For you Robo flyers out there......
Heliair has a neat idea..
One switch does it all (Well almost all) Start up as normal then "Flick" the avionics switch and all the other stuff comes alive - Transponder, Giro's, Radio's, CD player. Makes for an easy start.
It's also very cheap to fit (And no I don't work for Heliair Heliport !)