Brushless elctric engine on battery one story. Piston engine -> generator -> same electric engine, another
Speaking form development experience, of one aux PBS turboshaft running air compressor and AC genset.
Our luck, helicopter was big enough to sustain all extra weight penalty....
@500e
let's hope that some of PBS new turboshaft design can sustain (prohibitive) certification expenses. Mi SAFIR APUs from the same company are certified.
@onetrack
yes, but please read in which stages of flight and if we goes on Maryland side, than this can be useful reading too ->
http://drum.lib.umd.edu/bitstream/19...i-umd-5771.pdf