S Pneumatic Systems Flashcards
1
Q
What are the advantages of a pneumatic system?
A
- Air is readily available
- Pneumatic system can be light weight
- Piston can generate compressed air using compressor
- Gas turbines have a bleed air system from the compressor
- Smaller fire risk
- Compressible - can be a shock absorber
2
Q
What are the disadvantages of the pneumatic system?
A
- Can’t match speed of response of a hydraulic system
- Difficult to seal at high pressure
- Difficult to trace leaks
- Can be extremely hot
- Bleeding air from the engine reduces its efficiency
3
Q
What uses the pneumatic system in a light aircraft?
A
- Gyroscopic instruments
4
Q
What are the 3 sources of air for a gas turbine?
A
- Bleed air from the main engines
- Compressed air from the APU
- Compressed air from a GPU
5
Q
How do you solve the issue of pressure variations as engine RPM changes?
A
Take air from different sources at different times
- Intermediate compressor
- High pressure compressor
6
Q
How do you solve the issue of high temperature of bleed air?
A
Cooled before use
7
Q
What does a HPSOV do in the bleed air system?
A
Limits pressure to 100psi
8
Q
What does the PRSOV do in the bleed air system?
A
Reduces pressure to 40psi
9
Q
What information is made available to flight crew regarding the pneumatic system?
A
- Temperature
- Pressure
- Valve position
10
Q
What are the typical bleed air malfunctions?
A
- Over temperature
- Over pressure
- Low pressure
- Overheat/duct leak
