TAP013: A320 Engine and APU Fire Protections

Aircraft Fire Protection Systems for the Engines and APU provide Fire and overheat detection and extinguishing systems (as opposed to just fire or smoke detection like in other systems).
The engines and the APU each have their own fire and overheat detection systems. These consist of:
Two identical fire detection loops (A and B) which are mounted in parallel and a Fire Detection Unit or FDU.
The fire detection loops have three sensing elements for each engine. They are found in the pylon nacelle, in the engine core and in the engine fan section
There is one sensing element in the APU compartment.

The Fire detection unit processes all the warnings and cautions originating in the sensing elements.
There are 4 things that will cause a fire warning to appear:
- a fire signal from both loop A and B,
- a fire signal from one loop when the other is faulty,
- a break in both loops occuring within 5 s of each other (flame effect), or
- a test performed using the control panel.
We get a loop-fault caution if :
- one loop is faulty,
- both loops are faulty or,
the fire detection unit fails.

Scenario of the week

Imagine that as you taxi out you get the engine fire warning. Run through the ECAM we've just read out and then think about all the different things you need to consider. You've got ATC, Fire crews, cabin crew, passengers, the company and of course each other to sort out. How will you prioritise them all and what can you ask each group to help you make your decision?