TM 1-1510-225-10 8A-14 * 8A-29.  TAXIING. CAUTION Never  taxi  with  a  flat  tire  or  a  flat  shock strut.      During   taxi   operations,   particular attention  should  be  given  to  propeller  tip clearance.      Extreme   caution   is   required when operating on unimproved or irregular surfaces   or   when   high   winds   exist.      If operations  produce  a  propeller  RPM  over 1600,  retard  propeller  levers  to  the  detent to  limit  RPM  to  1600  to  help  reduce  the possibility of ingestion of ground debris. 1.   Brakes – Check. 2.   Flight instruments – Check. 8A-30.  ENGINE RUNUP. 1.   Parking brake – As required. 2.   Manual prop feathering – Check. H   3.  AUTOFEATHER/AUTO   IGNITION  –   Check as required. a.  AUTO     IGNITION switches – ARM. IGNITION ON annunciators illuminated. b.  POWER levers – 500 ft-lb.  IGNITION ON annunciators extinguish. c.   AUTOFEATHER  switch  –  Hold  to  TEST. Both AUTOFEATHER annunciators illuminated. d.  POWER levers – Retard individually. (1)  Approximately 400 ft-lb torque, opposite  AUTOFEATHER  annunciator extinguished, IGNITION ON annunciator illuminated. (2)  Approximately   260   ft-lb   torque,   both AUTOFEATHER annunciators extinguished  (prop  begins  to  feather). Both IGNITION ON annunciators illuminated. NOTE AUTOFEATHER annunciators will illuminate     and     extinguish with each fluctuation    of    torque    as    the    propeller attempts to feather. (3)  Return POWER levers to approximately 500 ft-lb torque. e.  Repeat procedure with other engine. f.    POWER levers – IDLE. g.  AUTOFEATHER switch – ARM. h.  AUTO IGNITION switches – Off. H 4.   Overspeed   governors   and   rudder   boost   – Check as required. a.  RUDDER BOOST switch – On. b.  PROP levers – HIGH RPM. c.   PROP GOV TEST  switch  –  Hold  in  TEST position. d.  Left     POWER     lever     –     Increase     until propeller is stabilized at 1830 – 1910 RPM. Continue to increase until rudder movement   is   noted.      Observe   ITT   and torque limits; and PROP remains stabilized at 1830 – 1910 RPM. e.  POWER lever – Retard to IDLE. f.    Repeat   steps   c,   d,   and   e   for   the   right engine. H 5.   Primary governors – Check as required. a.  POWER levers – Set 1800 RPM. b.  PROP    levers    –    Retard    to    FEATHER detent.    Note  propellers  stabilize  between 1600 and 1640 RPM. c.   PROP    levers    –    HIGH    RPM.        Note propellers return to 1800 RPM. H   6.  ICE VANES – Check. a.  ICE VANES – EXTEND. (1)  Both advisory lights illuminated. (2)  Both bypass doors extended. (3)  Maximum    time    for    (1)    and    (2)    is 15 seconds. b.  ICE VANES –RETRACT. (1)  Both advisory lights extinguish. (2)  Both bypass doors retracted. (3)  Maximum    time    for    (1)    and    (2)    is 15 seconds. 7.   CONDITION levers – HIGH IDLE. 8.   POWER levers – IDLE.