HEADQUARTERS OH-58A, Technical Manual

Page: 266 / 292

If aircraft fi re occurs on ground while using
Ground Power Unit (GPU) ; the GPU should be
shutdown immediately.
9-27. HOT START.
During engine starts using a Ground Power Unit
(GPU), failure of the GPU could possibly result
in an engine hot start. After GPU failure during
start, the pilot must turn the battery switch on
before accomplishing the procedure described
below.
During engine starting or shutdown, if TOT limits are
exceeded, or it becomes apparent that TOT limits may
be exceeded.
1. Starter switch – Continue to press and
hold until TOT is less than 200°C.
2. Throttle - Close.
9-28. ENGINE/FUSELAGE/ELECTRICAL FIRE –
GROUND.
EMER SHUTDOWN.
9-29. ENGINE/FUSELAGE FIRE – IN FLIGHT. If a
fi re is observed during fl ight, prevailing circumstances
such as VMC, IMC, night, altitude, and landing areas
available must be considered in order to determine
whether to execute a power-on, or power-off landing.
a. If Power-On landing:
1. LAND AS SOON AS POSSIBLE.
2. EMER SHUTDOWN after landing.
b. If Power-Off landing:
1. AUTOROTATE.
2. EMER SHUTDOWN. Accomplish during
descent if time permits.
9-30. ELECTRICAL FIRE – FLIGHT. Prior to shut-
ting off all electrical power, the pilot must consider the
equipment that is essential to a particular fl ight environ-
ment that will be encountered. In the event of electrical
fi re or suspected electrical fi re in fl ight:
1. BAT and GEN switches – OFF.
2. LAND AS SOON AS POSSIBLE.
3. EMER SHUTDOWN after landing.
9-30.1. DELETED.
9-31. SMOKE AND FUME ELIMINATION. Smoke
and/or toxic fumes entering the cockpit and cabin can
be exhausted as follows:
Do not jettison doors in fl ight above effective
translational lift.
1. Vents – Open.
2. DEFOG & VENT switch – ON.
9-32. ELECTRICAL SYSTEM MALFUNCTIONS.
9-33. GENERATOR FAILURE – NO OUTPUT. A
no-output malfunction of the generator will be indicated
by a zero indication on the DC AMMETER and a DC
GENERATOR caution light illumination. An attempt
may be made to put the generator back on line by
accomplishing the following:
1. GEN FIELD and GEN & BUS RESET
circuit breakers – Check In.
2. GEN switch – RESET then GEN – Do not
hold the switch in the RESET position.
If the generator is not restored, or if it goes off line again:
3. GEN switch – OFF.
4. Turn OFF all unnecessary electrical
equipment.
5. LAND AS SOON AS PRACTICABLE.
9-34. OVERHEATED BATTERY. An abnormally
high DC AMMETER indication is evidence of a high
battery charging rate or a battery thermal runaway. High
battery charging amperage is normal immediately after
engine start and should dissipate within minutes. DC
AMMETER indications of 30 AMPS or below is normal
after 15 minutes of aircraft operation with all systems
operating.
Do not open battery compartment or attempt to
disconnect or remove overheated battery. Bat-
tery fl uid will cause burns and overheated bat-
tery will cause thermal burns and may explode.
If high DC amperage does not dissipate:
1. BAT Switch – OFF.
If high DC amperage indication disappears with BAT
switch OFF, a high battery charging rate and possible
battery thermal runaway is con fi rmed, in this event:
9-10 Change 14
TM 55-1520-228-10