TM 55-1510-222-10 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. Structural  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 2-36.      If   aircraft   must   be   secured,   use   the   following steps: 1. After   aircraft   is   properly   located,   place nose  wheel  in  centered  position.    Point  the  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  satisfactory.    Locate  each  aircraft  at slightly more than one wing span distance from all other aircraft.  Position nose mooring point approximately 3 to 5 feet downwind 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. Tie    aircraft    down    by    utilizing    mooring points shown in figure 2-36.  Make tiedown with 1/4 inch aircraft  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 tiedown 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 available on hard surfaced areas, move aircraft to an area where portable tiedowns can be used.  Locate anchor rods at point shown in figure 2-36.  When anchor kits are not available, use metal stakes or deadman type anchors,    providing    they    can    successfully    sustain    a minimum pull of 3000 pounds. 6. In event nose position tiedown is considered to be of doubtful security due to existing soil condition,  drive  additional  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  position and  trim  tab  controls  in  neutral  position.    Place  wing flaps in up position. 8. The    requirements    for    dust    excluders, protective covers, and taping of openings will be left to the discretion of the responsible maintenance officer or the pilot of the transient aircraft (fig.  2-34). 9. Secure  propellers  to  prevent  windmilling (fig.  2-34). 10. Disconnect battery. 11. During typhoon or hurricane wind conditions,  mooring,  security  can  be  further  increased by  placing  sandbags  along  the  wings  to  break  up  the aerodynamic 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 aircraft after the first passing. 12. After    high    winds,    inspect    aircraft    for visible  signs  of  structural  damage  and  for  evidence  of damage  from  flying  objects.    Service  nose  shock  strut and reconnect battery. 2-94