Originally Posted by
nnc0
It's going back a ways but I recall the DHC dash 8 (PW 120's turboprops) had an ETOPS AFM supplement for some south pacific/ aus/nz operators.
I doubt a piston engine would ever be ETOPS qualified.
What about wankel engines?
And how many piston engines are needed for long haul? Is 4+ needed (B-36 has 6, Hughes Hercules has 8, Saunders-Roe Princess has 10 and Dornier X has 12), or is 3 enough?