FAA ATP Powerplant & Systems Questions

Under normal operating conditions, which combination of MAP and RPM produce the most severe wear, fatigue, and damage to high performance reciprocating engines?

• High RPM and low MAP.
• Low RPM and high MAP.
• High RPM and high MAP.

Explanation: The most severe rate of wear and fatigue damage occurs at high RPM and low MAP. Answer (B) is incorrect because while low RPM and high MAP produce severe wear to high performance reciprocating engines, the most damage is done by high RPM and low manifold pressure. Answer (C) is incorrect because a high RPM and a low MAP produce the most severe wear to high performance reciprocating engines.

FAA Airplane Flying Handbook - Reciprocating Engine Operation

Which type of compressor stall has the greatest potential for severe engine damage?

• Intermittent 'backfire' stall.
• Transient 'backfire' stall.
• Steady, continuous flow reversal stall.

Explanation: If a compressor stall is transient and intermittent, the indication will be an intermittent 'bang' as backfire and flow reversal take place. If the stall develops and becomes steady, strong vibration and a loud roar develop from the continuous flow reversal. The possibility of damage is immediate from a steady stall. Recovery must be accomplished quickly by reducing throttle setting, lowering the airplane angle of attack, and increasing airspeed.

FAA Airplane Flying Handbook - Compressor Stalls

What characterizes a transient compressor stall?

• Loud, steady roar accompanied by heavy shuddering.
• Sudden loss of thrust accompanied by a loud whine.
• Intermittent 'bang,' as backfires and flow reversals take place.

Explanation: If a compressor stall is transient and intermittent, the indication will be an intermittent 'bang' as backfire and flow reversal take place. If the stall develops and becomes steady, strong vibration and a loud roar develop from the continuous flow reversal. The possibility of damage is immediate from a steady stall. Recovery must be accomplished quickly by reducing throttle setting, lowering the airplane angle of attack, and increasing airspeed. Answer (A) is incorrect because this describes a developed and steady stall. Answer (B) is incorrect because a transient stall is characterized by an intermittent 'bang.'

FAA Airplane Flying Handbook - Compressor Stalls

What indicates that a compressor stall has developed and become steady?

• Strong vibrations and loud roar.
• Occasional loud 'bang' and flow reversal.
• Complete loss of power with severe reduction in airspeed.

Explanation: If a compressor stall is transient and intermittent, the indication will be an intermittent 'bang' as backfire and flow reversal take place. If the stall develops and becomes steady, strong vibration and a loud roar develop from the continuous flow reversal. The possibility of damage is immediate from a steady stall. Recovery must be accomplished quickly by reducing throttle setting, lowering the airplane angle of attack, and increasing airspeed. Answer (B) is incorrect because this describes an indication of a transient stall. Answer (C) is incorrect because a compressor stall will not cause a complete loss of power.

FAA Airplane Flying Handbook - Compressor Stalls

Minimum specific fuel consumption of the turboprop engine is normally available in which altitude range?

• 10,000 feet to 25,000 feet.
• 25,000 feet to the tropopause.
• The tropopause to 45,000 feet.

Explanation: Minimum specific fuel consumption of a turboprop engine will be obtained in an altitude range of 25,000 to 35,000 feet. The tropopause will be in the neighborhood of 35,000 feet depending on the season and latitude.

FAA Airplane Flying Handbook - Turboprop Engines

How are turbine engines classified?

• The type of compressor or combination of compressors they use.
• The method in which the air/fuel mixture is ignited.
• The flow of air through the engine and how power is produced.

Explanation: Turbine engines are classified by the type of compressors they use -- centrifugal flow, axial flow, and centrifugal-axial flow.

FAA Airplane Flying Handbook - Turbine Engine Classification

Which place in the turbojet engine is subjected to the highest temperature?

• Compressor discharge.
• Fuel spray nozzles.
• Turbine inlet.

Explanation: The highest temperatures in any turbine engine will occur at the turbine inlet. This TIT (Turbine Inlet Temperature) is usually the limiting factor in the engine operation.

FAA Airplane Flying Handbook - Turbine Engines

What effect does high relative humidity have upon the maximum power output of modern aircraft engines?

• Neither turbojet nor reciprocating engines are affected.
• Reciprocating engines will experience a significant loss of BHP.
• Turbojet engines will experience a significant loss of thrust.

Explanation: While turbojet engines are almost unaffected by high relative humidity, reciprocating engines will experience a significant loss of BHP (Brake Horsepower). Answer (A) is incorrect because both reciprocating and turbojet engines are affected by high relative humidity to some degree. Answer (C) is incorrect because turbojet engines will have a negligible loss of thrust.

FAA Airplane Flying Handbook - Reciprocating Engines