ENGINE START PANEL

Question 1

ENGINE START Switch

• 4 positions / 2 switches -

GRD

OFF

CONT

FLT

Answer 1

GRD: (operated on the ground AND in flight)

• solenoid held - spring loaded to OFF
  
  • Opens Start Valve [START VALVE OPEN] comes on
  • Closes ENG Bleed Valve
  • for GROUND starts:
    
    • Arms selected igniters to provide ignition when eng start lever moved to IDLE
  • for INFLIGHT starts:
    
    • Arms BOTH igniters to provide ignition when eng start lever moved to IDLE
• releases to OFF at START VALVE cutout (56% N2)

OFF:

• ignition normally off
• Both igniters activated when engine start lever is in IDLE and
  
  • uncommanded rapid decrease in N2 occurs - OR -
  • N2 is between 57-50% - OR -
  • Inflight and N2 is between IDLE and 5%

CONT:

• provides ignition to selected igniter when engine is operating AND eng START LEVER is in IDLE
• INFLIGHT (only): provides ignition to BOTH ignitors when N2 is below idle and START LEVER is in IDLE
• Normal Uses:
  
  • Takeoff and Landing
  • Emergency Descent
  • Eng Anti-Ice
  • Moderate to Heavy Rain, Hail or Sleet
  • Inflight engine start if N2 < 8%

FLT:

• provides ignition through BOTH igniters when the Start Lever is in IDLE
• bypasses the Ignition Select Switch
• Normal Uses:
  
  • Inflight Windmill Start
  • High Engine Vibration
  • Fan Ice removal
  • Severe Turbulance
  • Loss of Thrust on Both Engines
  • Volcanic Ash

Question 2

IGNITION SELECT Switch

Answer 2

IGN L: selects left ignitor for use on BOTH engines

BOTH: selects BOTH ignitors for use on BOTH engines

IGN R: selects RIGHT ignitor for use on BOTH engines (Standby AC Bus)

Question 3

1SP questions on the Start Switches.

1. What are we doing by putting the start switch in the ground position?
2. What is the difference between ground and continuous?
3. What is the difference between continous and flight?
4. What is the power source of the right ignitor?
5. Why is this so important (the above source?)

Answer 3

1. the only thing we are doing is opening the start valve.
2. in ground you will open the start valve, in continuous you bypass the start valve
3. in CONT you will have continuous ignition depending on which ignitor you select (L/R/Both) in FLT you are going to get both ignitors regardless of the position of the ignition switch
4. AC Standby bus. (right) The left is powered by the respective transfer bus.
5. because you are checking the AC standby bus so that incase inflight you lose both generators the only ignitor you are going to have is the right ignitor.