SYSTEMS - Engine Bleed Air 747 Exam
Questions with Correct Answers
Under what conditions would High Pressure (HP) air be used? (FCOM 2; 2.40.1)
Correct Answer 1. Descent
2. Other low power setting operations
Under what conditions would intermediate pressure (IP) air be used? (FCOM 2; 2.40.1)
Correct Answer High power setting operations
The engine bleed air switches control which valves by system logic, when bleed air
pressure is available? (FCOM 2; 2.40.1; 2.10.25) Correct Answer 1. Engine bleed air
valve
2. PRV
3. HP bleed valve
Describe the general function of pressure regulating valve (PRV) (FCOM 2; 2.40.1;
2.40.2) Correct Answer Prevents damage to ducting and equipment downstream, the
PRV limits bleed air pressure
How are the engine bleed air valves actuated, and when do they open for forward flow?
(FCOM 2; 2.40.1) Correct Answer 1. The bleed air valves are pressure actuated
2. They remain closed until engine bleed air pressure causes forward flow
With the HP valve failed open and the respective bleed air switch OFF, will nacelle anti-
ice be available? (FCOM 2; 2.40.2) Correct Answer No
An engine bleed air system (SYS) FAULT light indicates what? (FCOM 2; 2.10.25)
Correct Answer 1. Bleed air overheat
2. Bleed air overpressure
3. HP Bleed valve open when commanded closed
4. PRV open when commanded closed
What does a bleed duct isolation (ISLN) VALVE light indicate (amber)? (FCOM 2;
2.10.24) Correct Answer Isolation valve position disagrees with switch position
What prevents reverse air flow into the engine compressor sections during engine start?
(FCOM 2; 2.40.2) Correct Answer The PRV is positively closed
What happens if the engine start valve fails to close? (FCOM 2; 2.40.2) Correct Answer
1. Bleed air is isolated from the engine starter
2. The PRV remains closed
3. The engine bleed air valve remains closed
Questions with Correct Answers
Under what conditions would High Pressure (HP) air be used? (FCOM 2; 2.40.1)
Correct Answer 1. Descent
2. Other low power setting operations
Under what conditions would intermediate pressure (IP) air be used? (FCOM 2; 2.40.1)
Correct Answer High power setting operations
The engine bleed air switches control which valves by system logic, when bleed air
pressure is available? (FCOM 2; 2.40.1; 2.10.25) Correct Answer 1. Engine bleed air
valve
2. PRV
3. HP bleed valve
Describe the general function of pressure regulating valve (PRV) (FCOM 2; 2.40.1;
2.40.2) Correct Answer Prevents damage to ducting and equipment downstream, the
PRV limits bleed air pressure
How are the engine bleed air valves actuated, and when do they open for forward flow?
(FCOM 2; 2.40.1) Correct Answer 1. The bleed air valves are pressure actuated
2. They remain closed until engine bleed air pressure causes forward flow
With the HP valve failed open and the respective bleed air switch OFF, will nacelle anti-
ice be available? (FCOM 2; 2.40.2) Correct Answer No
An engine bleed air system (SYS) FAULT light indicates what? (FCOM 2; 2.10.25)
Correct Answer 1. Bleed air overheat
2. Bleed air overpressure
3. HP Bleed valve open when commanded closed
4. PRV open when commanded closed
What does a bleed duct isolation (ISLN) VALVE light indicate (amber)? (FCOM 2;
2.10.24) Correct Answer Isolation valve position disagrees with switch position
What prevents reverse air flow into the engine compressor sections during engine start?
(FCOM 2; 2.40.2) Correct Answer The PRV is positively closed
What happens if the engine start valve fails to close? (FCOM 2; 2.40.2) Correct Answer
1. Bleed air is isolated from the engine starter
2. The PRV remains closed
3. The engine bleed air valve remains closed
