TM 1-1510-218-10 3C-36 3C-16.  STANDBY ATTITUDE REF ERENCE SYSTEM a.   Description.    The  standby  attitude  indicator, located  below  the  TCAS  II  display,  Figure  3C-15,  is powered  by  engine  bleed  air  and  provides  a  visual reference  of  the  aircraft  pitch  and  roll.    The  attitude indicator is comprised of a self-contained gyro to erect the  sphere  providing  the  pitch  and  roll  reference,  an indicating    symbol    representing    the    aircraft,    and    a horizontal    line    behind    the    indicating    symbol    that represents    the    horizon.        The    moveable    indicating symbol    may    be    adjusted    vertically    to    correct    for variations   in   level   flight   attitudes   by   a   small   knob located on the front base of the indicator. 1.  Attitude Sphere 2.  Roll Index 3.  Roll Pointer 4.  Horizon Line 5.  Pitch Knob 6.  Pitch  Scale 7.  Symbolic Miniature Aircraft Figure 3C-15.  Standby Attitude Indicator b.  Controls and Indexes. (1)   Attitude    Sphere.        Contains    gyro    and reference lines for pitch and roll degrees. (2)   Roll    Index.        Rotates    with    aircraft    to provide  measurement  of  angular  displacement  by  the roll pointer. (3)   Roll Pointer.    Indicates  vertical  in  any  roll attitude. (4)   Horizon   Line.      Indicates   earth   horizon relative to aircraft pitch attitude. (5)   Pitch    Knob.        Rotates    to    adjust    the miniature aircraft. (6)   Pitch Scale. Measures pitch displacement of miniature aircraft. (7)   Symbolic  Miniature  Aircraft.    Represents aircraft   nose   and   wings.      Indicates   pitch   and   roll attitude   relative   to   the   horizon.      Adjustable   through pitch knob for varying pitch attitudes. 3C-17.  TURN AND SLIP INDICATORS. a.   Description.    One  turn  and  slip  indicator  is installed  on  the  pilot’s  side  of  the  instrument  panel.   This indicator is gyroscopically controlled.  The pilot’s unit  is  operated  by  dc  power.    It  is  protected  by  a 5-ampere  circuit  breaker,  placarded   PILOT  TURN  & SLIP,  on  the  overhead  circuit  breaker  panel,  Figure 2-16. b.  Control, Indicator, and Functions. (1)   Turn   Rate  Indicator.    Indicates  direction and  rate  of  turn.    A  2-minute  turn  rate  is  indicated when  the  turn  rate  indicator  is  deflected  one  needle width to the left of the index. (2)   Index.  A reference mark for alignment of the turn rate indicator. (3)   GYRO   Warning   Flag   (Pilot’s   Indicator).   When in view, indicates loss of power to the gyro. (4)   Inclinometer. Indicates lateral acceleration (side-slip) of aircraft. c.   Each EADI and EHSI contains an inclinometer on the bottom of the bezel. 3C-18.  RADIO ALTIMETER (RA-315). a.   Description.      The   radio   altimeter   provides the  pilot  with  the  actual  altitude  of  the  aircraft  above ground  or  surface  level.    The  altitude  is  displayed  in the   lower   right-hand   corner   of   the   EADI   when   the aircraft  is  at  or  below  2500  feet  Above  Ground  Level