On Sat, 09 Oct 2004 00:04:33 GMT, Bob Moore
wrote in ::

Quoted from Aerodynamics for Naval Aviators:

"The loads imposed on an aircraft in flight are the result of
maneuvers and gusts."

There's some information on the subject he
http://ecfr.gpoaccess.gov/cgi/t/text...3.70.8&idno=14
§ 23.333 Flight envelope
(c) Gust envelope. (1) The airplane is assumed to be subjected to
symmetrical vertical gusts in level flight. The resulting limit load
factors must correspond to the conditions determined as follows:

(i) Positive (up) and negative (down) gusts of 50 f.p.s. at VC must be
considered at altitudes between sea level and 20,000 feet. The gust
velocity may be reduced linearly from 50 f.p.s. at 20,000 feet to 25
f.p.s. at 50,000 feet.

(ii) Positive and negative gusts of 25 f.p.s. at VD must be considered
at altitudes between sea level and 20,000 feet. The gust velocity may
be reduced linearly from 25 f.p.s. at 20,000 feet to 12.5 f.p.s. at
50,000 feet.