7. Engine and APU

What type of engines power the Boeing 737?

• CFM56–7
• CF6–80C2
• PW4000
• Trent 800
• None

Answer explanation

The Boeing 737 is powered by two CFM56–7 engines.

What components make up the N1 rotor in the CFM56–7 engines?

• Fan, high-pressure compressor, and high-pressure turbine
• Fan, low–pressure compressor, and low–pressure turbine
• Fan and high-pressure turbine
• Low-pressure turbine and high-pressure turbine
• None

Answer explanation

The N1 rotor consists of a fan, a low–pressure compressor, and a low–pressure turbine.

Which rotor drives the engine gearboxes in the CFM56–7 engines?

• N1 rotor
• N2 rotor
• Both N1 and N2 rotors
• Neither rotor
• None

Answer explanation

The N2 rotor drives the engine gearboxes.

What does the dual–channel electronic engine control (EEC) regulate?

• Fuel flow
• Engine temperature
• Each engine
• Cabin pressure
• None

Answer explanation

The dual–channel electronic engine control (EEC) regulates each engine.

How is thrust set on the Boeing 737 engines?

• Automatically by the autopilot
• Automatically by the autothrottle system or manually by the flight crew
• Manually by the ground crew
• Automatically by the flight management system
• None

Answer explanation

Thrust is set by the autothrottle system or manually by the flight crew.

Where are the primary engine indications normally displayed?

• Captain’s inboard DU
• First Officer’s inboard DU
• Center forward panel upper DU
• Lower display unit (DU)
• None

Answer explanation

The primary engine indications are normally displayed on the center forward panel upper DU.

What conditions automatically display the secondary engine indications?

• When the engines are started
• When the displays initially receive electrical power, in flight when an engine start lever is moved to CUTOFF, in flight when an engine N2 RPM is below idle, and when a secondary engine parameter is exceeded
• When the airplane is on the ground
• When the autopilot is engaged
• None

Answer explanation

The secondary engine indications are automatically displayed under the specified conditions.

How are oil pressure, oil temperature, and engine vibration indications displayed?

• Digital readouts only
• Vertical indication/moving pointers only
• Both digital readouts and vertical indication/moving pointers
• Digital readouts and horizontal pointers
• None

Answer explanation

Oil pressure, oil temperature, and engine vibration indications are displayed as both digital readouts and vertical indication/moving pointers.

What color do the digital readout, box, pointer, and indicator change to if N1, EGT, or N2 exceed their limits?

• Blue
• Green
• Red or amber
• White
• None

Answer explanation

If N1, EGT, or N2 exceed their limits, the digital readout, box, pointer, and indicator change color to red or amber.

When is the EEC powered during a battery start with no power on the airplane?

• Immediately when the start switch is turned on
• When the engine accelerates to a speed greater than 15% N2
• When the battery switch is turned on
• When the APU is started
• None

Answer explanation

The EEC is powered when the engine accelerates to a speed greater than 15% N2 during a battery start with no power on the airplane.