TM  55-1510-221-10 conditions. The following paragraphs give, in detail, the instructions for proper mooring of the aircraft. a.   Mooring   Provisions.   Mooring  points  (fig. 2-33)  are  provided  beneath  the  wings  and  tail.  Addi- tional mooring cables may be attached to each land- ing gear.   General  mooring  equipment  and  proce- dures necessary to moor the aircraft, in addition to the  following,  are  given  in  TM  55-1500-204-25/1. (1.) Use mooring cables of 1/4 inch diam- eter aircraft cable and clamp (clip-wire rope), chain or  rope  3/8  inch  diameter  or  larger.  Length  of  the cable  or  rope  will  be  dependent  upon  existing  cir- cumstances. Allow sufficient slack in ropes, chains, or cable to compensate for tightening action due to moisture absorption of rope or thermal contraction of cable or chain. Do not use slip knots. Use bowline knots to secure aircraft to mooring stakes. (2.)  Chock  the  wheels. b. Mooring Procedures for High Winds. Struc- tural  damage  can  occur  from  high  velocity  winds; therefore,  if  at  all  possible,  the  aircraft  should  be moved to a safe weather area when winds above 75 knots  are  expected.  Moored  aircraft  condition  is shown in figure 2-33. If aircraft must be secured use the  following  steps: 1. After aircraft is properly located, place nose wheel in centered position. Head aircraft into the wind, or as nearly so as is possible within limits determined by  locations  of  fixed  mooring  rings. When necessary, a 45 degree variation of  direction  is  considered  to  be  satis- factory. Locate each aircraft at slightly more than wing span distance from all other  aircraft.  Position  nose  mooring point approximately 3 to 5 feet down- wind from ground mooring anchors. 2.  Deflate  nose  wheel  shock  strut  to within  3/4  inch  of  its  fully  deflated position. 3. Fill  all  fuel  tanks  to  capacity,  if  time permits. 4.  Place  wheel  chocks  fore  and  aft  of main gear wheels and nose wheel. Tie each pair of chocks together with rope or  join  together  with  wooden  cleats nailed  to  chocks  on  either  side  of wheels.  Tie  ice  grip  chocks  together with  rope.  Use  sandbags  in  lieu  of chocks when aircraft is moored on steel mats. Set parking brake as applicable. 5.  Accomplish  aircraft  tiedown  by  utiliz- ing   mooring   points   shown   in   figure 2-33. Make tiedown with 1/4 inch air- craft cable, using two wire rope clips or bolts,  and  a  chain  tested  for  a  3000 pound  pull.  Attach  tiedowns  so  as  to remove  all  slack.  (Use  a  3/4-inch  or larger manila rope if cable or chain tie- down is not available.) If rope is used for  tiedown,  use  anti-slip  knots,  such  as bowline knot, rather than slip knots. in the event tiedown rings are not avail- able on hard surfaced areas, move air- craft  to  an  area  where  portable  tie- downs can be used. Locate anchor rods at  point  shown  in  figure  2-33.  When anchor kits are not available, use metal stakes  or  deadman  type  anchors,  pro- viding  they  can  successfully  sustain  a minimum pull of 3000 pounds. 6. In event nose position tiedown is con- sidered  to  be  of  doubtful  security  due to  existing  soil  condition,  drive  addi- tional  anchor  rods  at  nose  tiedown position.  Place  padded  work  stand  or other  suitable  support  under  the  aft fuselage  tiedown  position  and  secure. 7.  Place  control  surfaces  in  locked  posi- tion  and  trim  tab  controls  in  neutral position.  Place  wing  flaps  in  up  posi- tion. 8.  The  requirements  for  dust  excluders, protective  covers,  and  taping  of  open- ings will be left to the discretion of the responsible maintenance officer or the pilot  of  the  transient  aircraft  (fig.  2-32). 9.  Secure  propellers  to  prevent  windmill- ing (fig. 2-32). 10.   Disconnect   battery. 11. During typhoon or hurricane wind con- ditions,  mooring  security  can  be  fur- ther  increased  by  placing  sandbags along the wings to break up the aerody- namic  flow  of  air  over  the  wing, thereby reducing the lift being applied against the mooring by the wind. The storm appears to pass two times, each time  with  a  different  wind  direction. This  will  necessitate  turning  the  air- craft  after  the  first  passing.  sli.After high winds, inspect aircraft for visible signs of structural damage and for evi- dence  of  damage  from  flying  objects. Service nose shock strut and reconnect battery. 2-89