It's a long time ago but I can't remember in 6 years of operating 4 Aircraft flying @ 1000 hrs (250 ish apiece) a year there ever being an inverter problem. But you have got my mind working overtime. Before you started the 2nd engine, if the battery power (DC) was a bit low we used to advance the power Lever to 70% N1 and switch the respective generator on until the load fell below 115A (1min) we would switch the gen back off and then start the second engine. Once both engines stabilised, N1 60-64? Advance both power levers to 70%N1, then turn on both generators. So you can see that the ALTs were working really hard and the tiny quill drives I guess did take a hammering. What I can tell you was the quill drives were tiny in fact everything was - the compressor section of each engine was the size of a can of baked beans turned on its side and it had quite a few stages (4/5) of compressor but the Allisons were really good, powerful little engines.
I seem to remember if you got an AC INVERTER caption you reset the CBs first (if popped) if that didn't clear it you moved the Alt switch to SPARE if that didn't work you lost loads of stuff including the ASE.
Now I need to lie down.
Last edited by MOSTAFA; 15th Jun 2016 at 08:25.