TM  55-1510-221-10 5-9.  AUTOPILOT  LIMITATIONS. WARNING The RC-12H aircraft is certified with wingtip pods  installed.  Should  the  pods  be  removed, the autopilot system must be replaced with a standard C-12D autopilot. Affected wiring must also be changed. b. Fuel Management. Auxiliary tanks will not be filled for flight unless the main tanks are full. Maximum allowable fuel imbalance is 400 lbs. Do not take off if fuel quantity gages indicate in yellow arc (less than 265 lbs. of fuel in each main tank). Crossfeed only during single  engine  operation. a. An autopilot preflight check must be. conducted and found satisfactory prior to each flight on which the autopilot is to be used. b. A pilot must be seated at the controls with the seat belt fastened when the autopilot is in operation. c.   Fuel   System   Anti-Icing.   Icing   inhibitor conforming   to   MIL-I-27686   will   be   added   to commercial  fuel,  not  containing  an  icing  inhibitor, during   fueling   operations,   regardless   of   ambient temperatures. The   additive   provides   anti-icing protection  and  also  functions  as  a  biocide  to  kill microbial growth in aircraft fuel systems. 5-11. BRAKE DEICE LIMITATIONS. c. Operation of the autopilot and yaw damper is prohibited during takeoff and landing, and below 200 The following limitations apply to the brake deice feet  above  terrain.  Maximum  speed  for  autopilot system: operation is 243 KIAS/O.47 Mach. a. The brake deice system shall not be operated at d. During a coupled ILS approach do not operate ambient  temperatures  above  15°C. the propellers in the 1750 to 1850 RPM range. b. The brake deice system shall not be operated longer  than  10  minutes  (one  timer  cycle)  with  the landing  gear  retracted.  If  operation  does  not automatically  terminate  approximately  10  minutes  after gear retraction, turn the brake deice switch OFF. 5-10.  FUEL  SYSTEM  LIMITS. NOTE Aviation  gasoline  (AVGAS)  contains  a  form  of lead which has an accumulative adverse effect on  gas  turbine  engines.  The  lowest  octane AVGAS  available  (less  lead  content)  should  be used. If any AVGAS is used the total operating time must be entered on DA Form 2408-13. a.  Operating  Limits.  Operation   with   FUEL PRESS light on is limited to IO hours. Log FUEL PRESS  light  on  time  on  DA  Form  2408-13.  One standby boost pump may be inoperative for takeoff. (Crossfeed fuel will not be available from the side with the inoperative standby boost pump.) Operation on aviation gasoline is time limited to 150 hours between engine  overhaul  and  altitude  limited  to  20,000  feet  with one   standby   boost   pump   inoperative.   Crossfeed capability is required for climb, when using aviation c.  Maintain 85% N₁   or  higher  during simultaneous operation of the brake deice and surface deice systems. If adequate pneumatic pressure cannot be provided for simultaneous operation of the brake deice and surface deice systems, turn OFF the brake deice  system. d. In  order  to  maintain  an  adequate  supply  of systems pneumatic bleed air, the brake deice system shall be turned OFF during single engine operation. 5-12.   PITOT  HEAT  LIMITATIONS. Pitot heat should not be used for more than 15 minutes while the aircraft is on the ground. gasoline  above  20,000  feet. Change  4  5-5