Aircraft Master Warning and Annunciator Systems

Question 1

The purpose of the master warning and annunciator system is to _______.

Answer 1

The purpose of the master warning and annunciator system is to alert and inform the pilot of the aircraft’s condition.

Question 2

Each individual operational system of the aircraft has a fault indicator light located on the ______.

In contrast, the master warning and annunciator system lights are located on the ______ easy visibility.

Answer 2

Each individual operational system of the aircraft has a fault indicator light located on the overhead panel or fire module.

In contrast, the master warning and annunciator system lights are located on the forward panel in front of the pilot and copilot for easy visibility.

Question 3

When an operational system malfunctions, that system’s fault indicator illuminates on the _______. Additionally, the appropriate Master Caution, Fire Warn, and annunciator lights illuminate directly in the pilot’s field of vision.

Answer 3

When an operational system malfunctions, that system’s fault indicator illuminates on the overhead panel. Additionally, the appropriate Master Caution, Fire Warn, and annunciator lights illuminate directly in the pilot’s field of vision.

Question 4

Illumination of the Master Caution or Fire Warn annunciators alert the pilot and copilot to do what?

Answer 4

Illumination of the Master Caution or Fire Warn annunciators alert the pilot and copilot to check the system fault indicators on the overhead panel.

Question 5

Each aircraft manufacturer and type of aircraft may use a different design and layout for the indicator system, but the purpose remains the same: to ________.

Answer 5

Each aircraft manufacturer and type of aircraft may use a different design and layout for the indicator system, but the purpose remains the same: to inform the pilots of system malfunctions and status.

Question 6

Two Master Caution lights are located_______ quick recognition of an alarm indicator that has been set due to a faulty system.

Answer 6

Two Master Caution lights are located in direct view of the pilot and copilot for quick recognition of an alarm indicator that has been set due to a faulty system.

Question 7

After recognizing a fault, either the pilot or the copilot can extinguish both indicators by_______

Answer 7

After recognizing a fault, either the pilot or the copilot can extinguish both indicators by pressing the Master Caution light on the forward panel in view.

These annunciator panels are designed as general system indicators. This means the pilot or copilot will look at another system panel associated with the illuminated annunciator to isolate a problem.

Question 8

What lights are red in color and alert the crew of a dangerous malfunction requiring immediate action?

Advisory

Warning

Indicator

Answer 8

Warning

Question 9

What is used to alert the pilot of an emergency condition so corrective action may be taken?

Master Caution light

System Indicator light

Answer 9

Master Caution light

Question 10

The annunciator uses several types of electrical switches and relays to indicate a fault.

Name four common types.

Answer 10

Micro Switch

Relays

Thermal Switch

Pressure Switch

Question 11

_______ are used to indicate a position of a system component, such as a door or landing gear.

Answer 11

Micro switches are used to indicate a position of a system component, such as a door or landing gear.

Question 12

_________ are used for electrical flow indications, such as the loss of generators. They are also used with other switches to aid in the resetting of the annunciator circuit.

Answer 12

Relays

Question 13

________ are used to activate the circuit when a specific temperature is reached in a system or component. It may be used for the compartment heater temperature circuit. If the temperature is too high, the annunciator is lit.

Answer 13

Thermal switches are used to activate the circuit when a specific temperature is reached in a system or component. A thermal switch may be used for the compartment heater temperature circuit. If the temperature is too high, the annunciator is lit.

Question 14

_______ are used to activate the annunciator when a system’s pressure is not within normal operating parameters. The aircraft hydraulic system uses this type of switch.

Answer 14

Pressure switches are used to activate the annunciator when a system’s pressure is not within normal operating parameters. The aircraft hydraulic system uses this type of switch.

Question 15

What color of warning light is used to indicate an abnormal condition considered to be nonhazardous?

Red
Blue
Yellow
Green

Answer 15

Yellow

Question 16

To identify the exact fault with the aircraft, the pilot would investigate which indicator panel?

Individual System indicator
Master Caution and Warning indicator
Master Caution and Warning System indicator
All of the above

Answer 16

Individual System indicator

Question 17

What type of switch would be used to monitor the electrical flow from a generator?

Relay
Thermal switch
Micro switch
Pressure switch

Answer 17

Relay

Question 18

What happens when the Master Warning light is momentarily pressed?

LEDs blink and silence the buzzer.
The alarm circuit is reset for further monitoring.
The individual local indication is reset.
Only the buzzer is silenced.

Answer 18

The alarm circuit is reset for further monitoring.

Question 19

What colors are used for normal indication and operation?

Green
Blue
White
All of the above

Answer 19

All of the above

Question 20

What type of switch would be used to monitor the engine compartment temperature?

Relay
Thermal switch
Micro switch
Pressure switch

Answer 20

Thermal switch

Question 21

What is the result of a loss of electrical power to the Master Caution and Warning SCRs?

LEDs blink and silence the buzzer.
The alarm circuit is reset.
The individual local indication is reset.
Only the buzzer is silenced.

Answer 21

The alarm circuit is reset.

Question 22

What is the probable cause for the Master Caution LEDs to remain illuminated while there are no alarming conditions indicated by the individual systems?

Reset switches failed.
SCR failed in the triggered position.
Generator Failure transistor is triggering the SCR.
Door Open LED should be illuminated.

Answer 22

SCR failed in the triggered position.

Question 23

When does the buzzer NOT activate during an alarming condition?

Dangerous Condition (RED)
Non Dangerous Abnormal Condition (YELLOW)
Normal Operation (GREEN, WHITE, or BLUE)

Answer 23

Non Dangerous Abnormal Condition (YELLOW)

Question 24

What component will shift line up to ground when a 0.6 to 0.75 voltage differential is measured between the system and indication side of the circuit?

SCRs
Diodes
LEDs
Transistors

Answer 24

Transistors