737 - Air Systems

What are the possible sources of air for the bleed air system on the Boeing 737-800?

• Engines, APU, external air cart/source
• Engines, batteries, external air cart/source
• APU, batteries, external air cart/source
• Engines, APU, batteries

Answer explanation

Air for the bleed air system can be supplied by the engines, APU, or an external air cart/source.

Which systems rely on the bleed air system for operation on the Boeing 737-800?

• Air conditioning, pressurization, wing and engine thermal anti-icing
• Engine starting, hydraulic reservoirs pressurization, water tank pressurization
• Nitrogen Generation System, water tank pressurization, engine starting
• All of the above

Answer explanation

The bleed air system supports air conditioning/pressurization, wing and engine thermal anti-icing, engine starting, hydraulic reservoirs pressurization, and water tank pressurization.

From which stages of the compressor section is engine bleed air obtained on the Boeing 737-800?

• 3rd and 7th stages
• 4th and 8th stages
• 5th and 9th stages
• 6th and 10th stages

Answer explanation

Engine bleed air is obtained from the 5th and 9th stages of the compressor section.

What is the function of the engine bleed air valve on the Boeing 737-800?

• To act as a shutoff valve only
• To act as a pressure regulator only
• To act as both a pressure regulator and shutoff valve
• To act as a temperature regulator

Answer explanation

The engine bleed air valve acts as a pressure regulator and shutoff valve.

What do bleed trip sensors do on the Boeing 737-800?

• Illuminate the BLEED TRIP OFF light and close the respective engine bleed air valve automatically
• Illuminate the DUAL BLEED light and close the respective engine bleed air valve automatically
• Illuminate the BLEED TRIP OFF light and open the respective engine bleed air valve automatically
• Illuminate the WING BODY OVERHEAT light and close the respective engine bleed air valve automatically

Answer explanation

Bleed trip sensors illuminate the respective BLEED TRIP OFF light when engine bleed air temperature or pressure exceeds a predetermined limit, and the respective engine bleed air valve closes automatically.

What do duct pressure transmitters provide on the Boeing 737-800?

• Bleed air temperature indications
• Bleed air pressure indications
• Cabin pressurization status
• Engine performance data

Answer explanation

Duct pressure transmitters provide bleed air pressure indications to the respective (L and R) pointers on the bleed air duct pressure indicator.

What is the function of the isolation valve on the Boeing 737-800?

• To isolate the bleed air system from the hydraulic system
• To isolate the left and right sides of the bleed air duct
• To isolate the engine bleed air from the APU bleed air
• To isolate the bleed air system from the water system

Answer explanation

The isolation valve isolates the left and right sides of the bleed air duct during normal operations.

What is the purpose of the external air connection on the Boeing 737-800?

• To provide an alternate air source for engine start or air conditioning
• To provide an alternate air source for pressurizing the hydraulic system
• To provide an alternate air source for cooling the avionics
• To provide an alternate air source for cabin pressurization

Answer explanation

An external air cart/source provides an alternate air source for engine start or air conditioning.

What happens to the APU bleed air valve when the APU is shut down on the Boeing 737-800?

• It remains open
• It closes automatically
• It remains partially open
• It operates manually

Answer explanation

The APU bleed air valve closes automatically when the APU is shut down.

When does the DUAL BLEED light illuminate on the Boeing 737-800?

• Whenever the APU bleed air valve is open
• Whenever the engine bleed air valves are open
• Whenever the isolation valve is closed
• Whenever the APU bleed air valve is open and the engine bleed air switches and isolation valve are positioned to permit backpressure of the APU

Answer explanation

The DUAL BLEED light illuminates whenever the APU bleed air valve is open and the position of the engine bleed air switches and isolation valve would permit possible backpressure of the APU.