Boeing 737NG - Hydraulics - SmartCockpit - Airline training guides, Aviation, Operations, Safety

STANDBY HYDRAULIC LOW PRESSURE Light - When illuminated amber:

It indicates output pressure of standby pump is low It is armed only when standby pump operation has been selected or automatic standby function is activated.

It indicates pressure of standby pump is below 20% It is armed only when automatic standby function is activated.

It indicates output pressure of standby pump is low It is armed only when standby pump operation has been selected.

It indicates pressure of standby pump is below 20% It is armed only when standby pump operation has been selected.

Correct! Wrong!

Standby Hydraulic System - The standby hydraulic system is provided as a backup if system A and/or B pressure is lost. The standby system can be only activated automatically.

True.

False.

Correct! Wrong!

The standby system can be activated manually or automatically.

The standby hydraulic system uses a single electric motor–driven pump to power:

Partial thrust reversers, rudder, leading edge flaps and slats (extend only), standby yaw damper.

Thrust reversers, rudder, leading edge flaps and slats (extend only), standby yaw damper.

Partial thrust reversers, standby rudder, leading edge flaps and slats (extend only), standby yaw damper.

Rudder, leading edge flaps and slats (extend only), yaw damper.

Correct! Wrong!

ALTERNATE FLAPS Master Switch - When placed in the ARM position, the ALTERNATE FLAPS Master switch:

It activates standby pump, and arms ALTERNATE FLAPS position switch.

It closes trailing edge flap bypass valve, activates standby pump, and arms ALTERNATE FLAPS position switch.

It arms ALTERNATE FLAPS position switch.

It closes Slats and trailing edge flap bypass valve, and arms ALTERNATE FLAPS position switch.

Correct! Wrong!

Hydraulic fluid used for cooling and lubrication of the pumps passes through a heat exchanger before returning to the reservoir. The heat exchanger for system A is located in main fuel tank No. 2 and for system B is in main fuel tank No. 1.

False.

True

Correct! Wrong!

The heat exchanger for system A is located in main fuel tank No. 1 and for system B is in main fuel tank No. 2.

Both A and B hydraulic systems have an engine–driven pump and an AC electric motor–driven pump. The system A engine–driven pump is powered by the No. 2 engine and the system B engine–driven pump is powered by the No. 1 engine.

False.

True.

Correct! Wrong!

The system A engine–driven pump is powered by the No. 1 engine and the system B engine–driven pump is powered by the No. 2 engine.

If the hydraulic system is not properly pressurized, foaming can occur at higher altitudes. Foaming can be recognized by:

Pressure fluctuations and the MASTER CAUTION and HYD annunciator lights illumination.

Pressure fluctuations.

Pressure fluctuations and the blinking of the related LOW PRESSURE lights. The MASTER CAUTION and HYD annunciator lights may also illuminate momentarily.

Pressure fluctuations and the illumination of the related LOW PRESSURE lights.

Correct! Wrong!

If one FLIGHT CONTROL switch is moved to STBY RUD:

It activates standby pump and opens standby rudder shutoff valve to pressurize standby rudder power control unit.

It deactivates the standby rudder power control unit.

It activates the standby rudder power control unit and deactivates the flight control shutoff valve isolating ailerons, elevators.

It activates the standby rudder power control unit.

Correct! Wrong!

In addition to hydraulic system A and B, the rudder can also be powered by the standby hydraulic system through the:

Standby Rudder PCU

System B Standby Rudder PCU.

System A Standby Rudder PCU.

Main Rudder PCU.

Correct! Wrong!

Variations in Hydraulic Quantity Indications - During normal operations, variations in hydraulic quantity indications occur when:

Raising or lowering the landing gear, extending leading edge devices, during severe icing.

The system becomes pressurized after engine start, raising or lowering the landing gear

Raising or lowering the landing gear, extending leading edge devices

The system becomes pressurized after engine start, raising or lowering the landing gear or leading edge devices, cold soaking occurs during long periods of cruise.

