Fire Protection

Question 1

How many fire and overheat detection systems are installed on the CRJ-700?

Answer 1

Three.
APU compartment.
Engine nacelles.
Main landing gear.

Question 2

How many smoke detection systems are installed?

Answer 2

Three.
Forward and aft cargo.
Lavatory.

Question 3

Where are is fire suppression equipment located?

Answer 3

APU.
Engine nacelles.
Forward and aft cargo compartments.

Question 4

How many fire/overheat detection loops does each engine have?

Answer 4

Two.

A and B.

Question 5

How are the loops constructed?

Answer 5

Within a tube, two wires are separated by an insulator. One wire carries charge, the other is grounded. When the tube heats up, the insulator resistance falls and the current from the live wire is transferred to the grounded wire.

Question 6

What warnings are presented to the flight crew in the event of an engine fire?

Answer 6

A red L or R engine fire EICAS warning with an associated bell, the associated fire push switch and both master caution lights.

Question 7

What does an amber L or R FIRE FAIL EICAS message mean?

Answer 7

Both fire loops have failed on the associated engine side.

Question 8

How many engine fire bottles are there?

Answer 8

Two.

Question 9

What happens when the fire push switch is pressed?

Answer 9

The associated engines hydraulic, fuel and bleed air shut off valves will close, the AC generator will trip off line and the engine ignition is turned off.

Question 10

How does the APU fire detection and suppression modes operate?

Answer 10

Ground mode - a sensed fire/overheat automatically shuts the APU off and discharges the fire bottle 5 seconds after a fire is detected.
Flight mode - a sensed fire/overheat will automatically shutdown, however the fire bottle must be manually discharged.

Question 11

How many APU fire bottle are there?

Answer 11

One.

Question 12

What does pushing the APU fire switch light do?

Answer 12

Closes the APU fuel shutoff valve.

The shutdown also trips the generator and the APU load control valve closes.

Question 13

How many smoke detectors are installed in the cargo bays?

Answer 13

Two in the aft, three in the forward.

Question 14

What happens when the aft cargo compartment smoke detectors detect a fire?

Answer 14

The cargo bay shutoff and exhaust valves close to contain the smoke. The heater is also shutdown.

Question 15

How many fire bottle are installed in the cargo section?

Answer 15

Two. Connected to both forward and aft cargo compartments.

Question 16

What happens when the aft cargo compartment fire push switch light is pressed?

Answer 16

The squibs on the cargo fire bottles are armed.
The green push to discharge switch illuminates.
The aft cargo ventilation valves closes and the heater is turned off.

Question 17

How are the cargo fire bottles rigged to discharge?

Answer 17

One is high rate that discharges immediately, the other is a slow rate which discharges over 60 minutes.

Question 18

How is the lavatory fire suppression system rigged?

Answer 18

A heat sensitive fire bottle in the waste bin will discharge once a certain temperature is exceeded.

Question 19

How is the fire protection system tested?

Answer 19

7 red and 5 green lights.

Question 20

Can the APU fire bottle be discharged without power on the aircraft?

Answer 20

Yes.

Question 21

Can the APU fire detection system detect a fire without power on the aircraft?

Answer 21

No.