AMS 274 Turbines Unit 3 Exam Review (Hancock) questions
and answers 2026\2027 A+ Grade
State three functions of the oil tanks overboard relief valve:
- correct answer 1. Maintains positive pressure
2. Vents to prevent tank failure
3. Allows depressurization of tank at shutdown
What is the function of the oil tanks dwell chamber?
- correct answer Separates air from the oil (bleeds it out from the scavenge system)
What is the position of the internal valves of the pressurizing and vent valves when the aircraft is on the
ground?
- correct answer Aneroid valve is open
What is the position of the internal valves of the pressurizing and vent valves when the aircraft is at 20k
ft?
- correct answer Aneroid begins to open at around 8000-10000 ft, and will be completely closed at
20000 ft
What is a "hot tank"?
- correct answer The cooler is located in the pressure subsystem
What is a "cold tank"?
- correct answer The cooler is located in the scavenge system
Explain trimming:
- correct answer Also known as tuning, is when you make adjustments to the fuel control system for idle
and max power (there are 2 adjustments)
, Explain the thermostatic valve position and flow of fuel and oil when the oil is cold in a fuel/oil cooler:
- correct answer The thermostatic valve is open and ONLY fuel is flowing
Explain the thermostatic valve position and flow of fuel and oil when the oil is hot in a fuel/oil cooler:
- correct answer The thermostatic valve is closed and forces oil through the cooler with the fuel (the two
mix and oil heats the fuel)
Oil jets:
- correct answer Fixed nozzles that apply constant flow to all the bearings (fixed nozzles used for this
reason)
Chip detector:
- correct answer Checks for the presence of ferrous material due to internal breakdown
What happens when ferrous pieces get into a chip detector?
- correct answer When chips get in they attach to the magnet and complete the circuit to the electrode
and cause a chip light to illuminate in the cockpit
Gas turbine engines require what kind of oil?
- correct answer Synthetic oil (cannot be interchanged with reciprocating engine oil)
When should the oil in turbines be serviced and why?
- correct answer Just after shutdown when the oil is still warm so you don't over-service the system
What else can you use to cool oil aside from fuel?
- correct answer RAM air
Delta P does what?
- correct answer Has a light that denotes an impending filter bypass. This allows oil to bypass the filter in
case of a clogging/oil is too cold
What is the main purpose of the P&V valve?
- correct answer To keep vent pressure constant to assure proper oil flow
and answers 2026\2027 A+ Grade
State three functions of the oil tanks overboard relief valve:
- correct answer 1. Maintains positive pressure
2. Vents to prevent tank failure
3. Allows depressurization of tank at shutdown
What is the function of the oil tanks dwell chamber?
- correct answer Separates air from the oil (bleeds it out from the scavenge system)
What is the position of the internal valves of the pressurizing and vent valves when the aircraft is on the
ground?
- correct answer Aneroid valve is open
What is the position of the internal valves of the pressurizing and vent valves when the aircraft is at 20k
ft?
- correct answer Aneroid begins to open at around 8000-10000 ft, and will be completely closed at
20000 ft
What is a "hot tank"?
- correct answer The cooler is located in the pressure subsystem
What is a "cold tank"?
- correct answer The cooler is located in the scavenge system
Explain trimming:
- correct answer Also known as tuning, is when you make adjustments to the fuel control system for idle
and max power (there are 2 adjustments)
, Explain the thermostatic valve position and flow of fuel and oil when the oil is cold in a fuel/oil cooler:
- correct answer The thermostatic valve is open and ONLY fuel is flowing
Explain the thermostatic valve position and flow of fuel and oil when the oil is hot in a fuel/oil cooler:
- correct answer The thermostatic valve is closed and forces oil through the cooler with the fuel (the two
mix and oil heats the fuel)
Oil jets:
- correct answer Fixed nozzles that apply constant flow to all the bearings (fixed nozzles used for this
reason)
Chip detector:
- correct answer Checks for the presence of ferrous material due to internal breakdown
What happens when ferrous pieces get into a chip detector?
- correct answer When chips get in they attach to the magnet and complete the circuit to the electrode
and cause a chip light to illuminate in the cockpit
Gas turbine engines require what kind of oil?
- correct answer Synthetic oil (cannot be interchanged with reciprocating engine oil)
When should the oil in turbines be serviced and why?
- correct answer Just after shutdown when the oil is still warm so you don't over-service the system
What else can you use to cool oil aside from fuel?
- correct answer RAM air
Delta P does what?
- correct answer Has a light that denotes an impending filter bypass. This allows oil to bypass the filter in
case of a clogging/oil is too cold
What is the main purpose of the P&V valve?
- correct answer To keep vent pressure constant to assure proper oil flow
