Sunday, September 2, 2007


The normal stall entered from straight level flight, or an unaccelerated straight climb, will not produce added load factors beyond the 1-G of straight-and-level flight. As the stall occurs, however, this load factor may be reduced toward zero, the factor at which nothing seems to have weight; and the pilot has the feeling of "floating free in space." In the event snapping the elevator control forward effects recovery, negative load factors, those that impose a down load on the wings and raise the pilot from the seat may be produced. During the pull-up following stall recovery, significant load factors sometimes are induced. Inadvertently these may be further increased during excessive diving (and consequently high airspeed) and abrupt pull-ups to level flight. One usually leads to the other, thus increasing the load factor. Abrupt pull-ups at high diving speeds may impose critical loads on airplane structures and may produce recurrent or secondary stalls by increasing the angle of attack to that of stalling.

As a generalization, a recovery from a stall made by diving only to cruising or design maneuvering airspeed, with a gradual pull-up as soon as the airspeed is safely above stalling, can be effected with a load factor not to exceed 2 or 2.5 G's. A higher load factor should never be necessary unless recovery has been effected with the airplane's nose near or beyond the vertical attitude, or at extremely low altitudes to avoid diving into the ground.

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