In case of a hung start or a high T4 you retard the FFCL all the way back and release the start button.Keeping that button pressed will continue to provide an ignition spark.There is another switch on the center console marked "crank". That is to be used if you just want to motor the engine without the ignition spark.That allows the excess fuel to be ejected and may reduce the high T4.
There is no arming the ignition system.Once the battery is on the button is "hot". The engine will start turning if the button is engaged at that point.
The only other interlock is a mechanical one.If the rotor brake is fully up and aft and in the slot (i.e engaged) there is a mechanical stop that prevents the FFCL from being moved forward.This prevents the rotors being turned and accelerated with the rotor brake "on".
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