I was astonished recently to learn that a light twin loses something like 80% of its performance with a single engine failure. But I was even more surprised to learn that there is apparently no published POH engine out allowance for the Seneca even at sea level and ISA. Is that really true? If so, I wouldn't go near one with a barge pole.
Why is there no twin PT6 centreline thrust aeroplane with contra rotating, independent props? Darn sight safer than these 'conventional' twins, I'd have thought?