Can one reset an engine fire switch?
 

Have asked this question to several fellow 767 pilots with varying responses...

When the engine fire switch is pulled the fuel valves close, engine bleed valves close, the generator drive is disconnected, engine hydraulic pump is shutdown and the fire extinguisher bottles are armed....

If the engine fire switch was then returned to the down position will the above actions (other than generator drive disconnect) be reversed allowing an engine re-start???


Cheers.....

Yes

Yes

You should also get your Generator back, since the fire handle does not disconnect the IDG. It trips the field and the GCB.

If the engine were to windmill with the fire handle pulled for a prolonged period of time, it would trash the hydraulic pump.

N2

disconnect gen drive??
should be (trips associated gen field and gen breaker)
gen field would have to be reset, me thinks

As I understand it, the fire switch
1/ shuts off fuel
2/ disables ignition
3/ trips gen field
4/ shuts off hyd pump supply
5/ closes air con air bleed
6/ arms fire extinguisher

This means that the CSD/IDG is still connected and the hyd pump has no cooling/lubrication fluid flow.

It is possible to reset the switch I think, but you'd need a real good reason because the hyd pump would almost certainly contaminate the hyd system with metal.

Our (B757/767) SOPs call for any engine failure on take-off and prior to flap retract to be treated as an Engine Fire/Severe Damage/Separation case and the appropriate recall actions to be carried out. If following the recall actions, which include the pulling of the Fire Switch but only firing the bottle/s if there is a fire, an attempted relight is required, then the fire handle is restowed. As long as the handle has not been pulled for longer than approx. 5 minutes, all services will be restored. Longer than approx. 5 minutes and the appropriate engine driven hyd pump is automatically locked out to prevent damage. Therefore following a successful inflight start after that time, the appropriate engine driven hyd pump would not be available irrespective of pump switch position.

[This message has been edited by Expert (edited 04 December 2000).]