Aerodynamic Principles
Out-of-Control Flight
The combination of these factors determines the control requirements necessary to reduce the yaw rate.
A neutrally loaded or slightly fuselage-loaded aircraft with a good tail design (such as the T-2) recovers
easily with rudder opposite to the direction of spin. A high performance aircraft (such as the F-14 and
F-18) does not possess enough rudder effectiveness to reduce yaw rate, and you must provide additional
anti-spin moments for rapid recovery. Deflecting ailerons reduces the autorotation rolling moment and
produces adverse yaw to aid the rudder yawing moment in effecting recovery.
The second requirement for recovery is to reduce your AOA. In most aircraft, neutral elevator will ensure a
reduced AOA once you reduce the yaw rate. In some aircraft, however, you must use forward or aft stick
during the initial phase of recovery to increase the effectiveness of the rudder. Figure 15 depicts the erect
spin recovery controls for several aircraft.
F-18
F-14
EA-6
T-2
T-34
AV-8
T-38
A-4
T-45
Rudder
Against
Against
Against
Against
Against
Neutral
Neutral
Neutral
Aileron
With
With
Forward
Aft
Neutral
Elevator
Neutral
Fwd or Aft
FUSELAGE-LOADED
WING-LOADED
Figure 15: ERECT SPIN RECOVERY CONTROLS
PROGRESSIVE SPINS
A progressive spin occurs when an aircraft enters a second spin immediately following initial recovery from
a spin, with the direction of the rotation normally opposite to that of the original spin. A progressive spin
may result from holding in anti-spin inputs after rotation stops, holding in aft stick during recovery, or
initiating recovery pullout with insufficient airspeed or excessive AOA. The reversal in the rotation may be
quite violent, and the spin may tend to be more nose low with faster rotation than the initial spin.
In all cases, maintain neutral controls, reference the turn needle, AOA, and airspeed, and after ascertain-
ing the flight mode, execute the appropriate recovery procedures.
HIGH-SPEED SPIRALS
You may confuse a high-speed spiral with a spin if you don’t properly analyze the flight instruments.
However, when you reference the instruments, you will immediately recognize that you are not in a spin.
The high-speed spiral is characterized by a nose-low attitude, high roll rates, and
(9-98) Original
Page 21
Previous Page