Correct! Wrong!

These variations have little effect on systems operation.

Minimum fuel for ground operation of electric motor-driven pumps is _____ in the related main tank.

600 kgs / 1300 lbs.

760 kgs / 1700 lbs.

420 kgs / 900 lbs.

500 kgs / 1100 lbs.

Correct! Wrong!

The ELEC 2 (system A) or ELEC 1 (system B) pump ON/OFF switch controls the related electric motor–driven pump. If an overheat is detected in either system, the related OVERHEAT light illuminates.

True.

False.

Correct! Wrong!

Standby Hydraulic System Leak - The LOW QUANTITY light illuminates when the standby reservoir:

Has a quantity of fluid less or equal to 20% of the maximum level.

Has a quantity of fluid less or equal to 10% of the maximum level.

Has a quantity of fluid less or equal to 30% of the maximum level.

Is approximately half empty.

Correct! Wrong!

Power Transfer Unit (PTU) - The purpose of the PTU is to supply the additional volume of hydraulic fluid needed to operate _____ when system B engine–driven hydraulic pump volume is lost.

The autoslats and leading edge flaps and slats at the normal rate

The slats and flaps

The leading edge flaps and landing gear

The slats and the landing gear

Correct! Wrong!

System A Hydraulic Leak - If a leak develops in the electric motor–driven pump or its related lines, or components common to both the engine and electric motor–driven pumps:

the quantity in the reservoir steadily decreases to zero.

The quantity in the reservoir steadily decreases to zero and all system pressure is lost.

The quantity in the reservoir steadily decreases to 20% and system pressure is minimum.

The quantity in the reservoir steadily decreases to 15% and all system pressure partially lost.

Correct! Wrong!

An engine–driven hydraulic pump supplies approximately _____ the fluid volume of the related electric motor–driven hydraulic pump.

3 times

4 times

6 times

10 times

Correct! Wrong!

System A Hydraulic Leak - If a leak develops in the engine–driven pump or its related lines, a standpipe in the reservoir prevents a total system fluid loss. With fluid level at the top of the standpipe, the reservoir quantity displayed indicates approximately _____

30% full.

50% full.

60% full.

20% full.

Correct! Wrong!

System A hydraulic pressure is maintained by the electric motor–driven pump.

The amber LOW pressure light for the No.1 Engine Driven Hydraulic Pump illuminates. What should you do?

Select STBY RUD ON.

Monitor hydraulic System A pressure.

Position the pump switch to OFF.

Start the ELEC pump

Correct! Wrong!

STBY RUD ON Light - When illuminated amber, it indicates the standby hydraulic system is commanded on to pressurize the standby rudder power control unit.

False.

True.

Correct! Wrong!

Power Transfer Unit (PTU) - The PTU uses system B pressure to power a hydraulic motor–driven pump, which pressurizes system A hydraulic fluid.

False.

True.

Correct! Wrong!

System B Hydraulic Leak - A leak in system B can significantly affect the operation of the standby hydraulic system.

False.

True.

Correct! Wrong!

A leak in system B does not affect the operation of the standby hydraulic system.

The RFF indication is displayed:

Valid only when airplane is on ground and when quantity is below 88% in either system A or B

Automatically when the hydraulic quantity is below 88% in either system A or B.

Only when hydraulic quantity is below 76% in either system A or B and the aircraft is on the ground with both engines shutdown or after landing with flaps up during taxi-in.

Valid only when airplane is on ground, with or without engines running and when quantity is below 76% in either system A or B

Correct! Wrong!

The hydraulic brake pressure indicator displays accumulator nitrogen pre-charge pressure of 1000 psi and:

Brake pressure from standby hydraulic system.

Brake pressure from hydraulic system B if it is greater than 1000 psi.

Brake pressure from hydraulic system A if it is greater than 1000 psi.

