TM 1-1520-240-10
9-1-2
nals will be used to notify occupants of an emergency
situation:
1. Prepare for ditching, or crash landing 3
short rings.
2. Water contact Sustained ring.
Safety equipment, emergency exits, and entrance routes
are shown in Figures 9-1-1 and 9-1-2. Emergency exit
door handles are yellow and black striped. Safety equip-
ment consists of seven first aid kits, three hand fire extin-
guishers, one emergency escape axe, and three emer-
gency exit lights.
9-1-5. After-Emergency Action.
After a malfunction of equipment has occurred, appropriate
emergency actions have been taken, and the helicopter is
on the ground, an entry must be made in the Remarks
Section of DA Form 2408-13-1.
9-1-6. Engine.
9-1-7. Flight Characteristics.
a. If an engine failure occurs, no control problems
exist unless power from the remaining engine is not suffi-
cient to maintain the selected RRPM. If sufficient power
is not available to maintain altitude, descend to an alti-
tude where single-engine (S/E) flight can be accom-
plished (fig. 9-1-3 and 9-1-4 for S/E performance data).
The best indications of engine failure are decreased
torque on the failed engine and a compensating increase
in torque on the remaining engine, accompanied by a
droop in RRPM, and a continuing decrease in N1 speed
below 60 percent. An engine failure will have no effect on
any of the helicopter systems as long as the RRPM is
maintained above the minimum speed. On the 714A a
1% to 3% RRPM momentary transient can be anticipa-
ted. Then RRPM will automatically recover to the se-
lected RRPM. 714A Single engine failure is character-
ized by an engine fail caution light, change in engine
noise, split in torque, momentary drop in the RRPM with
the DECU recovering RRPM to 100% within maximum
single engine torque limits.
b.
712
When one engine fails, rotor speed can be
expected to drop to as low as 93 percent. Safe RRPM
can usually be regained by using engine beep trim and
power available of the operating engine.
c. If sufficient power is not available, normal RRPM
is regained by lowering the thrust control. Procedure to
be followed after engine failure will be governed by the
altitude and airspeed available for helicopter control and
for maintaining sufficient RRPM for continued flight and
landing. The height-velocity diagram (fig. 9-1-4 and
9-1-6) present the airspeeds and wheel heights from
which a safe landing can be made at various GW and
temperatures following a S/E failure.
d. Decrease in thrust after engine failure will vary with
altitude and airspeed at the time of occurence. For
example, thrust must not be decreased when an engine or
engines fail at a hover in-ground effect (HIGE): whereas,
during cruiseflight conditions, altitude and airspeed are
sufficient for a significant reduction in thrust, thereby
allowing rotor speed to be maintained in the safe operating
range. Following an engine failure, cyclic control isadjusted
as necessary to remain in hover over the desired point or
to control airspeed and flight path in forward flight. Pedal
pressure is applied as necessary to control aircraft
heading.
e. Airspeed should be maintained at the opti-
mum for existing conditions for continued flight (S/E
failure) or for autorotational descent (dual-engine
failure). As airspeed increases above 70 KIAS in
autorotation, there is a corresponding increase in rate
of descent (R/D). Airspeed up to 100 KIAS or Vne,
whichever is slower, will increase glide distance but
should be avoided at low altitude because the time
available to decelerate is critical. At airspeeds below
70 KIAS. R/D in autorotation increases and glide
distance decreases. Gliding the helicopter in autorota-
tion out-of-trim will also increase R/D and decrease
glide distance.
9-1-8. Minimum Rate of Descent Power Off.
The power off minimum R/D is attained at an indicated
airspeed of approximately 70 knots and 100% RRPM
(fig. 9-1-7).
9-1-9. Maximum Glide Distance Power Off.
The maximum glide distance is attained at an indicated
airspeed of 100 knots or Vne, whichever is slower, and
100% RRPM (fig. 9-1-7).