On Thursday, October 4, 2012 8:02:37 AM UTC-4, jams wrote:

I have amassed quite a bit of info on the subject now, some interesting

technical stuff that suggests that you cannot overstress a well designed

sailplane at Va no matter what you do.


This is a common misconception, and was cited as contributing to the American Airlines flight 587 crash of an A300. I know there will be differences between the transport category vs. glider and US vs. European standards. However, be aware that Va may only give you protection for one full deflection of a control surface on one axis. If you make alternating applications on one axis or apply large deflections on more than one axis simultaneously, you can defeat the structure even at a speed below Va. Here is the FAA summary written after AAL587.

SUMMARY: The Federal Aviation Administration amends the airworthiness standards applicable to transport category airplanes to clarify that flying at or below the design maneuvering speed does not allow a pilot to make multiple large control inputs in one airplane axis or single full control inputs in more than one airplane axis at a time without endangering the airplane's structure. The FAA is issuing this final rule to prevent pilots from misunderstanding the meaning of an airplane's maneuvering speed, which could cause or contribute to a future accident.

http://en.wikipedia.org/wiki/America...nes_Flight_587

http://www.ntsb.gov/doclib/reports/2004/AAR0404.pdf

http://en.wikipedia.org/wiki/Maneuvering_speed


Glenn Fisher