TM 1-1510-224-10 (a) Wanted.    100%    capacity  pressure at known temperature. (b) Known.  Temperature = -30C. (c) Method.    Move  left  along  100%  line to -30C line and move down to 1420 PSIG. 2-62.  WINDSHIELD WIPERS. a. Description. Two electrically-operated windshield    wipers    are    provided    for    use    at    all    flight speeds.          A     rotary     switch     (fig.          2-15)     placarded WINDSHIELD WIPER,  located  on  the  overhead  control panel,  selects  mode  of  windshield  wiper  operation.    An information  placard  above  the  switch  states:    DO  NOT OPERATE  ON  DRY  GLASS.    Function  positions  of  the switch, as read clockwise, are placarded:  PARK - OFF - SLOW - FAST.    When  the  switch  is  held  in  the  spring- loaded   PARK   setting,   the   blades   will   return   to   their normal   inoperative   position   on   the   glass,   then,   when released,   the   switch   will   return   to   the   OFF   position, terminating windshield wiper operation.  The   FAST  and SLOW  switch   positions   are   separate   operating   speed settings for wiper operation.  The windshield wiper circuit is protected by one 10-ampere circuit breaker, placarded WSHLD WIPER, located on the overhead circuit breaker panel (fig.  2-9). CAUTION Do  not  operate  windshield  wipers  on dry  glass.    Such  action  can  damage the   linkage   as   well   as   scratch   the windshield glass. b. Normal Operation.    To  start,  turn   WINDSHIELD WIPER switch to   FAST or   SLOW    speed,  as  desired. To   stop,   turn   the   switch   to   the   PARK   position   and release.        The    blades    will    return    to    their    normal inoperative position and stop.  Turning the switch only to the OFF position will stop the windshield wipers, without returning them to the normal inactive position. 2-63.  FERRY CHAIR. For ferry purposes, a forward facing chair is provided that   may   be   attached   to   the   floor   tracks   at   fuselage station 211.87. 2-64.  CIGARETTE LIGHTERS AND ASH TRAYS. The    pilot    and    copilot    have    individual    cigarette lighters and ash trays mounted in escutcheons outboard of  their  seats.    The  cigarette  lighters  are  protected  by  a 5-ampere  circuit  breaker,  placarded   CIGAR  LIGHTER, on the overhead circuit breaker panel (fig.  2-9). 2-65.  CHEMICAL TOILET. a. Description.    A  side-facing  chemical  toilet  which can also be used as an additional seat is installed in the aft   cabin   area.      Two   hinged-lid   half-sections   must   be raised to gain access to the toilet.  Waste is stored within a   removable   container   located   below   the   seat   in   the cabinet  assembly.    This  non-flushing  system  uses  a  dry chemical  preparation  to  deodorize  the  stored  waste.    A toilet    tissue    dispenser    is    contained    in    a    slide-out compartment on the forward side of the toilet cabinet.  A box  of  disposable  waste  container  liners  and  a  box  of chemical    deodorant    packets    are    also    stored    in    the cabinet. b. Operation.  During use, a removable throwaway plastic  liner  is  attached  to  the  waste  container.    After use,  dry  chemical  deodorant  obtained  from  the  storage cabinet   is   deposited   on   the   waste   and   the   hinged   lid sections are closed over the cavity.  After each flight, the waste container must be removed, emptied, relined, and replaced in the cabinet.  Consumable toilet items should be resupplied as needed. 2-66.  SUN VISORS. CAUTION When adjusting the sun visors, grasp only  by  the  top  metal  attachment  to avoid damage to the plastic shield. Individual  sun  visors  are  provided  for  the  pilot  and copilot  (fig.    2-10).    Each  visor  is  manually  adjustable. When  not  needed  as  a  sun  shield,  each  visor  may  be rotated  to  a  position  flush  with  the  top  of  the  cockpit  so that it does not obstruct view through the windows. 2-67.  RELIEF TUBE. The   relief   tube   is   located   immediately   aft   of   the cargo door on the left side of the fuselage. 2-66