A319/320 Engine Fire Test

[Hunter1982]

I don't have a MEL/MMEL to check this, but could you start a flight if while performing the engine fire test, say engine 1, one of the squib lights does not illuminate? After checking the lights, you confirm the squib light is operative.

Cheers,

[Nick 1]

m) One may be inoperative on each engine provided that the associated bottle pressure is checked before the first flight of each day

m) Both may be inoperative on one engine for four flights or 15 flight hours, whichever occurs first, provided that the associated bottles pressures are checked before each flight.

Nick 1

[Hunter1982]

Thanks for your reply Nick. I think here you are referring
to the light itself. In this very case, the light is ok but the squib light doesn't turn on when pressing the fire test button. So, could this mean the bottle won't fire up the agent if needed, i.e. one bottle
is inop.

If this were the case, could you start the flight as per MEL??

Cheers,

[Beeline]

There is an Mel ref with a maintenance action to check the continuity of the firing circuit. In the situation you discribe the test low voltage circuit is prob u/s.

[i_like_tea]

If it doesn't light up, there yes, it may not be functioning.

We had a a/c come back from maintenance a little while ago and on the right engine, both squib lights didn't work during the test.
Turns out something hadn't been reconnected..

[Beeline]

I'll expand on my statement with consideration to the first post. On a squib test you are passing a low test voltage through the squib. this is a continuity check that won't blow the bottle.

The firing circuit is 28v that is enough to fire the squib.

If during your fire test the light does not illuminate an Engineer must confirm it is the test circuit. We basically take the plug off and simulate the bottle being fired under 28v conditions and check the squib with a low voltage tester. If that is the case it can be dispatched under the test being faulty and not the squib.

[Swedish Steve]

m) One may be inoperative on each engine provided that the associated bottle pressure is checked before the first flight of each day
You are quoting MEL for bottle discharged light, not squib lights.

But just ask how you check the bottle pressure? There is no gauge on the bottle so it is quite time consuming.