Powerplant - Engine Fire Protection

Question 1

When using a thermocouple type fire detector system, what happens if the engine overheats slowly?

Answer 1

A thermocouple depends on the rate of temperature rise and will not give a warning if the engine slowly overheats or a short circuit develops

Question 2

What is the most common cause of a false fire warning in a continuous loop detector system?

Answer 2

Dents, kinks, or crushed sensing elements

Question 3

What two methods are used to distribute fire extinguishing agents?

Answer 3

Mechanical and electrical

Question 4

What method is used to determine proper fire extinguisher container pressure?

Answer 4

The container pressure gauge

Question 5

What method other than a pressure gauges used to indicate low agent pressure in a container?

Answer 5

Some aircraft are equipped with a low pressure warning light in the cockpit

Question 6

What is the purpose of the yellow and red discharge plugs in a turbine engine fire extinguishing system?

Answer 6

The yellow plug indicates normal discharge and the red plug indicates thermal discharge

Question 7

What are two methods commonly used to distribute the fire extinguishing agent to the engine?

Answer 7

Many systems use perforated tubing or discharge nozzles to discharge the agent

Question 8

How does the fire extinguishing agent put out the fire?

Answer 8

It dilutes the atmosphere so it wont support combustion

Question 9

What is an HRD Fire extinguishing system?

Answer 9

High rate of discharge

Question 10

How is the fire extinguishing agent distributed from an HRD system?

Answer 10

It is delivered from open ended tubes

Question 11

How long does it take to discharge the extinguishing agent in an HRD system?

Answer 11

1 to 2 seconds

Question 12

Which type of fire detection system gives a more complete coverage of a fire hazard?

Answer 12

A continuous loop detector system

Question 13

What are the main categories of engine fire protection systems?

Answer 13

Spot detection, continuous loop, and flame detectors

Question 14

Name examples of spot detection type systems.

Answer 14

Thermal switch and thermocouples

Question 15

Name examples of continuous loop detection systems.

Answer 15

Fenwal (one wire), Kidde (two wires) and pneumatic

Question 16

How many thermocouples are required for engine fire detection?

Answer 16

The number of thermocouples used in an engine fire detection depend on the size of the fire zone and the total circuit resistance.

Question 17

Where does a thermocouple fire detector system get its electrical power from?

Answer 17

The thermocouple produces power to close a relay, and power from the aircraft electrical system flows through the relay to the warning light.

Question 18

Describe a thermal switch fire detector system?

Answer 18

Thermal switch systems have one or more lights that are energized by the aircrafts electrical system when a heat sensitive thermal switch closes the circuit at a specific temperature.

Question 19

How are thermal switches electrically connected in the circuit?

Answer 19

The thermal switches are connected in parallel with each other but in series with the warning light. A temperature rise in any one section of the circuit will cause a thermal switch to close and complete the circuit to indicate a fire or overheat condition.

Question 20

What is the color marking used to identify fire extinguishing lines?

Answer 20

A brown tag with a row of black diamonds