Once witnessed a departing Herk with one engine that wouldn't start. Having had at least two desperate attempts to "bump start" it by accelerating down the runway with one engine windmilling, it finally took off on three engines with a prop feathered.
Strange that it got as far as Nassau before the crew noticed and put it u/s ....... can't say I blame them.
Whatever, I'm sure the 3 donk takeoff was all legal and above board and cleared by the AOC.
Seeeeeeeing as he was on board