TM 1-1510-225-10 2-130 2-98.  SERVICING OXYGEN SYSTEM. The oxygen system furnishes emergency breathing oxygen to the pilot, copilot, passengers, and first aid position.  Oxygen cylinder location is shown in Figure 2-24. a.   Oxygen System Safety Precautions.  Keep    fire    and    heat    away    from    oxygen equipment.    Do  not  smoke  while  working with  or  near  oxygen  equipment,  and  take care not to generate sparks with carelessly handled tools when working on the oxygen system. 1.   Keep oxygen regulators, cylinders, gauges,   valves,   fittings,   masks,   and   all other  components  of  the  oxygen  system free of oil, grease, gasoline, and all other readily    combustible    substances.        The utmost care shall be exercised in servicing,   handling,   and   inspecting   the oxygen system. 2.   Do    not    allow    foreign    matter    to    enter oxygen lines. 3.   Never allow electrical equipment to come into contact with the oxygen cylinder. 4.   Never  use  oxygen  from  a  cylinder  without first    reducing    its    pressure    through    a regulator. b.  Replenishing Oxygen System. 1.   Remove oxygen access door on outside of aircraft. 2.   Remove protective cap on oxygen system filler valve. 3.   Attach oxygen hose from oxygen servicing unit to filler valve. If   the   oxygen   system  pressure  is  below 200 psi,  do  not  attempt  to  service  system.   Make an entry on DA Form 2408-13-1. 4.   Ensure that supply cylinder shutoff  valves on aircraft are open. 5.   Slowly     adjust     valve     position     so     that pressure increases at a rate not to exceed 200 psig per minute. 6.   Close pressure regulating valve on oxygen servicing   unit   when   pressure   gauge   on oxygen system indicates pressure obtained using the Oxygen System Servicing Pressure Chart, Figure 2-44. NOTE To compensate for loss of aircraft cylinder pressure  as  the  oxygen  cools  to  ambient temperature  after  recharging,  the  cylinder should be charged initially to approximately 10% over prescribed pressure.  Experience will determine what initial pressure should be used to compensate  for  the  subsequent  pressure loss  upon  cooling.    A  complete  recharge will create substantial heating. 7.   Adjust the final stabilized cylinder pressure for ambient temperature per Figure 2-44. 8.   Disconnect    oxygen    hose    from    oxygen servicing unit and filler valve. 9.   Install    protective    cap    on    oxygen    filler valve. 10.    Install oxygen access door. 2-99.  GROUND HANDLING. Ground handling covers all the essential information concerning movement and handling of the aircraft while on the ground.  The following paragraphs give,    in    detail,    the    instructions    and    precautions necessary  to  accomplish  ground  handling  functions.   Parking, covers, ground handling, and towing equipment are shown in Figure 2-45. a.   General Ground Handling Procedure.   Accidents resulting in injury to personnel and damage to  equipment  can  be  avoided  or  minimized  by  close observance of existing safety standards and recognized ground handling procedures.   Carelessness  or  insufficient  knowledge  of  the  aircraft or    equipment    being    handled    can    be    fatal.        The applicable  technical  manuals  and  pertinent  directives should be studied for familiarization with the aircraft, its components,    and    the    ground    handling    procedures applicable    to    it,    before    attempting    to    accomplish ground handling. WARNING WARNING