TM 55-4920-328-13 meter (38) exceeds the maximum specified temperature,  immediately  abort  the  start  by  depressing the switches and switchlight unit a second time. 3-9.  Hydraulic Start Procedures. WARNING Ear    protection    must    be    worn    by operating personnel outside the control cab when the engine Is being operated.      Failure   to   observe   this warning will result in damage to and eventual loss of hearing. Accomplish     the     start     of     a     gas     turbine     engine (equipped  with  a  hydraulic  starter)  in  accordance  with the following: a.  For starting a T55 engine, position the relief valve selector switch (13, figure 1-8) to the down position.  For starting   a   T73   engine,   position   the   switch   to   the   up position.    Prior  to  starting,  ensure  that  the  switch  is  in the appropriate position. b.    Position  and  hold  the  spring-loaded  START/RUN switch   (4,   figure   1-26)   in   START   until   the   gasoline engine  starts,  then  position  the  switch  to  RUN.    This action will start the gasoline engine in the hydraulic start system (figure 1-8).  Allow at least a two-minute warmup prior  to  energizing  the  hydraulic  starter  on  the  engine under test, then adjust the engine speed using the HYD STARTER ENGINE SPEED switch (5, figure 1-26). c.    Note  the  pressure  buildup  on  the  supply  pressure gage   (11,   figure   1-8).      During   the   foregoing   action, hydraulic    fluid    is    bypassed    to    return    and    system pressure will be below the operating pressures required to drive the hydraulic starter on the gas turbine engine. d.  Depress switch No. 30 on the data selector 1A2 (7, figure 1-22), then depress the ENGINE FUEL SOLENOID   switchlight   (30,   figure   1-24).      Verify   an indication of fuel pressure on the FUEL FLOW monitor unit (16, figure 1-23). WARNING If  the  temperature  Indicated  on  the EXHAUST    GAS    TEMP    meter    (38, figure   1-24)   exceeds   the   specified limit after lightoff, immediately depress the ENGINE FUEL SOLENOID switchlight unit (30), START   switch   (31),   and   IGNITION switch (32) on operator's panel 3A3 a second time.  This action will cut off fuel  and  ignition  and  will  allow  the EGT to drop.  Failure to observe this warning  will  result  In  damage  to  the equipment  and  may  cause  Injury  to operating personnel. e.    Simultaneously  depress  the  START  switch  (31), IGNITION  switch  (32)  and  TIMER  START  switchlight unit  (35).    Hold  all  switches  except  timer  in  energized position   until   lightoff.      If   lightoff   occurs   within   the maximum  specified  starting  time,  release  the  starting and   timing   switches   and   observe   rising   EGT   on   the EXHAUST  GAS  TEMP  meter  (38).    If  the  HYD  TEMP HIGH  indicator  (2,  figure  1-26)  comes  on,  deenergize the starting and timing switches and allow the hydraulic fluid   to   cool   before   a   restart.      One   restart   may   be attempted.        If    lightoff    does    not    occur    at    restart, deenergize   all   systems   and   troubleshoot   the   unit   as specified in chapter 5 of this technical manual. f.  For T73 engine test only, advance the NI throttle to the     idle     speed     factor     recorded     in     Section     VIII, Installation   of   T73   Engine   for   Testing,   paragraph   2- 59au. g.      At   lightoff,   monitor   the   EXHAUST   GAS   TEMP meter (38, figure 1-24) to determine that the temperature     observed     does     not     exceed     specified temperature limits. h.    Monitor  the  instrumentation  and  note  that  engine test  parameters  agree  with  the  applicable  engine  test procedures, then accomplish the procedures outlined in paragraph 3-10. i.  Deenergize hydraulic start system (4, figure 1-26). 3-10