Brake pressure from the PTU.

Correct! Wrong!

Loss of an engine-driven hydraulic pump and a high demand on the system may result in an intermittent illumination of the LOW PRESSURE light for the remaining electric motor-driven hydraulic pump.

True.

False.

Correct! Wrong!

The flight control LOW PRESSURE light, Master Caution light, and the FLT CONT and HYD system annunciator lights also illuminate.

With the loss of hydraulic system B and with the system A operating normally:

Normal yaw damper functions are available as long as hydraulic system A is providing normal pressure and the yaw damper switch is ON.

Main yaw damper functions are available if the FLT CTL B switch is placed to STBY RUD and the yaw damper switch is reset to ON.

Main yaw damper functions are lost.

Main yaw daper functions are available as long as hydraulic system A is providing normal pressure and the yaw damper switch is ON.

Correct! Wrong!

Loss of an engine-driven hydraulic pump and a high demand on the system may result in an intermittent illumination of the LOW PRESSURE light for the remaining electric motor-driven hydraulic pump.

False.

True.

Correct! Wrong!

Landing Gear Transfer Unit - The system B engine–driven pump supplies the volume of hydraulic fluid needed to operate the landing gear transfer unit when all of the following conditions exist:

Airborne, No. 1 engine RPM drops below a limit value, landing gear lever is positioned UP, either main landing gear is not up and locked.

System B engine–driven pump hydraulic pressure drops below limits, airborne,

Airborne, No. 1 or No. 2 engine RPM drops below a limit value, landing gear lever is positioned UP or DOWN, either main landing gear is not up and locked.

Airborne, No. 1 or No. 2 engine RPM drops below a limit value, landing gear lever is positioned UP, either main landing gear is not up and locked.

Correct! Wrong!

STANDBY HYDRAULIC LOW QUANTITY Light - What is the true statement?

If Illuminated amber it indicates low quantity in standby hydraulic reservoir. It is only armed when on ground.

If Illuminated amber it indicates low quantity in standby hydraulic reservoir. It is only armed when in flight.

If Illuminated amber it indicates low quantity in standby hydraulic reservoir.

If Illuminated amber it indicates low quantity in standby hydraulic reservoir. It is always armed.

Correct! Wrong!

In case of loss of system A:

Nose wheel steering is not available.

Alternate nose wheel steering is not available.

Autoslats are not available.

Autopilot B is not available.

Correct! Wrong!

System A Hydraulic Leak - If a leak develops in the engine–driven pump or its related lines, a standpipe in the reservoir prevents a total system fluid loss. With fluid level at the top of the standpipe, the reservoir quantity displayed indicates approximately _____

50% full.

72% full.

40% full.

20% full.

Correct! Wrong!

System A hydraulic pressure is maintained by the electric motor–driven pump.

Standby Hydraulic System Leak - System B continues to operate normally, however, the system B reservoir fluid level indication decreases and stabilizes at:

Approximately 72% full.

Approximately 50% full.

Approximately 40% full.

Approximately 25% full.

Correct! Wrong!

Standby Hydraulic System Leak - If a leak occurs in the standby system, the standby reservoir quantity decreases to _____

Zero.

30%.

20%.

10%.

Correct! Wrong!

Electric Hydraulic Pump OVERHEAT Lights - What does this light indicate?

Hydraulic fluid used to cool and lubricate the corresponding electric motor driven pump has overheated or the pump itself has overheated.

Electric motor driven pump has overheated or loss of hydraulic fluid.

Electric motor driven pump has lost power and has therefore overheated

Electric motor driven pump has overheated

Correct! Wrong!

Boeing 737NG – Hydraulics

STANDBY HYDRAULIC LOW PRESSURE Light - When illuminated amber:

Standby Hydraulic System - The standby hydraulic system is provided as a backup if system A and/or B pressure is lost. The standby system can be only activated automatically.

