TM 55-1510-220-10
WARNING
Failure of the fuel tank venting system will
prevent the fuel in the wing tanks from
gravity feeding into the nacelle tank. Fuel
vent system failure may be indicated by
illumination of the #1 or #2 NAC LOW
caution light with greater than 20 minutes of
usable fuel indicated in the main tan fuel
system. The total usable fuel remaining in
the main fuel supply system with the LOW
FUEL caution light illuminated may be as
little as 114 pounds, regardless of the total
fuel quantity indicated. Continued flight
may result in engine flameout due to fuel
starvation.
e.
Illumination of the #1 NACLOWor#2 NAC LOW
caution annunciator light. Illumination of the #1 NAC
LOW or #2 NAC LOW caution annunciator light indicates
that the affected tank has 20 minutes remaining at sea
level, normal cruise power consumption rate. Proceed as
follows:
1.
Twenty minutes fuel remaining Confirm.
2.
Land as soon as possible.
9-22. ELECTRICAL SYSTEM EMERGENCIES.
a.
DC
Generator
Caution
Annunciator
Light
Illuminated. Illumination of a #1 DC GEN or #2 DC GEN
caution annunciator light indicates failure of a generator
or one of its associated circuits (generator control unit). If
one
generator
system
becomes
inoperative,
all
nonessential
electrical
equipment
should
be
used
judiciously to avoid overloading the remaining generator.
The use of accessories which create a very high drain
should be avoided. If both generators are shut off due to
either generator system failure or engine failure, all
nonessential equipment should be turned off to preserve
battery power for extending the landing gear and wing
flaps. When a DC GEN light illuminates, perform the
following:
(1.)
Generator switch - OFF, RESET, then ON.
(2.)
Generator switch (no reset) - OFF.
(3.)
Mission control switch - OVERRIDE.
(4.)
Operating loadmeter - 100%h maximum.
b.
Both DC Generator Warning Annunciator Lights
Illuminated.
(1.)
AII nonessential equipment - OFF.
2.
Land as soon as practicable.
c.
Excessive Loadmeter Indication (Over 100%). If
either loadmeter indicates over 100%, perform the
following:
(1.)
Battery switch - OFF (monitor loadmeter).
(2.)
Loadmeter over 100% - Nonessential
electrical equipment OFF.
(3.)
Loadmeter under 100%, - BATT switch ON.
d.
Inverter Caution Annunciator Light Illuminated.
Illumination of the #1 INVERTER or #2 INVERTER
caution annunciator light indicates failure of the affected
inverter. When either inverter fails, the total aircraft load
is automatically switched. to the remaining inverter.
When a #1 INVERTER or #2 INVERTER caution
annunciator light illuminates, perform the following:
(1.)
Affected #1 INVERTER or #2 INVERTER
switch OFF.
e.
INST AC Warning Annunciator Light Illuminated.
Illumination of the INST AC warning light indicates that 26
VAC power is not available. All items connected to the 26
VAC bus will be inoperative (refer to AC wiring schematic
diagram in chapter 2 for equipment effected). Under
these conditions, power must be controlled by indications
of the N1 and TGT gages. Perform the following:
1.
N
1
and TGT indications - Check.
2.
Other engine instruments - Monitor.
f.
Circuit Breaker Tripped. If the circuit breaker is
for a nonessential item, do not reset in flight. If the circuit
breaker is for an essential item, the circuit breaker may be
reset once. If a bus feeder circuit breaker (on the
overhead circuit breaker panel) trips, a short is indicated.
Do not reset in flight. If a circuit breaker trips, perform as
follows:
(1.)
BUS FEEDER breaker tripped - Do not reset.
(2.)
Nonessential circuit - Do not reset.
(3.)
Essential circuit - Reset once.
Change 3 9-12
