Aircraft Pneumatic Systems and Aircraft Environmental Control Systems Flashcards
Which on board systems use pneumatics?
Aircraft conditioning, Pressurisation/Cargo compartment heating Deicing- Anti-icing Defrosting Pressurisation of oil/fuel/water reservoirs Ventilation of fuel tanks Transfer of fuel Transfer of fuel Operation of actuators
What is the main source of air for pneumatics, and where does it come from?
Bleed air from the 2nd stage(low/medium pressure) and 5th/6th exit stage (high pressure) of the compressor
How does a compressor work and what is its purpose?
It produces pressure in the air. It Works by adding KE into a flow of air, speeding it up, and then slowing it down with stators, converting this KE into Potential enters, PE.
What is the purpose of a turbine, and explain how it works
The reverse of a compressor. It extracts useful work from a flow. A set of static guide vanes accelerates and adds swirl to the flow and then directs it to the next set of blades to take energy out
How should we start a main aircraft jet engine with pneumatic system?
1) BAttery supplies power to the APU starter (DC), while main aircraft generators are disconnected
2) APU generates compressed air that is injected into the jet engine turbine module (electric generator not connected)
3) After successful engine start, electric generators and hydraulic pumps engaged
What is the purpose of Environmental Control Systems?
Ensures that environment of cabin/cockpit is safe without health hazards and comfortable in all flight conditions
What are the uses of ECS on board of the aircraft?
Cabin A/C
Cabin Pressurisation
Cargo compartment ventilation and heating
What is the equivalent altitude from cabin pressure?
8000ft or 2400m
What is the source of cabin air?
Pneumatic system
Name 1 type of thermodynamic cycle for supply of cabin air
Inverted Joule
Bootstrap
How can we control oxygen supply for passengers in a) normal operations b) emergency situations?
a) Increase Pressure to comfortable levels(alt. 8000ft or 2400m)
b) Oxygen masks and then equalising pressure internally with externally
