply means "Flaps aren't tested in this region - here be dragons".

You flew to FL380 with some Flap extended????????

I'd suggest that with your IAS below VFE your TAS would be way toooooooo fast for the poor old Flaps to not be damaged!!!!

Yikes.....

I said it was a small amount of flap. ;)

... and since when are flap limitations based on TAS? Indeed, what would TAS have to do with flap loads at all? :confused:

I think nitpicker is confusing TAS with performance. If you're at a high TAS low level you're at a high IAS too and almost certainly outside flap operating limits. If you are at a high TAS because of altitude then you're about to change a high speed wing into a lower speed wing. And that's if you're even able to get flaps out (the limitation part of a LOIN check) at high level given your inevitable high IAS ( 240-260 kts on the A320 at FL360+). And yes I know the PFD is actually displaying CAS/EAS.