Question about startup procedure (no not the stop locks lol)

[tnorton776 0]

Simple Question. Why must the Avionics be turned off right before you start up the engine? Are you not allowed to start up with the avionics on and aligned?Tom Norton

[Turbine777 13]

I'm not sure, but I remember (partially remember) something in the military that was like that because the start up would cause damage or even fry the radios due to amperage. Doubt it is the same here, but am anxious to learn what it is.

[tnorton776 0]

I'm not sure, but I remember (partially remember) something in the military that was like that because the start up would cause damage or even fry the radios due to amperage. Doubt it is the same here, but am anxious to learn what it is.

Yes, my logical guess is that in the turboprop style plane it has something to do with the power/energy/amp from the start up sequence somehow damaging the avionics... awaiting an offical answer though. Do cessna Citations and small jets have the same issue? Or is it just turboprops

[downscc 1,327]

Yup, isolate the avionics bus from transient voltages when starting. Same in the Cessna 414 I fly, the master radio switch stays off until both engines are running and goes off before the mixture is pulled to cutoff. The big turbines are using air to start instead of a starter/generator used by the JS41, so the source for transient voltages is removed.