TM 55-1510-222-10 Table 2-3.  Fuel Sump Drain Locations NUMBER DRAINS LOCATION 1 Leading Edge Tank Outboard of nacelle, underside of wing 1 Integral Tank Underside of wing, forward of aileron 1 Firewall Fuel Filter Underside of cowling forward of firewall 1 Sump Strainer Bottom center of nacelle forward of wheel well 1 Gravity Feed Line Aft of wheel well 1 Auxiliary Tank At wing root, just forward of the flap BT00195 Section V.  FLIGHT CONTROLS 2-35.  DESCRIPTION. The    aircraft's    primary    flight    control    systems consist   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  con-trol  for the    rudder,    elevator    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. 2-36.  CONTROL WHEELS. Elevator and aileron control surfaces are operated by   manually   actuating   either   the   pilot's   or   copilot's control   wheel.      These   control   wheels   (fig.   2-20)   are 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.    In  addition,  a transponder   ident   switch   is   installed   on   top   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. 2-37.  RUDDER SYSTEM. a.    Rudder  Pedals.    Aircraft  rudder  control  and nose wheel steering is accomplished by actuation of the rudder pedals from either pilot's or copilot's station (fig. 2-7).  The rudder pedals may be individually adjusted, in either a forward or aft position, 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   damp   system   is   a   part   of   the autopilot.      Operating   instructions   for   this   system   are contained  in  Chapter  3.    The  system  is  controlled  by  a YAW DAMP switch located in the autopilot control head. An   annunciator   placarded   ELEC   TRIM   OFF   in   the caution/advisory  annunciator  panel  indicates  failure  or disconnect of the electric trim system. c.    Rudder  Boost  System.    The  RC-  12K  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 the 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  about 60%   torque   differential   and   increases   to   maximum torque at 100% 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). 2-39