TM 55-1510-220-10 4. To  release  the  parking  brakes  push  in  on  the parking brake handle. b. The   control   lock   (fig.   2-19)   holds   the   engine   and propeller  control  levers  in  a  secure  position,  and  the  elevator, rudder, and aileron in neutral position.  Install the control locks as follows: 1. With   engine   and   propeller   control   levers   in secure position, slide lock onto control pedestal to prevent operation of levers. 2. Install   elevator   and   aileron   lockpin   vertically through  pilot's  control  column  to  lock  control wheel. 3. Install   rudder   lock   pin   through   flapper   door forward of pilot's seat, making sure rudder is in neutral position. 4. Reverse    steps1    through    3    above    to    remove control lock.  Store control lock. 2-104.  INSTALLATION OF PROTECTIVE COVERS. The crew will insure that the aircraft protective covers are installed. 2-105.  MOORING. The    aircraft    is    moored    to    insure    its    immovability, protection, and security under various weather conditions.  The following paragraphs give, in detail, the instructions for proper mooring of the aircraft. a. Mooring  Provisions.    Mooring  points  (fig.  2-34)  are provided   beneath   the   wings   and   tail.      Additional   mooring cables may be attached to each landing gear.  General mooring equipment  and  procedures  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    diameter 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 circumstances.  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.        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 2-34.  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     satisfactory. 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 utilizing mooring   points   shown   in   figure   234.      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- 34.    When  anchor  kits  are  not  available,  use metal stakes or deadman type anchors, providing     they     can     successfully     sustain     a minimum pull of 3000 pounds. 2-92