Is there any case in which the fire handle should be pulled without a fire indication?
It was standard practice on the GF Tristar, that with an u/s APU you shut down Nbr 3 engine last by pulling the fire handle. The engineer then checked that the HPSOV was closed and reset the fire handle. The engine would run for over a minute before shutting down. The thinking was that when shutting down engines you needed a pneumatic source (APU) to motor the engine over if there was a tailpipe fire. With the APU Inop then shutting the spar valve meant there was no fuel in the engine to cause a fire.