Section 09 - Pneumatics

Question 1

What aircraft systems use bleed air from the engines and/or APU?

Answer 1

Engine starting, air conditioning, cowl & wing anti-ice protection, pressurization, door seals

Question 2

A red “AFT EQUIP HOT” CAS message indicates high temperatures exist in the tail compartment. How is the faulty side identified?

Answer 2

Check high TGT, high fuel flow, low EPR or low (abnormal) bleed pressure readings

Question 3

What actions would cause the isolation valve to open?

Answer 3

The isolation valve switch is selected to OPEN, the APU air switch is selected ON (ground only), or if the MASTER START or CRANK switch is selected ON (ground only)

Question 4

An external air connection enters through the left side of the bleed manifold. How is it introduced to the right manifold?

Answer 4

By opening the isolation valve

Question 5

What is the function of the RAM AIR switch?

Answer 5

Turns OFF both air conditioning packs, and allows ambient air into the cabin when the pressure vessel completely depressurizes

Question 6

How is the engine bleed air cooled?

Answer 6

During high demand conditions, LP fan air moves through a heat exchanger (pre-cooler) in the engine pylon

Question 7

What is a consideration for bleed air operation above 41,000 feet?

Answer 7

The bleed air must be turned on and either respective air conditioning pack or the cowl anti-ice must be on for each engine