FSS System

Question 1

Fire detection is provided by what type of sensors are in the N2 protected areas?

Answer 1

Thermal

Question 2

What type of sensors are in the FE 1301 protected areas?

Answer 2

Optical for A models (also in B models, but detection only no protection)

Question 3

The automatic nitrogen discharge function is activated when any one of the four Engine Start switches is in _____ or _____ and the CPU receives signals from the engine nitrogen FSS automatic discharge relays.

Answer 3

Run; start

Question 4

Where does N2 discharge? What is the N2 capacity & storage arrangements?

Answer 4

Discharges in unmanned areas only; capacity of 750 lbs per dewar; 2 dewars per airplane

Question 5

How many nitrogen dewars are on the C-5M?

Answer 5

2 (located in the wing roots aft of the rear wing beam)

Question 6

Each dewar has a capacity of?

Answer 6

750 lbs

Question 7

What is the minimum nitrogen allowed for use for firefighting capability?

Answer 7

250 lbs

Question 8

Is nitrogen required to be onboard for flight?

Answer 8

No

Question 9

How many total FSS zones are there?

Answer 9

Twelve

Question 10

Which zones have automatic nitrogen discharge capability?

Answer 10

 Left Outboard Wing (Zone 1)
 Left Inboard Wing (Zone 2)
 Right Inboard Wing (Zone 3)
 Right Outboard Wing (Zone 4)

Question 11

When are the automatic zones armed for capable discharge?

Answer 11

The automatic discharge function is armed through the engine nitrogen FSS automatic discharge relays when an Engine Start switch is placed in the RUN or START position.

Question 12

Can you manually discharge nitrogen into zone 5 while it is being automatically discharged into zone 4?

Answer 12

Yes

Question 13

If more than one zone detects a fire, what is the priority system of zones 5-12?

Answer 13

There is a priority system for zone 5-12 alarm pushbuttons. Depressing any of these pushbuttons to the right or below a pushbutton that was previously depressed will cancel out the previous signal

Question 14

What indications do you have when a fire has been detected?

Answer 14

FSS FIRE Warning displayed on the MFDU, a MASTER CAUTION annunciation, and an audible alert

Question 15

In zones 1-4, what will happen if a second auto discharge starts while the first one is still discharging?

Answer 15

The second automatic zone will discharge N2 for the remaining time of the first zones 45 second time period. At the conclusion of that cycle, the second zone will then start up it’s own auto 45 second cycle.

Question 16

Can you simultaneously discharge in zones 1 through 4? What about zones 1 through 4 AND one zone within 5 through 12?

Answer 16

Yes; Yes

Question 17

Describe the priority system of the zone alarm pushbuttons?

Answer 17

 Zones 1 – 4 are not part of the priority system  when a fire is sensed in any of these zones an auto-discharge occurs
 Zones 5 – 12 right and down has higher priority, but 5-12 have no priority effect on zones 1 – 4
 Simultaneous discharge can occur in zones 1 thru 4 as well as 1 thru 4 and one zone in the 5 – 12 range
 In zones 5 thru 12, N2 must be manually discharged and will only occur in a single zone in the 5 – 12 range

Question 18

Does the battery need to be on to discharge N2 from the nosewheel well FSS panel? Why?

Answer 18

No; It is hot-wired to the hot battery bus when the FSS arming switch in the nosewheel well is in the POWER/ARM position

Question 19

What is the elapsed discharge time from the Engineer’s FSS panel? Nosewheel FSS panel?

Answer 19

45 seconds; continuous

Question 20

If a zone discharge in zones 5 - 12 has been started manually and subsequently a zone alarm light goes on in one of the zones 1 through 4, how long will it discharge?

Answer 20

Zones 1 - 4 will auto-discharge and continue for remainder of initial timer started by zones 5-12; it must subsequently be discharged manually for further operation

Question 21

What if you accidentally hit a wrong, higher priority FSS button?

Answer 21

Place arming switch to PANEL SAFE then to ARM, then press correct button

Question 22

Which zone button located on the nosewheel well FSS panel in not operable?

Answer 22

Cargo/Center Wing Avionics

Question 23

What areas are protected by the pushbuttons on the nosewheel well FSS panel?

Answer 23

Left wing, right wing, underfloor forward, underfloor aft

Question 24

How much can the N2 leak and the system still be considered “good”?

Answer 24

50 pounds per DEWAR in 12 hours; allow 1 hour after servicing for stabilization

Question 25

You are departing on a mission from Dover AFB, how much N2 should you have?

Answer 25

650 lbs / DEWAR minimum