TM  1-1520-240-10 2-3-10            Figure  2-3-7.  DECU Panel  714A percent N1 then release the ENG START switch. The automatic start sequence has been energized and FA- DEC  will  complete  the  start.  When  an  engine  start  is energized, FADEC turns on the engine start solenoid to introduce fuel flow and energize the engine igniters. Suc- cessful engine ignition is immediately indicated to FA- DEC by an increase of PTIT or compressor speed (N1). Engine  temperature  is  monitored  throughout  the  se- quence and will result in a fuel flow reduction if the tem- perature exceeds 650_C with a full cutback to minimum flow  limit  at  760_C.  The  starter  motor  and  igniter  are automatically turned off when N1 speed exceeds 48 per- cent. Ground idle is 50 to 59 percent and is corrected for temperature. The engine is allowed to take 45 seconds to stabilize at ground idle. 2-3-36.  Engine Start Abort.  714A PTIT above 816_C will cause immediate fuel shutoff to below minimum fuel flow. The ECL must be retarded to STOP to achieve total fuel shutoff. A start abort results in the ENG 1 (2) FAIL warning to be illuminated until the abort is reset by moving the ECL to STOP. 2-3-37.  Starting in Reversionary Mode.  714A The initial start sequence in reversionary mode is the same as in primary mode except, when N1 reaches 8 percent, the control system turns on the engine start fuel solenoid to provide an initial altitude biased fuel flow and activates the igniters and latches the starter motor. The pilot can modulate fuel flow to the engine with ECL to start the engine at a desired acceleration rate. Tempera- ture and temperature rate limiters are the same as in primary  mode  except  that  the  over  temperature  start abort facility is not provided. Alternate Reversionary Starting. For most conditions, a start is successfully completed with the ECL held at the GND position. However, if the engine fails to start due to either a rich or lean hung start condition, the pilot may use the ECL to increase or decrease the start flow as required to complete a successful start. a. Reversionary Rich Hung Start. A rich hung start is characterized by N1 holding at about 40 percent and PTIT climbing above 600_C. If a rich hung start is experi- enced. (1) Set the affected engine ECL to STOP. (2) Allow PTIT to decay to 260_C or below (mo- tor engine as required). (3) Check N1 0 percent. (4) Advance  ECL  half  the  distance  between STOP and GND (15_). (5) Motor engine using ENG START switch until 10% N1 and then release switch. (6) After engine ignition (PTIT rising), slowly ad- vance ECL to GND. Check that N1 is stabilized at ground idle. b. Reversionary Lean Hung Start. A lean hung start is characterized by N1 hanging approximately 30 percent and PTIT remaining below 500_C. If a lean hung start is experienced. (1) Slowly  advance  the  hung  engine  ECL  to achieve acceleration (maximum of one-third travel from GND to FLT). (2) Retard the ECL to GROUND as ground idle speed  is  approached.  Check  that  N1  is  stabilized  at ground idle. 2-3-38.  Starting    Cycle,    Aborting    and    Motoring. 714A A starting cycle can be aborted at any time by moving the ECL to STOP. 2-3-39.  Power Assurance Test Switch.  714A The  primary  FADEC will  perform  a  BIT  whenever  the PWR ASSURANCE TEST switch has been place to the desired engine position. The switch is located below the maintenance panel at station 524. The switch is label 1/OFF/2 and spring loaded to OFF. The results of the test are displayed in the DECU BIT window. 2-3-40.  Engine Wash System.  714A The helicopter is equipped with an engine wash system for each engine. Air and water connections are externally mounted inboard of each engine work platform. A series of spray nozzles are installed at the engine inlet and air lines are routed to the bleed band actuator.