The standby hydraulic system uses a single electric motor–driven pump to power:

ALTERNATE FLAPS Master Switch - When placed in the ARM position, the ALTERNATE FLAPS Master switch:

Hydraulic fluid used for cooling and lubrication of the pumps passes through a heat exchanger before returning to the reservoir. The heat exchanger for system A is located in main fuel tank No. 2 and for system B is in main fuel tank No. 1.

Both A and B hydraulic systems have an engine–driven pump and an AC electric motor–driven pump. The system A engine–driven pump is powered by the No. 2 engine and the system B engine–driven pump is powered by the No. 1 engine.

If the hydraulic system is not properly pressurized, foaming can occur at higher altitudes. Foaming can be recognized by:

If one FLIGHT CONTROL switch is moved to STBY RUD:

In addition to hydraulic system A and B, the rudder can also be powered by the standby hydraulic system through the:

Variations in Hydraulic Quantity Indications - During normal operations, variations in hydraulic quantity indications occur when:

Minimum fuel for ground operation of electric motor-driven pumps is _____ in the related main tank.

The ELEC 2 (system A) or ELEC 1 (system B) pump ON/OFF switch controls the related electric motor–driven pump. If an overheat is detected in either system, the related OVERHEAT light illuminates.

Standby Hydraulic System Leak - The LOW QUANTITY light illuminates when the standby reservoir:

Power Transfer Unit (PTU) - The purpose of the PTU is to supply the additional volume of hydraulic fluid needed to operate _____ when system B engine–driven hydraulic pump volume is lost.

System A Hydraulic Leak - If a leak develops in the electric motor–driven pump or its related lines, or components common to both the engine and electric motor–driven pumps:

An engine–driven hydraulic pump supplies approximately _____ the fluid volume of the related electric motor–driven hydraulic pump.

System A Hydraulic Leak - If a leak develops in the engine–driven pump or its related lines, a standpipe in the reservoir prevents a total system fluid loss. With fluid level at the top of the standpipe, the reservoir quantity displayed indicates approximately _____

The amber LOW pressure light for the No.1 Engine Driven Hydraulic Pump illuminates. What should you do?

STBY RUD ON Light - When illuminated amber, it indicates the standby hydraulic system is commanded on to pressurize the standby rudder power control unit.

Power Transfer Unit (PTU) - The PTU uses system B pressure to power a hydraulic motor–driven pump, which pressurizes system A hydraulic fluid.

System B Hydraulic Leak - A leak in system B can significantly affect the operation of the standby hydraulic system.

The RFF indication is displayed:

The hydraulic brake pressure indicator displays accumulator nitrogen pre-charge pressure of 1000 psi and:

Loss of an engine-driven hydraulic pump and a high demand on the system may result in an intermittent illumination of the LOW PRESSURE light for the remaining electric motor-driven hydraulic pump.

With the loss of hydraulic system B and with the system A operating normally:

Loss of an engine-driven hydraulic pump and a high demand on the system may result in an intermittent illumination of the LOW PRESSURE light for the remaining electric motor-driven hydraulic pump.

Landing Gear Transfer Unit - The system B engine–driven pump supplies the volume of hydraulic fluid needed to operate the landing gear transfer unit when all of the following conditions exist:

STANDBY HYDRAULIC LOW QUANTITY Light - What is the true statement?

In case of loss of system A:

System A Hydraulic Leak - If a leak develops in the engine–driven pump or its related lines, a standpipe in the reservoir prevents a total system fluid loss. With fluid level at the top of the standpipe, the reservoir quantity displayed indicates approximately _____

Standby Hydraulic System Leak - System B continues to operate normally, however, the system B reservoir fluid level indication decreases and stabilizes at:

Standby Hydraulic System Leak - If a leak occurs in the standby system, the standby reservoir quantity decreases to _____

Electric Hydraulic Pump OVERHEAT Lights - What does this light indicate?