AMS 274 Turbines Final UPDATED Exam Questions and
CORRECT Answers
If the anti-ice air valve is open what happens to EGT? - -EGT increases (tachometer and
EPR also shift)
-How do you calculate EPR? - -Turbine discharge/Compressor inlet pressure
-What are the most common type of thermocouples used? - -Chromel/Alumel (CA)
-What do the older style APUs have in them? - -Governors
-What is the typical gear down ratio for pneumatic starters? - -25:1
-What is the starting sequence for turbine engines? - -Starter --> Ignition --> Fuel
-you hear a clicking noise from the pneumatic starter it indicates: - -The pawls re-engaging
(normal)
-Typical air flow in a pneumatic starter: - -Air flows into the starter --> Stator vanes
(designed to choke in order to prevent overspeed) --> Turbine
-What was Whittle famous for? - -Invented the jet engine
-What are the 4 types of gas turbines and typical aircraft they are found on: - -1. Turbojet
(supersonic)
2. Turbofan (large commercial)
3. Turboprop (larger GA)
4. Turboshaft (helicopters)
-What is the Brayton Cyle? - -thermodynamic cycle that explains how gas turbine engines
run
-Bernoulli's principle: - -As the velocity of a fluid increases, the pressure exerted by the
fluid decreases (convergent ducts: velocity increases and pressure decreases/divergent
ducts: velocity decreases and pressure increases)
-What company produced the first gas turbine engine in the U.S.? - -General Electric
-In a split-spool/dual-spool/twin-spool turbine, what drives what? - -The low-speed
turbine drives the first compressor
The high speed turbine drives the second compressor
-What is typically found in a turboshaft engine? - -A power turbine
CORRECT Answers
If the anti-ice air valve is open what happens to EGT? - -EGT increases (tachometer and
EPR also shift)
-How do you calculate EPR? - -Turbine discharge/Compressor inlet pressure
-What are the most common type of thermocouples used? - -Chromel/Alumel (CA)
-What do the older style APUs have in them? - -Governors
-What is the typical gear down ratio for pneumatic starters? - -25:1
-What is the starting sequence for turbine engines? - -Starter --> Ignition --> Fuel
-you hear a clicking noise from the pneumatic starter it indicates: - -The pawls re-engaging
(normal)
-Typical air flow in a pneumatic starter: - -Air flows into the starter --> Stator vanes
(designed to choke in order to prevent overspeed) --> Turbine
-What was Whittle famous for? - -Invented the jet engine
-What are the 4 types of gas turbines and typical aircraft they are found on: - -1. Turbojet
(supersonic)
2. Turbofan (large commercial)
3. Turboprop (larger GA)
4. Turboshaft (helicopters)
-What is the Brayton Cyle? - -thermodynamic cycle that explains how gas turbine engines
run
-Bernoulli's principle: - -As the velocity of a fluid increases, the pressure exerted by the
fluid decreases (convergent ducts: velocity increases and pressure decreases/divergent
ducts: velocity decreases and pressure increases)
-What company produced the first gas turbine engine in the U.S.? - -General Electric
-In a split-spool/dual-spool/twin-spool turbine, what drives what? - -The low-speed
turbine drives the first compressor
The high speed turbine drives the second compressor
-What is typically found in a turboshaft engine? - -A power turbine
