Great thread, need to get it going again.
In the Flight Manuals I have come across, I have never seen a specified time peroid before you use the second fire extinguisher bottle.
I tried to get an answer from Sikorsky once about getting a recommendation for the system that is in the S76, but they declined.
The emergency checklist in the S76 says "If fire persists - use reserve bottle".
What is that 10 sec? 30 sec? long seconds anyway.
It varies depending on many factors I'll guess, type of detector, size of engine bay, manufacturer????
Anybody have a suggestion, or experience I'd be glad.