Airframe Fire Protection Systems

Which fire-detection system measures temperature rise compared to a reference temperature?

Thermocouple.

Why does the Fenwal fire-detection system use spot detectors wired parallel between two separate circuits?

A short may exist in either circuit without causing a false fire warning.

The most common cause of false fire warnings in continuous-loop fire-detection systems is

dents, kinks, or crushed sensor sections.

A thermocouple in a fire-detection system causes the warning system to operate because

it generates a small current when heated.

The thermocouple fire-warning system is activated by a

rate-of-temperature rise.

The thermal switches of a bimetallic thermal-switch type fire-detection (single-loop) system are heat-sensitive units that complete circuits at a certain temperature. They are connected in

parallel with each other, but in series with the indicator lights.

When used in fire-detection systems having a single indicator light, thermal switches are wired in

parallel with each other and in series with the light.

In what areas of aircraft would the aviation mechanic find a carbon monoxide detector?

Cabin and flight deck.

. What occurs when a visual smoke detector is activated?

A lamp within the indicator illuminates automatically.

When air samples contain carbon monoxide, portable carbon monoxide detectors containing yellow silica gel will turn which color?

Green.

Smoke detection instruments are classified by their method of

detection.

Smoke detectors that use a measurement of light transmissibility in the air are called

photoelectrical devices.

A contaminated carbon monoxide portable test unit may be returned to service by

removing the indicating element and installing a new indicating element.

Smoke in the cargo and/or baggage compartment of an aircraft is commonly detected by which instrument?

Photoelectric cell.

Light refraction smoke detectors are activated when the detector

senses light reflected from smoke particles passing through a chamber.

The types of fire-extinguishing agents for aircraft interior fires are

water, carbon dioxide, dry chemical, and halogenated hydrocarbons.

Which fire-extinguishing agent is considered to be the least toxic?

Bromotrifluoromethane (Halon 1301).

A carbon dioxide (CO2) hand-held fire extinguisher may be used on an electrical fire if the

horn is nonmetallic.

The proper fire-extinguishing agent to use on an aircraft brake fire is

dry powder chemical.

What is the color code for fire extinguisher lines?

Brown.

Built-in aircraft fire-extinguishing systems are ordinarily charged with

halogenated hydrocarbons and nitrogen.

Regarding fire-extinguishing systems, which of the following statements is true?

Before connecting cartridge terminals to the electrical system, the system should be checked with a voltmeter to see that no voltage exists at the terminal connections.

What method is used to detect the thermal discharge of a built-in fire-extinguisher system?

A rupture of the red plastic disc in the thermal discharge line.

(Refer to Figure 21.) Using the chart, determine the temperature range for a fire-extinguishing agent storage container with a pressure of 330 psig. (Consider 330 psig for both minimum and maximum pressure.)

45 to 73°F.

(Refer to Figure 21.) Determine what pressure is acceptable for a fire extinguisher when the surrounding area temperature is 33°F. (Rounded to the nearest whole number.)

215 to 302 psig.

On a periodic check of fire extinguisher containers, the pressure was not between minimum and maximum limits. What procedure should be followed?

Replace the fire extinguisher container.

In some fire-extinguishing systems, evidence that the system has been intentionally discharged is indicated by the absence of a

yellow disc on the side of the fuselage.

A squib, as used in a fire-protection system, is a

device for causing the fire-extinguishing agent to be released.

A fire extinguisher container can be checked to determine its charge by

weighing the container and its contents.

If a fire extinguisher cartridge is removed from a discharge valve, it should be

used only on the original discharge valve assembly.

Which of the following are fire precautions which must be observed when working on an oxygen system?

Display "No Smoking" placards, provide adequate fire-fighting equipment, keep all tools and oxygen servicing equipment free from oil or grease, and avoid checking aircraft radio or electrical systems.

Maintenance of fire-detection systems includes the

replacement of damaged sensing elements.