Pneumatics Flashcards
How is a leak detected in the cowls
By a pressure transducer
What is a APU interlock protection
Prevents APU from supplying air
If engine bleed source is open
AILC?
Anti-ice and leak detection controller
What does the AILC provide?
EICAS msgs and system control of the bleed air leak detection system
Wing anti-ice is divided into how many sections
Four loops
L/R FUSELAGE LOOPS
L/R WING LOOPS
How are the leading edges heated
Hot bleed air from the duct is released through piccolo tubes
What detects failures in wing anti-ice ducting
Dual loops
And
A skin temperature sensor in wing leading edge
ACSC ( air-conditioning system controller) provides what during starts?
Isol valve opens/closes automatically during starts
How many zones is the pneumatic system divided into
5
L BLEED R BLEED L COWL R COWL WING ANTI ICE
Low pressure air?
High pressure air?
6th stage
10th stage
What’s manages the distribution of bleed air?
2 ACSC’s
Air conditioning system controllers
APPCH BIT … Landing
When do bleeds switch from engine to APU if bleeds closed are needed for landing
APPCH BIT
Either engine available
FLAPS greater then 20 degrees
Or
Ldg gear down
What does AILC(anti-ice and leak detection controller) do. If leak is detected
Sends signal to close valves to isolate system
only for leaks not overheat.. Wing overheat
APPCH BIT … Takeoff
When do bleeds transfer from APU to the engines on take off if bleeds closed needed
Landing gear up
AND
flaps 20 or less
Tl out of toga
Does anything close automatically for a wing overheat
No
What prevents compressor surge for the APU
Surge control valve
What monitors the bleed system for leaks
AILC anti-ice in leak detection controller
Pneumatically operated aircraft systems include:
Engine starting
Cowl and wing anti-ice
Air-conditioning and pressurization
- managed by two air conditioning system controllers(ACSC)
Test
The ACSC Will open or close the HPV depending on the bleed air manifold pressure and aircraft system requirements
What’s modulates the APU bleed air to the load control valve
ECU
TEST
BLEED MISCONFIG. amber
Indicates on impossible bleed configuration in manual mode
The bleed air leak detection system monitors
The pneumatic and anti-ice ducting for high temperatures associated with the bleed air leakage
EICAS Messages and system control of the bleed air leak detection system is provided by
On anti-ice and leak detection controller
AILC
The bleed air leak detection system is divided into five zones
Left and right bleed zone
Left and right, cowl anti-ice zones when anti-ice zone.
( when anti-ice zone is subdivided into four loops… Left and right fuselage loops, left and right wing loops)
The wing anti-ice loops ducting is encased in a protective cover, if a leak occurs …
Holes in the protective cover direct the hot bleed air towards the sensing loops
The cowl anti-ice ducts located in the engine pylons consists of
Inner and outer ducts
Bleed Air For anti-icing travels through the inner duct
The area between the inner and outer duct is monitored by a pressure transducer
The pneumatic system is supplied bleed air pressure from
The engine compressors
For the APU compressor
Manifold pressure is regulated to
45 PSI by the pressure regulating shut off valve(PRSOV)