TM  55-1510-221-10 NOTE To  compensate  for  loss  of  aircraft  cylin- der pressure as the oxygen cools to ambi- ent temperature after recharging, the cyl- inder  should  be  charged  initially  to approximately 10% over prescribed pres- sure. Experience will determine what ini- tial  pressure  should  be  used  to  compen- sate  for  the  subsequent  pressure  loss  upon cooling.  A  small  top-off  will  create  little heat.  A  complete  recharge  will  create  sub- stantial  heating. The final stabilized cylinder pressure should be adjusted  for  ambient  temperature  per  figure  2-31. 7.   Disconnect   oxygen   hose   from   oxygen servicing unit and tiller valve. 8.  Install  protective  cap  on  oxygen  filler valve. 9.  Install  oxygen  access  door. 2-103.  GROUND  HANDLING. Ground handling covers all the essential infor- mation  concerning  movement  and  handling  of  the aircraft  while  on  the  ground.  The  following  para- graphs give, in detail, the instructions and precau- tions  necessary  to  accomplish  ground  handling  func- tions. Parking, covers, ground handling and towing equipment are shown in figure 2-32. a. General Ground Handling Procedure. Acci- dents  resulting  in  injury  to  personnel  and  damage  to equipment  can  be  avoided  or  minimized  by  close observance  of  existing  safety  standard  and  recog- nized 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. b. Ground Handling Safety Practice. Aircraft equipped with turboprop engines require additional maintenance  safety  practices.  The  following  list  of safety practices should be observed at all times to prevent  possible  injury  to  personnel  and/or  damaged or  destroyed  aircraft: (1.)  Keep   intake   air   ducts   free   of   loose articles such as rags, tools, etc. (2.) Stay  clear  of  exhaust  outlet  areas. (3.) During ground runup, make sure the brakes  are  firmly  set. 2-86 (4.) Keep  area  fore  and  aft  of  propellers clear of maintenance equipment. (5.)  Do  not  operate  engines  with  control surfaces in the locked position. (6.) Do  not  attempt  towing  or  taxiing  of the aircraft with control surfaces in the locked posi- tion. (7.) When high winds are present, do not unlock the control surfaces until prepared to prop- erly  operate  them. (8.)  Do  not  operate  engines  while  towing equipment is attached to the aircraft, or while the aircraft is tied down. (9.) Check  the  nose  wheel  position.  Unless it  is  in  the  centered  position,  avoid  operating  the engines  at  high  power  settings. (10.)  Hold  control  surfaces  in  the  neutral position when the engines are being operated at high power  settings. (11.)  When   moving   the   aircraft,   do   not push  on  propeller  deicing  boots.  Damage  to  the heating  elements  may  result. c. Moving Aircraft on Ground. Aircraft on the ground  shall  be  moved  in  accordance  with  the  fol- lowing: (1.)  Taxiing.  Taxiing  shall  be  in  accor- dance with chapter 8. When the aircraft is being towed, a quali- fied person must be in the pilot’s seat to maintain  control  by  use  of  the  brakes. When  towing,  do  not  exceed  nose  gear turn limits. Avoid short radius turns, and always  keep  the  inside  or  pivot  wheel turning during the operation. Do not tow aircraft  with  rudder  locks  installed,  as severe damage to the nose steering linkage can  result.  When  moving  the  aircraft backwards,  do  not  apply  the  brakes abruptly.  Tow  the  aircraft  slowly,  avoid- ing sudden stops, especially over snowy, icy,  rough,  soggy,  or  muddy  terrain.  In arctic  climates,  the  aircraft  must  be  towed by the main gears, as an immense break- away  load,  resulting  from  ice,  frozen  tires, and  stiffened  grease  in  the  wheel  bearings may damage the nose gear.