TM 55-1510-220-10 limitations arc imposed when alternate or emergency fuels are used.    For  the  purpose  of  recording.    Fuel  mixtures  shall  be identified  as  to  the  major  component  of  the  mixture.    except when  the  mixture  contains  leaded  gasoline.    The  use  of  any emergency  fuels  will  be  entered  in  the  FAULTS/REMARKS column   of   DA   Form   2408-13,   Aircraft   Maintenance   and Inspection   Record,   noting   the   type   of   fuel.      additives,   and duration of operation. b. Use of Kerosene Fuels.  The use of kerosene fuels (JP- 5  type)  in  turbine  engines  dictates  the  need  for  observance  of special  precautions.    Both  ground  starts  and  air  starts  at  low ambient  temperature  may  become  difficult  due  to  low  vapor pressure. c. Mixing  of  Fuels  in  Aircraft  Tanks.    When  changing from one type of authorized fuel to another, for example JP-4 to JP-5, it is not necessary to drain the aircraft fuel system before adding the new fuel. d. Fuel  Specifications.      Fuel   having   the   same   NATO code   number   are   interchangeable.      Jet   fuels   conforming   to ASTM  D-1655  specification  may  be  used  when  MIl,T-5624 fuels   are-not   available.      This   usually   occurs   during   cross- country  flights  where  aircraft  using  NATO  F-44  (JP-5,)  are refueling with NATO F40 (JP-4) or Commercial ASTM type B fuels.    Whenever  this  condition  occurs,  the  engine  operating characteristics may change in that lower operating temperature, slower  acceleration,  lower  engine  speed,  easier  starting,  and shorter  range  may  be  experienced.    The  reverse  is  true  when changing  from  F-40  (JP-4)  fuel  to  F-44  (JP-5)  or  Commercial ASTM Type A-1 fuels.  Most commercial turbine engines will operate satisfactorily on either kerosene or JP-4 type fuel.  The difference  in  specific  gravity  may  possibly  require  fuel  control adjustments;  if  so,  the  recommendations  of  the  manufacturers of the engine and airframe are to be followed. 2-94.  SERVICING OIL SYSTEM An integral oil tank occupies the cavity formed between the accessory gearbox housing and the compressor inlet case on the engine.  The tank has a calibrated oil dipstick and an oil drain plug.    Avoid  spilling  oil.    Any  oil  spilled  must  be  removed immediately.    Use  a  cloth  moistened  in  solvent  to  remove  oil. Overfilling may cause a discharge of oil through the accessory gearbox  breather  until  a  satisfactory  level  is  reached.    Service oil system as follows: 1. Open  the  access  door  on  the  upper  cowling  to gain access to the oil filler cap and dipstick. CAUTION A    cold    oil    check    is    unreliable.        If possible,   check   oil   within   10   minutes after    engine    shutdown.        If    over    10 minutes have elapsed, motor the engine (starter   only)   for   15-20   seconds,   then recheck.  If over 10 hours have elapsed, start the engine and run for 2 minutes, then recheck.  Add oil as required.  Do not overfill. 2. Remove oil filler cap. 3. Insert a clean funnel, with a screen incorporated, into the filler neck. 4. Replenish   with   oil   to   within   1   quart   below MAX  mark  or  the  MAX  COLD  (on  dipstick (cold engine).  Fill to MAX or MAX HOT (hot engine). 5. Check   oil   filler   cap   for   damaged   performed packing, general condition and locking. CAUTION Insure   that   oil   filler   cap   is   correctly installed and securely locked to prevent loss of oil and possible engine failure. 6.     If oil  level  is  over  2  quarts  low,  motor  or  run engine as required and as is necessary. 7.     Install and secure oil filter cap. 8.     Check for any oil leaks. 2-95.        SERVICING    HYDRAULIC    BRAKE    SYSTEM RESERVOIR. 1. Gain access to brake hydraulic system reservoir.. 2. Remove   brake   reservoir   cap   and   fill   reservoir   to washer on dipstick with hydraulic fluid. 3. Install brake- reservoir cap. Change 2   2-84