flap extension on 737
Joined: Feb 2007
Posts: 478
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From: -------
It's not important if anyone understand or not, the fact you ask is self explanatory that those kind of comments are out of place. This is supposed to be a professional forum, and this section a technical one, not yours or Defacto chat.
FB
FB
Joined: Jan 2008
Posts: 2,296
Likes: 305
From: All at sea
Actually, 20,000 feet is a common enough certification standard and is likely to be quite arbitrary. If there is no requirement to extend the test parameters beyond that, why go to the expense?
Like the common 8 or 10,000 feet bird impact speed limit with windshield heat inoperative. But AFMs may be written that this limit is 10,000 feet AMSL rather than AGL, so what happens when you are over mountains where eagles fly? Common sense prevails, one would hope......
Like the common 8 or 10,000 feet bird impact speed limit with windshield heat inoperative. But AFMs may be written that this limit is 10,000 feet AMSL rather than AGL, so what happens when you are over mountains where eagles fly? Common sense prevails, one would hope......
Joined: Apr 2010
Posts: 1,320
Likes: 102
From: IRS NAV ONLY
Additionally, certification for use of flaps above FL200 would probably also require determination of flap placard speeds in terms of Mach number (as is the case for landing gear).
In any case, I don't think there is any need for Boeing to certify use of flaps above FL200 on any current jet aircraft.
In any case, I don't think there is any need for Boeing to certify use of flaps above FL200 on any current jet aircraft.
Joined: Feb 2003
Posts: 356
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From: AUS
Rather! It was discovered in earlier testing programs, British not Boeing that large electric motors would arc in less dense atmosphere.
At what altitude will they not arc with the insulating alloys (heavy) that we understand?
Twenty thousand was roughly the figure and development proceeded with this understood baseline.
Thus a limitation became a standard on the drawing board for the design of modern airliners.
Hydraulics, not without their own problems of rubber seals, purity and type of oil and flammability overcame a lot of this of course! Hence speedbrakes and hydraulically controlled control surfaces.
Now! If the aircraft you are flying has a limitation for flap or gear extension, respect it as it is likely that it has only been designed and tested to that parameter.
Some of the earlier posters should pay more attention in class and have the wit to understand that whatever they are now, they are not the finished product. Knowledge grows with time.
At what altitude will they not arc with the insulating alloys (heavy) that we understand?
Twenty thousand was roughly the figure and development proceeded with this understood baseline.
Thus a limitation became a standard on the drawing board for the design of modern airliners.
Hydraulics, not without their own problems of rubber seals, purity and type of oil and flammability overcame a lot of this of course! Hence speedbrakes and hydraulically controlled control surfaces.
Now! If the aircraft you are flying has a limitation for flap or gear extension, respect it as it is likely that it has only been designed and tested to that parameter.
Some of the earlier posters should pay more attention in class and have the wit to understand that whatever they are now, they are not the finished product. Knowledge grows with time.
Joined: Apr 2010
Posts: 0
Likes: 0
From: Home soon
Eh Tapshi...
'Please','thank you' ...are terms that do exist.
All your post are the same (even I admit some are interesting questions) as not a single polite request.As people here owe to answer questions you may have.
Hence the comment on burping and chewing...general education..
Fulblast,I see your comment is quite useful as well
I will take my coat now and get some time off
'Please','thank you' ...are terms that do exist.
All your post are the same (even I admit some are interesting questions) as not a single polite request.As people here owe to answer questions you may have.
Hence the comment on burping and chewing...general education..
Fulblast,I see your comment is quite useful as well
I will take my coat now and get some time off
Last edited by de facto; 8th January 2013 at 12:55.
Joined: Jan 2008
Posts: 2,296
Likes: 305
From: All at sea
Thread drift warning and sorry, but to follow up on de Facto's comment.
Recently I was anchored in my little yacht having a nice afternoon nap.
Next I hear a female voice shouting "hello you MUST help us"
I look out and see these idiots have tried to cut between me and the shore and gone hard aground.
They were in no immediate danger, but she kept yelling "you MUST help us, you come and tow us off" etc.
Even though it was obvious I could hear her, I just kept asking her to repeat. She did not get it until her mate worded her up to use the "please" word. Whereupon I rendered assistance.
So yes, Tapshi, next time please use the P word, and maybe thank those of us who take the time to answer.
Recently I was anchored in my little yacht having a nice afternoon nap.
Next I hear a female voice shouting "hello you MUST help us"
I look out and see these idiots have tried to cut between me and the shore and gone hard aground.
They were in no immediate danger, but she kept yelling "you MUST help us, you come and tow us off" etc.
Even though it was obvious I could hear her, I just kept asking her to repeat. She did not get it until her mate worded her up to use the "please" word. Whereupon I rendered assistance.
So yes, Tapshi, next time please use the P word, and maybe thank those of us who take the time to answer.
Joined: May 2008
Posts: 159
Likes: 9
From: Euroland
This comes out of FCOM chapter 9 - Flight Controls
I find this book to be handy giving a lot of info, although not always with enough detail.
Bart
Code:
To prevent excessive structural loads from increased Mach at higher altitude, flap extension above 20,000 feet should not be attempted.
Bart
Last edited by bArt2; 23rd January 2013 at 08:23.
