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
What does the PRSV do? (Pressure Regulating, and Shutoff valve) Answer -
controls airflow to the pneumatic starter
What parameter is the most critical to observe? Answer - TIT
What indicates a successful start on a turbine engine? Answer - Rise in EGT
At what RPM is a stall most likely to occur? Answer - Low-Medium
When are the bleeds open? Answer - at Low power
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
What does the PRSV do? (Pressure Regulating, and Shutoff valve) Answer -
controls airflow to the pneumatic starter
What parameter is the most critical to observe? Answer - TIT
What indicates a successful start on a turbine engine? Answer - Rise in EGT
At what RPM is a stall most likely to occur? Answer - Low-Medium
When are the bleeds open? Answer - at Low power
