TM 1-1510-218-10 2-55 CAUTION In turbulence or during maneuvers, the NO FUEL XFR light may momentarily illuminate after    the    auxiliary    fuel    has    completed transfer. d.  Fuel   Transfer   Pumps.       The  auxiliary  tank fuel  transfer  system  automatically  transfers  the  fuel from the auxiliary tank to the nacelle tank without pilot action.      Motive   flow   to   a   jet   pump   mounted   in   the auxiliary  tank  sump  is  obtained  from  the  engine  fuel plumbing  system  downstream  from  the  engine  driven boost  pump  and  routed  through  the  transfer  control motive  flow  valve.   The motive flow valve is energized to the open position by the control system to transfer auxiliary  fuel  to  the  nacelle  tank  to  be  consumed  by the engine during the initial portion of the flight.  When an  engine  is  started,  pressure  at  the  engine  driven boost pump closes a pressure switch which, after a 30 to   50-second   time   delay   to   avoid   depletion   of   fuel pressure   during   starting,   energizes   the   motive   flow valve.  When auxiliary fuel is depleted, a low level float switch de-energizes the motive flow valve after a 30 to 60-second  time  delay  provided  to  prevent  cycling  of the motive flow valve due to sloshing fuel.  In the event of  a  failure  of  the  motive  flow  valve  or  the  associated control circuitry, the loss of motive flow pressure when there is still fuel remaining in the auxiliary fuel tank is sensed   by   a   pressure   switch   and   a   float   switch, respectively, which illuminates a light, placarded  #1 or #2  NO  FUEL  XFR, on the annunciator panel.   During engine  start,  the  pilot  should  note  that  the   NO FUEL XFR  lights  extinguish  30  to  50  seconds  after  engine start.    The  NO  FUEL  XFR  lights  will  not  illuminate  if auxiliary   tanks   are   empty.      A   manual   override   is incorporated  as  a  backup  for  the  automatic  transfer system.        This    is    initiated    by    placing    the    AUX TRANSFER  switch,  located  in  the  fuel  management panel, to the OVERRIDE  C  D  T1  position or the AUX XFER  switch  to  the    OVRD  position   T2  .     Refer to Figure  2-19.    This  will  energize  the  transfer  control motive flow valve.   The transfer system is protected by 5-ampere    circuit    breakers,    placarded    AUXILIARY TRANSFER #1 or   #2, located on the overhead circuit breaker panel, Figure 2-16. e.   Fuel    Gauging    System.        The    total    fuel quantity in the left or right main system or left or right auxiliary  tank  is  measured  by  a  capacitance type fuel gauging system.  Two fuel gauges, one for the left and one   for   the   right   fuel   system,   read   fuel   quantity   in pounds.    Refer  to  Section  XII  for  fuel  capacities  and weights.   The system is compensated for fuel density changes due to temperature excursions.  In addition to the fuel gauges, yellow  #1 or  #2  NAC  LOW lights on the caution/advisory annunciator panel illuminate when there  is  approximately  153  pounds   C  or  247  pounds   D,  T  of  usable  fuel  per  engine  remaining.    The  fuel gauging  system  is  protected  by  individual  5-ampere circuit breakers, placarded  QTY IND and  QTY WARN #1   or   #2,   located   on   the   overhead   circuit   breaker panel. f.    Fuel Management Panel. The fuel management panel is located on the cockpit overhead between   the   pilot   and   copilot.      It   contains   the   fuel gauges, standby fuel pump switches, crossfeed valve switch, fuel gauging system control switch and transfer control switches.  Refer to Figure 2-19. (1)   Fuel  Gauging  System  Control  Switch.    A switch    on    the    fuel    management    panel,    placarded FUEL  QUANTITY  MAIN  /  AUXILIARY,  controls  the fuel gauging system.   When in the  MAIN position, the fuel gauges read the total fuel quantity in the left and right   wing   fuel   system.      When   in   the   AUXILIARY position,  the  fuel  gauges  read  the  fuel  quantity in the left and right auxiliary tanks only. (2)   Standby    Fuel    Pump    Switches.        Two switches, placarded  STANDBY PUMP ON located on the fuel management panel, control a submerged fuel pump    located    in    the    corresponding    nacelle    tank.   During normal aircraft operation, both switches are off so long as the engine-driven boost pumps function and during crossfeed operation.   The loss of fuel pressure, due   to   failure   of   an   engine-driven  boost  pump,  will illuminate    the    MASTER    WARNING    light    on    the glareshield  and  will  illuminate the  #1 FUEL PRESS or #2  FUEL  PRESS  on  the  warning  annunciator  panel, Figure  2-17.    Turning  ON the  STANDBY  PUMP  will extinguish the   FUEL  PRESS  lights.     The  MASTER WARNING light must be manually cleared. (3)   Each ferry fuel tank has a 10-foot 1/4-inch flex  hose  with  a  quick  drain  installed  in  the  aft  end.   When   the   ferry   fuel   system   is   in   use,   the   preflight inspection  also  includes  draining  a  small  amount  of fuel  from  these  drains  to  drain  off  any  moisture  that may have been inadvertently introduced into the tanks.   Place  the  aft  end  of  the  hoses  out  through  the  cabin entrance  door,  hold  a  fuel-proof  container  under  the ends, and drain about a pint of fuel out of each line.