TM 1-1510-223-10 9-10           Change 3 d.   Fuel Crossfeed.  For fuel crossfeed, perform the following: 1.  AUX XFER switches — AUTO. 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 PUMP switches — Off. 3.  CROSSFEED switch — As required. 4.  FUEL  CROSSFEED  annunciator  illuminated — Check. NOTE With the FIRE PULL handle pulled, the FUEL PRESS annunciator will remain illuminated on the side supplying fuel. 5.  FUEL  PRESS  annunciator  extinguished  — Check. 6.  Fuel quantity — Monitor. e.   NAC LOW Annunciator Illuminated. Illumination of the #1 or #2 NAC LOW caution annunciator indicates that the affected tank has approximately 30 minutes (58 gal- lons) of usable fuel remaining at sea level, at maximum cruise power consumption rate. Proceed as follows: WARNING Failure of the fuel tank venting systems will pre- vent the fuel in the wing tanks from gravity feed- ing 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 30 min- utes 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 little as 140 pounds, regardless  of  the  total  fuel  quantity  indicated. Continued flight may result in engine flameout due to fuel starvation. 1.   Land as soon as practicable. 9-27.   ELECTRICAL SYSTEM EMERGENCIES. a.   DC  GEN  Annunciator  Illuminated.  When  a  DC GEN annunciator illuminates, perform the following: 1.  GENERATOR  switch  —  OFF,  RESET,  then ON. 2.  GENERATOR switch (no reset) — OFF. 3.  MISSION CONTROL switch — ORIDE. 4.  Operating loadmeter — 100% maximum. b.   Both  DC  GEN  Annunciators  Illuminated  (reset failed). 1.  All nonessential equipment — Off. 2.   Land as soon as practicable. c.   Excessive  Loadmeter  Indication  (over  100%).  If either loadmeter indicates over 100%, perform the fol- lowing: 1.  BATTERY switch — OFF (monitor loadmeter). 2.  Loadmeter over 100% — Nonessential electri- cal equipment off. 3.  Loadmeter under 100% — BATTERY switch ON. d.   INVERTER Annunciator Illuminated. When either #1 or #2 INVERTER annunciator illuminates, perform the following: 1.  Affected INVERTER switch — Off. e.   INST AC Annunciator Illuminated. NOTE Illumination of the INST AC warning annunciator indicates that both 26 VAC circuits are inopera- tive. The following systems will be affected. NAV #1 NAV #2 Heading #1 Heading #2 #1 torquemeter #2 torquemeter Pilot’s EFIS Copilot’s EFIS INS ADF #2 rate of turn Air data computer Under these conditions power must be governed by indications of N1 and TGT gages. Perform the following: 1.   N1 and TGT indications — Check. 2.   Other engine instruments — Monitor. f.    Circuit Breaker Tripped. If a circuit breaker trips, perform the following: 1.   Bus feeder breaker tripped — Do not reset.