Fire Protection

Question 1

Q.3.1. What fire detection/protection do the cargo compartments have?

Answer 1

• The forward and aft cargo compartments each have smoke detectors in a dual loop configuration. Normally, both detection loops must sense smoke to cause an alert.

• ETOPS aircraft have a total fire suppression time of 195 minutes. This includes 180 minutes to land at an airport plus an additional 15 minutes.

• Non-ETOPS aircraft provide for a 60-minute diversion and a 15-minute reserve totaling 75 minutes of fire suppression.

Reference: FRM B737NG/MAX 8.2.5.1 and 8.2.5.3

Question 2

Q.3.2. Within how many minutes must you land after initial discharge of the cargo bay fire suppression system?

Answer 2

60 Minutes
(MAX8E/ -800E) – 180 Minutes

Note: E indicates ETOPS equipped aircraft.

Reference: AOM 3.15.1

Question 3

Q.3.3. During a Cargo Fire Test, the Detector Fault light will illuminate under what condition?

Answer 3

If one or more detectors in the loop has failed.

Reference: FRM B737NG/MAX 8.2.8.1

Question 4

Q.3.4. What indications will you receive during a successful Cargo Fire test?

Answer 4

Fire Warning bell sounds
• Both Master FIRE WARN lights will illuminate
• Extinguisher lights will illuminate
• FWD and AFT cargo fire illuminate when all detectors in selected loops respond to the fire test
• Cargo fire bottle DISCH light illuminates

(opens in a new tab)Reference: AOM 16.8.2

Question 5

Q.3.5. During cruise, the Cargo Fire (FWD/ AFT) Warning light illuminates Red, Master Fire Warn lights illuminate and the fire warning bell sounds. What condition exists?

Answer 5

• At least one detector in each loop detects smoke
• With power failed in one loop, at least one detector on the remaining loop detects smoke

(opens in a new tab)(opens in a new tab)Reference: FRM B737NG/MAX 8.1.5(opens in a new tab)

Question 6

Q.3.6. With a cargo fire, what indications would you expect to see after discharging the bottle?

Answer 6

After the initial indication of a cargo compartment fire and discharging the bottle, the FWD/AFT cargo fire warning light(s) can extinguish, remain illuminated, or re-illuminate over the remainder of the flight.

(opens in a new tab)Reference: FRM 8.2.5.2

Question 7

Q.3.7. On the ground during engine start and after the pushback Crew has been cleared off, they give you hand signals for an Engine Fire with no fire indications on the flight deck. What may be the actual condition?

Answer 7

You may have an Engine Tailpipe Fire.

Reference: QRH NG/MAX 8.1.4, AOM 5.7, FOM 18.4

Question 8

Q.3.8. What occurs if one of the two engine fire detection loops fail with the OVHT DET switch in NORMAL?

Answer 8

If one loop fails with the OVHT DET switch in NORMAL, that loop is automatically deselected and the remaining loop functions as a single loop detector. There is no flight deck indication of single loop failure.

Reference: FRM B737NG/MAX 8.2.2.1

Question 9

Q.3.9. What powers the engine overheat and fire detection? Extinguishing?

Answer 9

• Engine overheat and fire detection powered by the battery bus.
• Engine fire extinguishing powered by the hot battery bus.

Reference: FRM B737NG/MAX 8.2.2

Question 10

Q.3.10. When selecting OVHT/FIRE during the Fire/Overheat Warning Test, you notice the FAULT Light is illuminated. What may be the problem and how do you determine in which engine the fault occurred?

Answer 10

If the FAULT light illuminates, a detection loop is inoperative. The related ENGINE FIRE WARNING switch and ENG OVERHEAT light do not illuminate. To determine the inoperative loop follow the procedure “To Determine the Specific Inoperative Loop” in AOM 16.8.1.

Reference: AOM 16.8.1

Question 11

Q.3.11. During a Cargo Fire Detection System Test, how can you determine if a loop is inoperative?

Answer 11

If a cargo fire warning light does not illuminate and the DETECTOR FAULT light does illuminate, a detection loop is inoperative.

Reference: AOM 16.8.2

Question 12

Q.3.12. What consideration, with regards to the landing gear, should be taken during execution of the Wheel Well Fire checklist in QRH NNC 8 Fire Protection following a wheel well fire warning?

Answer 12

Landing gear speed limitations should be observed during this checklist.

Reference: AOM 5.6.1, QRH NG 8.18/QRH MAX 8.2

Question 13

Q.3.13. In an ETOPS aircraft with an ARMED Cargo Fire switch what occurs when pushing the Cargo Fire Discharge switch?

Answer 13

The first extinguisher bottle discharges into the selected compartment and the timer set to discharge the second extinguisher bottle with a reduced metered flow.

Reference: MAX FRM 8.1.5, 8.2.5.3/NG FRM 8.1.4, 8.2.5.3