TM 1-1510-224-10 Section V.  FLIGHT CONTROLS 2-34.  FLIGHT CONTROL SYSTEM. The    aircraft's    primary    flight    control    system consists   of   conventional   rudder,   elevator,   and   aileron control surfaces.  These surfaces are manually operated from   the   cockpit   through   mechanical   linkage   using   a control    wheel    for    the    ailerons    and    elevators,    and adjustable  rudder/brake  pedals  for  the  rudder.    Both  the pilot and copilot have flight controls.  Trim control for the rudder,  elevators,  and  ailerons  is  accomplished  through a  manually  actuated  cable-drum  system  for  each  set  of control    surfaces.        The    autopilot    has    provisions    for controlling     the     position     of     the     ailerons,     elevators, elevator trim tab, and rudder. 2-35.  CONTROL WHEELS. Elevator and aileron control surfaces are operated   by   manually   actuating   either   the   pilot's   or copilot's  control  wheel  (fig.  2-24).    A  control  wheel  is installed on each side of the instrument panel.  Switches are   installed   in   the   outboard   grip   of   each   wheel   to operate  the  elevator  trim  tabs.    A  microphone  switch, CHAFF DISPENSE     switch,     and     an     autopilot/yaw damp/electric trim disconnect switch are also installed in the   outboard   grip   of   each   control   wheel.      A   FLARE DISPENSE  switch  is  installed  on  top  of  the  inboard  grip of  each  control  wheel.    A  transponder  ident  switch  is installed  on  the  forward  side  of  the  inboard  grip  of  each control  wheel.    Installed  in  the  center  of  each  control wheel is a digital electric clock.  A map light switch, and TCS (touch control steering) switch are located adjacent to each digital clock. 2-36.  RUDDER SYSTEM. a.    Rudder  Pedals.    Aircraft  rudder  control  and nose wheel steering is accomplished by actuation of the rudder  pedals  from  either  the  pilot's  or  copilot's  station (fig.   2-10).      The   rudder   pedals   may   be   individually adjusted,  forward  or  aft;,'  to  provide  adequate  leg  room for the pilot and copilot.  Adjustment is accomplished by depressing the lever alongside the rudder pedal arm and moving  the  pedal,  forward  or  aft,  until  the  locking  pin engages in the selected position. b.  Yaw Damper System.  A yaw damper system is   provided   to   aid   the   pilot   in   maintaining   directional stability  and  increase  ride  comfort.    The  system  may  be used   at   any   altitude,   but   is   required   for   flight   above 17,000   feet.      It   must   be   deactivated   for   takeoff   and landing.      The   yaw   damper   system   is   a   part   of   the autopilot.    The  system  is  controlled  by  a    YAW  DAMP switch located on the autopilot control panel.  Operating instructions for this system are contained in Chapter 3. c.    Rudder  Boost  System.    The   rudder   boost system is a torque sensing, linear actuating system.  The system utilizes a pressure transducer on each engine to sense engine torque oil pressure, a stability augmentation  computer  to  monitor  torque  levels,  and  a rudder servo to apply boost to aid the pilot. The   stability   augmentation   computer   monitors torque   levels   and   airspeed   to   determine   if   boost   is required.      The   level   of   boost   is   proportional   to   the difference  in  torque  between  each  engine  and  inversely proportional to airspeed. Boost commences at approximately  50%  torque  differential  and  increases  to maximum at 100% torque differential.  The level of boost available  is  inversely  proportional  to  airspeed  such  that maximum  rudder  boost  is  obtained  at  100%  differential and  low  airspeed  (80  knots),  while  no  rudder  boost  is available at high airspeeds (above 180 knots). The   rudder   boost   system   is   controlled   by   a switch,   placarded    RUDDER   BOOST   -   OFF   -   YAW CONTROL TEST, located on the pedestal extension (fig. 2-14).  The rudder boost system is powered through a 5-ampere circuit breaker, placarded RUDDER BOOST,  located  on  the  overhead  circuit  breaker  panel (fig. 2-9). 2-37.  FLIGHT CONTROL LOCKS. CAUTION Remove    control    locks    before    towing    the aircraft or starting engines.  Serious damage could  result  in  the  steering  linkage  if  towed by a tug with the rudder lock installed. Positive    locking    of    the    rudder,    elevator    and aileron  control  surfaces,  and  engine  controls  (POWER levers,    PROP    levers,    and     CONDITION     levers)     is provided    by    a    removable    lock    assembly    (fig.    2-25) consisting of two pins, and an elongated U-shaped strap interconnected   by   a   chain.      Installation   of   the   control locks  is  accomplished  by  inserting  the  U-shaped  strap around the aligned control levers from the copilot's side; then the aileron/elevator locking pin is inserted through a guide   hole   in   the   top   of   the   pilot's   control   column assembly.  The rudder is held in a neutral position by an L-shaped  pin  which  is  installed  through  a  guide  hole  in the   floor   aft   of   the   pilot's   rudder   pedals.      The   rudder pedals  must  be  centered  to  align  the  hole  in  the  rudder bellcrank  with  the  guide  hole  in  the  floor.    Remove  the locks  in  reverse  order  (rudder  pin,  control  column  pin, and power control clamp). 2-38.  TRIM TABS. Trim    tabs    are    provided    for    all    flight    control surfaces.        These    tabs    are    manually    actuated,    and mechanically controlled by a cable-drum and jack-screw actuator system 2-50