NOTE
With the FIRE PULL handle pulled. the
fuel in the auxiliary tank for that side will
not be available (usable) for crossfeed.
2.
Standby pumps - OFF.
3.
Crossfeed switch - As required.
4. Fuel crossfeed advisory annunciator
light - Check illuminated.
NOTE
With the FIRE PULL handle pulled, the
respective WI FUEL PRESS or #2 FUEL
PRESS light will remain illuminated on
the side supplying fuel.
5. Fuel pressure light extinguished -
Check.
6. Fuel quantity - Monitor.
e. Illumination of the #1 NAC LOW or #2
NAC LOW caution annunciator fight. 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:
Failure of the fuel tank venting system will
prevent the fuel in the wing tanks from gravity
feeding into the nacell 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 tank fuel system. The total usable fuel
remaining in the main fuel supply system with
the LOW FUEL caution light illuminated may
be as Iittle as 114 pounds, regardless of the
totaI fuel quantity indicated. Continued fIight
may result in engine flameout due to fuel star-
vation.
1.
Twenty minutes fuel remaining - Con-
firm:
2.
Land as soon as possible.
NOTE
If a "NAC LOW" light occurs about the
time the "AUX" tanks go empty and the
fuel gages show the main tanks "FULL".
TM 55-1510-221-10
this may indicate the fuel vent float valve
in the wet section has stuck. Rocking the
aircraft or changing pitch will probably
unstick it. If not. fuel may be crossfed.
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 (gener-
ator 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 sys-
tem failure or engine failure. all nonessential equip
ment 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% maxi-
mum.
b. Both DC Generator Warning Annunciator
Lights Illuminated.
1.
All nonessential equipment - OFF.
2.
Land as soon as practicable.
c. Excessive Loadmeter Indication (Over
100%). If either loadmeter indicates over 100%, per-
form the following:
1.
Battery switch - OFF (monitor load-
meter).
2. Loadmeter over 100% - Nonessential
electrical equipment OFF.
3.
Loadmeter under 100% - BATT switch
ON.
d.
Inventer Caution Annunciator Light Illumi-
nated. Illumination of the #1 INVERTER or #2
lNVERTER caution annunciator light indicates fail-
ure 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 illumi-
nates, perform the following:
1.
Affected #1 INVERTER or #2
INVERTER switch - OFF.
Change 1
9-11
