TM 55-1510-220-10
NOTE
The
ILS
localizer
and
glideslope
warning flags indicate insufficient
signal strength to the receiver. Certain
electrical
mechanical
malfunctions
between the receiver and indicators
may
result
in
erroneous
localizer/glideslope
information
without
a
warning
flag.
It
is
recommended that ILS information be
crosschecked
with
other
flight
instruments prior to and during final
approach. Utilization of NAV TEST
prior to the final approach fix may
detect
certain
malfunctions
not
indicated by the warning flags.
Section IV. FLIGHT CHARACTERISTICS
8-61. STALLS.
A prestall warning in the form of very light buffeting
can be felt when a stall is approached. An aural warning
is provided by a warning horn. The warning horn starts
sounding approximately five to ten knots above stall
speed with the aircraft in any configuration. If correct stall
recovery technique is used, very little altitude will be lost
during the stall recovery. For the purpose of this section,
the term "power-on" shall mean that both engines and
propellers of the aircraft are operating normally and power
is set at approximately 50%. The term "power-off" shall
mean that both engines are operating at idle power.
Landing gear position has no effect on stall speed. During
practice, enter power-off stalls from normal glides. Enter
power-on stalls by smoothly increasing pitch attitude to
decrease airspeed by approximately one knot per second
until stall occurs.
a.
Power-On Stalls. The power-on stall attitude is
very steep and unless this high-pitch attitude is
maintained, the aircraft will generally "settle" or "mush"
instead of stall. It is difficult to stall the aircraft
inadvertently in any normal maneuver. A light buffet
precedes most stalls, and the first indication of
approaching stall is generally a decrease in control
effectiveness, accompanied by a "chirping" tone from the
stall warning horn. The stall itself is characterized by a
rolling tendency if the aircraft is allowed to yaw. The
proper use of rudder will prevent the tendency to roll. A
slight pitching tendency will develop if the aircraft is held
in the stall, resulting in the nose dropping sharply, then
pitching up toward the horizon; this cycle is repeated until
recovery is made. Control is regained very quickly with
little altitude loss, providing the nose is not lowered
excessively. Begin recovery with forward movement of
the control wheel and a gradual return to level flight. The
roll tendency caused by yaw is more pronounced in
power-on stalls, as is the pitching tendency; however,
both are easily controlled after the initial entry. Power-on
stall characteristics are not greatly affected by wing flap
position, except that stalling speed is reduced in
proportion to the degree of wing flap extension.
b.
Power-Off
Stalls.
The rolling tendency is
considerably less pronounced in power-off stalls (in any
configuration) and is more easily prevented or corrected
by adequate rudder and aileron control, respectively. The
nose will generally drop straight through with some
tendency to pitch up again if recovery is not made
immediately. With wing flaps down, there is little or no
rolling tendency and stalling speed is much slower than
with wing flaps up. The Stall Speed Chart (fig. 8-2)
shows the indicated power-off stall speeds with aircraft in
various configurations. Altitude loss during a full stall will
be approximately 800 feet.
c.
Accelerated Stalls. The aircraft gives noticeable
stall warning in the form of buffeting when the stall
occurs. The stall warning and buffet can be demonstrated
in turns by applying excessive back pressure on the
control wheel.
8-62. SPINS.
Intentional spins are prohibited. If a spin is inadvertently
entered use the following recovery procedure:
8-26
