A320 Eng Fire Pb - Can it be undone?
 

Hey gang,

A friend of mine brought up this question the other day... If you "secure an engine" after engine failure by pressing the Engine Fire Pb but later decide to try re-lighting the engine instead, can you unpress the Engine Fire Pb and just have everything go back to normal? I suspect the IDG is donezo after that moment... but I don't know that for sure.

Thanks!

Yes. IDG remains mechanically connected.

Everything will go back to normal and the engine can be restarted, although You will need a very very very good reason to do that.

Totally agree.
I think the scenario here was; jumpy FO reached up and pushed the disconnect thinking there was engine damage by mistake.

Maybe there was a very very very bad reason that the button was pushed.

Is the hydraulic fluid shut off too on those engines with pumps as on Boeings? If so you will likely contaminate the hydraulic system coz the pump will have been running without proper cooling/lubrication due lack of fluid and will shed much metal.

Fire button pushed by mistake is not a good enough reason to undo it. Unless a failed engine was shut and wrong engine was secured. As long as you have one engine available its safer to just land back rather than try to undo it and realize that was another mistake.

Very hypothetical obviously:
Halfway between EWR and SJU. GEN 1 MELd, so APU running. APU fire followed by inadvertent ENG2 fire push button activation. Realize mistake, and push APU fire push button. Would you not try to undo ENG2 fire push button?

Tell me, how does that get pushed "inadvertently"? It's under a guard, and requires cross-cockpit verification.

When procedure for APU fire so poorly executed What's the guarantee that they won't push ENG1 Fire push button this time? With both engines shut you are more justified to undo both. My answer is to the original post where your scenario doesn't exist and I standby it.
Engines don't fail without reason and it failed was assessed damaged was secured. On what basis it can be reassessed to restart?

Although engines dont fail without reason, pilots sometimes close down the wrong engine. Now if only that Kegworth crew had realised their error....

You only "un-do" something in an Airbus if ECAM, QRH, Procedure, specifically calls for it.

I think maybe some of us are getting a little to wrapped around the axle over this haha. It was supposed to be a simple hypothetical to see if anyone knew if it "could" be done. I'm not saying anyone should. Not saying anyone should not. So we can all take a deep breath there :p

ECAM doesn’t cover any scenario. That’s why we’re there in the first place.

Well, you got me on the first part, obviously that pilot doesn't belong anywhere in an airplane. I will disagree with you on the second part. If the initial assessment and securing was done in haste, bells going off, later on after all is settled down, a full evaluation, followed by the restart could be a good choice.