AMS 274 UNIT 3 Exam Review questions and answers
2026\2027 A+ Grade
What is the primary purpose of a lubricant?
- correct answer To reduce friction between moving parts.
Why are synthetic lubricants used in turbine engines instead of petroleum-based ones?
- correct answer Because turbines require oils that meet specific viscosity and temperature demands
better achieved by synthetics.
What are desirable characteristics of synthetic lubricants?
- correct answer Low volatility, anti-foaming quality, low lacquer and coke deposits, high flash point, low
pour point, strong film strength, wide temperature range, and high viscosity index.
Why is low volatility important in turbine lubricants?
- correct answer To minimize evaporation at high altitudes.
What does anti-foaming quality provide in lubricants?
- correct answer More positive and reliable lubrication.
What does low lacquer and coke deposit formation prevent?
- correct answer The buildup of solid particles within the oil system.
What is the flash point of oil?
- correct answer The temperature at which oil gives off flammable vapors that will ignite near a flame
source.
What is the pour point of oil?
- correct answer The lowest temperature at which the oil will flow under gravity.
, What does 'film strength' refer to in oil?
- correct answer The oil’s cohesion and adhesionâ€"its ability to stick together and to surfaces under
load.
What temperature range can synthetic turbine oils operate in?
- correct answer Approximately â€"60°F to +400°F, with no preheat needed to about â€"40°F.
What does a high viscosity index indicate?
- correct answer The oil maintains its viscosity better when heated to operating temperature.
Can synthetic oils be mixed with petroleum-based oils?
- correct answer No, they are incompatible and should not be mixed.
How is viscosity index determined?
- correct answer By measuring viscosity changes when the lubricant is heated to two different
temperatures.
What do high viscosity index oils demonstrate?
- correct answer Minimal viscosity change with temperature variation.
What does the SAE number indicate in oils?
- correct answer Only the viscosity gradeâ€"not the oil’s quality.
What should be done if incompatible oils are accidentally mixed?
- correct answer Drain and flush the oil system before refilling.
When should oil be serviced?
- correct answer Just after engine shutdown while the oil is still warm.
Who dictates oil handling, storage, and disposal?
- correct answer Federal, State, and Local regulations, as well as employer policies.
2026\2027 A+ Grade
What is the primary purpose of a lubricant?
- correct answer To reduce friction between moving parts.
Why are synthetic lubricants used in turbine engines instead of petroleum-based ones?
- correct answer Because turbines require oils that meet specific viscosity and temperature demands
better achieved by synthetics.
What are desirable characteristics of synthetic lubricants?
- correct answer Low volatility, anti-foaming quality, low lacquer and coke deposits, high flash point, low
pour point, strong film strength, wide temperature range, and high viscosity index.
Why is low volatility important in turbine lubricants?
- correct answer To minimize evaporation at high altitudes.
What does anti-foaming quality provide in lubricants?
- correct answer More positive and reliable lubrication.
What does low lacquer and coke deposit formation prevent?
- correct answer The buildup of solid particles within the oil system.
What is the flash point of oil?
- correct answer The temperature at which oil gives off flammable vapors that will ignite near a flame
source.
What is the pour point of oil?
- correct answer The lowest temperature at which the oil will flow under gravity.
, What does 'film strength' refer to in oil?
- correct answer The oil’s cohesion and adhesionâ€"its ability to stick together and to surfaces under
load.
What temperature range can synthetic turbine oils operate in?
- correct answer Approximately â€"60°F to +400°F, with no preheat needed to about â€"40°F.
What does a high viscosity index indicate?
- correct answer The oil maintains its viscosity better when heated to operating temperature.
Can synthetic oils be mixed with petroleum-based oils?
- correct answer No, they are incompatible and should not be mixed.
How is viscosity index determined?
- correct answer By measuring viscosity changes when the lubricant is heated to two different
temperatures.
What do high viscosity index oils demonstrate?
- correct answer Minimal viscosity change with temperature variation.
What does the SAE number indicate in oils?
- correct answer Only the viscosity gradeâ€"not the oil’s quality.
What should be done if incompatible oils are accidentally mixed?
- correct answer Drain and flush the oil system before refilling.
When should oil be serviced?
- correct answer Just after engine shutdown while the oil is still warm.
Who dictates oil handling, storage, and disposal?
- correct answer Federal, State, and Local regulations, as well as employer policies.
