PT6 Starting question
So all the helicopters I have flown with the exception of the S61 do not have a separate igniter switch, meaning the starter button did both the starter and the igniters simultaneously. My Nephew is just getting into a turbine with an AirTractor for crop spraying and it has a PT6. This FW has a separate ignitor switch and the procedure in the manual is to activate the starter and at 10-12% activate the ignitor switch just prior to inducing fuel. Why would this be different for basically the same engine as a 212/412/Aw139? Seems like an unnecessary step to me.
Any P&W reps out there that can explain the reason for that?