TM 1-1520-238-10
Change 10
9-11
9.6 DELETED.
9.7 ENGINE RESTART DURING FLIGHT.
After an engine failure in flight, an engine restart may be
attempted. A failed engine should not be restarted un-
less it can be determined that it is reasonably safe to do
so.
9.8 ENGINE EMERGENCY START (DECU
INSTALLED ONLY
)
CAUTION
Engine overspeed and overtempera-
ture protection are not provided
when the ENG 1 or ENG 2 (as ap-
propriate) circuit breaker is out.
The T700-GE-701C engine exhibits
inconsistent starting capability
above 6000 feet density altitude.
Starts above this density altitude
may be unsuccessful and require
“over temperature” abort by the pi-
lot.
The following emergency start may be attempted if the
hot start preventer will not permit a normal engine start
and starting is necessary because of a tactical emer-
gency situation.
1. ENG 1 or ENG 2 (engine to be started) circuit
breaker – OUT.
2. Start engine using normal starting procedure.
3. ENG 1 or ENG 2 circuit breaker – IN, prior
to advancing PWR lever – FLY.
9.9 ROTORS, TRANSMISSIONS, AND DRIVE
SYSTEM FAILURES AND MALFUNCTIONS.
9.9.1 Tail Rotor Malfunctions.
WARNING
Pilot situational awareness and correct
analysis of the helicopters condition
and operational environment are criti-
cal in the successful accomplishment
of these procedures. The low inertia ro-
tor system, coupled with high rates of
descent during vertical autorotations,
may not provide the pilot with ade-
quate reaction time and cushioning
pitch. Activation of the CHOP collar or
retarding the PWR levers prior to re-
duction of the collective will result in
rapid decay of rotor RPM. Successful
completion of an out-of-ground-effect
hovering autorotation is doubtful.
These procedures represent a best estimate of helicop-
ter reactions and crewmember procedures. The most
critical consideration in responding to any tail rotor mal-
function is that the crewmember correctly interprets the
nature and extent of the problem.
NOTE
Tail wheel should be locked during all
landings.
9.9.2 Loss of Tail Rotor Thrust.
CAUTION
If engine chop is used to minimize
main rotor torque, increasing collec-
tive pitch without first retarding PWR
levers to IDLE may cause an uncom-
manded yaw.
Loss of tail rotor thrust occurs when there is a break in
the drive system; for example, a severed drive shaft.
The nose of the helicopter will turn to the right. If the
helicopter is in forward flight, there will be a right roll of
the fuselage along the longitudinal axis, and the nose of
the helicopter may pitch downward. Normal pilot input to
compensate for the right roll will produce a left side-slip.
This downward pitch will be more pronounced if a
tail rotor component
has separated from the he-
licopter. In some case, depending on the severity
of the right rotation, powered flight to a
