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Old 15th Jul 2009, 16:19   #21 (permalink)
 
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"Demonstrated Crosswind Component" is NOT a limit unless it is listed in the limitations section of the POH. Since the certification must be flown 'as an average pilot', I have heard from reliable sources that the test pilot is not supposed to make any compensation for the crosswind and just plunks it down. A test of the landing gear strength really if you think about it. With good pilot skills you should be able to handle at least up to the DCC,
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Old 15th Jul 2009, 16:34   #22 (permalink)
 
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Quote:
I can't seem to get a definitive answer to this. What does "Max demonstrated X-wind" actually mean?

Is it:
A) Most crosswind the aircraft has been landed in without kicking off drift (crab technique).
B) Most crosswind the aircraft has been landed in with drift kicked off (crab technique).
C) Most demonstrated using wing down method.
D) None of the above.
As I understand from an old test-pilot friend some years ago.

....Using the maximum crosswind available during the certification phase for the aircraft, and, using the cross-wind landing technique as described in the Aircraft Flight Manual / FCOM.
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Old 15th Jul 2009, 17:06   #23 (permalink)
 
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Quote:
"Demonstrated Crosswind Component" is NOT a limit unless it is listed in the limitations section of the POH.
That is either a tautology or not always true... As far as the manufacturer is concerned, it is not limiting. It may or may not be a limit to any given operation depending on what regulations apply to that operation.
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Old 20th Sep 2011, 22:48   #24 (permalink)

 
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The most x wind at a 90 degree angle that you can be assured of maintaining control-ability of the aircraft during take off and landing.

Certainly this number is well below the test pilot max numbers, given they have to assume a variety of pilot experience and ability, not to mention runway conditions, gusts, weight of aircraft, etc.
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Old 23rd Sep 2011, 01:25   #25 (permalink)
 
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whenrealityhurts re “…you can be assured of maintaining control…”
There is no such assurance in a max demonstrated crosswind; you have no idea how much margin there is from a limit condition – primarily because the manufacturer has not been there.
In addition the test only assumes an ‘average’ pilot, a task which does not require undue skill or strength – experience and ability are not defined. How do pilots judge themselves before a max crosswind landing, how many times have they done it before, and what is their currency? Not known, and often misjudged.
Furthermore, the manufacturer does not have to consider runway conditions, but most do now publish guidance for wet conditions. The manufacturers’ tests may not record the type of runway surface – lateral friction characteristics; this might affect the ability to stay on the runway; as might tyre conditons.
Also, the manufacturer may measure the wind speed with a more sensitive system than used by ATC, thus the ‘tower’ wind might be differ, and in operations the accuracy of wind reporting can be ‘significantly’ different.
Then there are gusts … !
See #10 to #13.
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Old 24th Sep 2011, 17:44   #26 (permalink)

 
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Safetypee - Obviously you don't have a clue on how they determine speeds, maneuvers, braking distances during the flight test process.
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Old 24th Sep 2011, 19:40   #27 (permalink)
 
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wrh

please give a specific example in the post by safetypee where you note an error allowing you to make that statement. I'm curious.

and, by the way, max demonstrated means precisely that - the maximum demonstrated value. no margin, no pad, no "test pilot extra", nada.
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