I A P 2 0 2 3 . 0 0 1 - A F M / I R I S T E X A N I I P A G E | 209
FOR SIMULATION USE ONLY – NOT A TRAINING AID
will quickly dissipate kinetic energy and may place high stresses on the aircraft
structure. At low airspeed, the inertial forces on the aircraft exceed the authority of
the aerodynamic controls, rendering the controls mostly ineffective until flying
speed is regained.
The post stall gyration can be aggravated or extended through continued application
of pro-stall controls or by misapplication of stall recovery controls. Post stall
gyrations may be violent and disorienting.
The intuitive response of rapidly applying controls in all axes in an attempt to arrest
the motions is generally ineffective and may actually increase the motions, as the
flight controls may no longer act in the normal sense.
Neutralizing controls and reducing the power to IDLE is the best response until
motions stop and the controls become effective in the normal sense again.
Incipient Spins
The spin-like motion that occurs between a post stall gyration and a fully developed
spin is called an incipient spin.
Any stall can progress to an incipient spin if steps are not taken to recover the
aircraft at either the stall or post stall gyration, or if pro-spin controls are
maintained.
In an incipient spin, the motions appear to be “spin-like” and there is a sustained
unsteady yaw rotation, but the aerodynamic and inertial forces are not yet in
balance.
As a result, an incipient spin is characterized by oscillations in pitch, roll, and yaw
attitudes and rates. The nose attitude will fluctuate from the horizon to vertical
(nose down), the yaw rate will increase toward the steady-state spin value, and the
wings will rock about the steady-state spin value.
An incipient spin can be identified by an oscillatory spin-like motion, a fully
deflected turn needle, a stalled angle of attack, and airspeed that is accelerating or
decelerating toward the steady-state value.
Visual indications may be misleading and can lead to the false impression of a
steady-state spin. The incipient spin phase of the aircraft lasts approximately 2
turns.
This may be prolonged during intentional spin entries by failure to apply proper
pro-spin controls, potentially leading to a spiral.
To Next Page
Loading...