AMS 274 UNIT 4 | QUESTIONS AND ANSWERS | 2026 UPDATE | 100% CORRECT
A typical Gear ratio for an air turbine starter is 25:1. If the turbine is rotating @ 80,000 RPM's, what
would the input RPM be to the gear box? - (ANSWER)3,200 RPM
With a variable vane system when will the vanes be most closed? - (ANSWER)at Low RPM
What happens if the vanes are stuck in the open position? - (ANSWER)Engine will stall in low power
A clicking noise heard from an air turbine starter on engine coast down is a result of what? -
(ANSWER)Pawls re-engaging and riding the ratchet in case we need a re-start
Which igniter plug requires special handling due to semi-conductor material? - (ANSWER)Low voltage
shunted surface gap (Self Ionizing)
What does the semi conductor material do when its HOT and COLD? - (ANSWER)Cold- Conducts
Hot- Isolates
What is autoignition and what does it sense? - (ANSWER)Ensures instantaneous igniton if an engine
loses power. Senses Torque, Oil Pressure, and loss of Compressure dischatge pressure
What positions are fail type anti-ice valves in? - (ANSWER)Powered closed and spring loaded open
What instrument indication would you most likely see when engine anti-ice is turned on? -
(ANSWER)Slight Rise in EGT (10 Degrees)
Starting sequence - (ANSWER)Starter, Ignition, Fuel
When do you disengage the starter? - (ANSWER)When it reaches self accelerating speed
Where is the Pressure Regulating and Shutoff valve located? - (ANSWER)Pneumatic starter Unit
A typical Gear ratio for an air turbine starter is 25:1. If the turbine is rotating @ 80,000 RPM's, what
would the input RPM be to the gear box? - (ANSWER)3,200 RPM
With a variable vane system when will the vanes be most closed? - (ANSWER)at Low RPM
What happens if the vanes are stuck in the open position? - (ANSWER)Engine will stall in low power
A clicking noise heard from an air turbine starter on engine coast down is a result of what? -
(ANSWER)Pawls re-engaging and riding the ratchet in case we need a re-start
Which igniter plug requires special handling due to semi-conductor material? - (ANSWER)Low voltage
shunted surface gap (Self Ionizing)
What does the semi conductor material do when its HOT and COLD? - (ANSWER)Cold- Conducts
Hot- Isolates
What is autoignition and what does it sense? - (ANSWER)Ensures instantaneous igniton if an engine
loses power. Senses Torque, Oil Pressure, and loss of Compressure dischatge pressure
What positions are fail type anti-ice valves in? - (ANSWER)Powered closed and spring loaded open
What instrument indication would you most likely see when engine anti-ice is turned on? -
(ANSWER)Slight Rise in EGT (10 Degrees)
Starting sequence - (ANSWER)Starter, Ignition, Fuel
When do you disengage the starter? - (ANSWER)When it reaches self accelerating speed
Where is the Pressure Regulating and Shutoff valve located? - (ANSWER)Pneumatic starter Unit
