TM 1-1510-225-10 8-21 Do    not    turn    off    exterior    lights    until propeller rotation has stopped. 17.  Exterior lights – OFF. 18.  DC voltmeters – Check voltage. 19.  Overhead panel switches – As required. 20.  Oxygen system – Off. 21.  AVIONICS MASTER PWR – OFF. NOTE Wait until the gas generator speed of both engines  drops  below  10%  prior  to  turning off the MASTER SWITCH. 22.  MASTER SWITCH – OFF. 23.  Chocks – As required. 24.  Parking brake – As required. 25.  Control locks – As required. 8-46.  BEFORE LEAVING AIRCRAFT. 1.  Wheels – Chocked. NOTE Brakes should be released after chocks are in place (ramp conditions permitting). 2.  Parking brake – As required. 3.  Flight controls – Locked. 4.  Overhead flood lights – OFF. 5.  STANDBY PUMPS – OFF. 6.  Transponder – As required. 7.  COMSEC – Zeroize as required. 8.  Emergency exit lock – As required. 9.  Aft cabin light – OFF. 10.  Door light – OFF. CAUTION If  strong  winds  are  anticipated  while  the aircraft  is  unattended,  the  propellers  shall be   secured   to   prevent   windmilling   with zero engine oil pressure. 11.  Walk-around inspection – Complete. Conduct a thorough walk-around inspection, checking for damage, fluid leaks, and levels. Check that covers, tiedowns, restraints, and chocks are installed as required. 12.  Aircraft  forms  –  Complete.    In  addition  to established  requirements  for  reporting  any system  defects,  or  unusual  and  excessive operation  such  as  hard  landings,  etc.,  the flight  crew  will  also  make  entries  on  DA Form  2408-13-1  to  indicate  when  limits  in the Operator's Manual nave been exceeded. 13.  Aircraft secured – Check.  Lock cabin door as required. Section III.  INSTRUMENT FLIGHT 8-47.  GENERAL. This    aircraft    is    qualified    for    operation    in instrument   flight   meteorological   conditions.      Flight handling,  stability  characteristics,  and  range  are  the same   during   instrument   flight   conditions   as   when under visual flight conditions. 8-48.  INSTRUMENT FLIGHT PROCEDURES. Refer  to  FM  1-240,  FM  1-230,  FLIP,  AR  95-1, TC 1-218,   FAR   91   (subparts   A   and   B),   applicable foreign    government    regulations,    and    procedures described  in  this  manual.    Accomplish  all  instrument flight tasks in accordance with the appropriate ATM. Section IV.  FLIGHT CHARACTERISTICS 8-49.  STALLS. A   pre-stall   warning   in   the   form   of   very   light buffeting  can  be  felt  when  a  stall  is  approached.    A mechanical   warning   is   also   provided   by   a   warning horn.  The warning horn starts to alarm approximately 5 to 10 knots above stall speed with the aircraft in any configuration.    If  correct  stall  recovery  technique  is used, little altitude will be lost during the stall recovery. For  the  purpose  of  this  section,  the  term  "power-on" WARNING