Will it maintain that 7000 for 450nm on a single engine? That's something I never researched. I know the plane is going to be a lot more draggy on one, how badly does it hit your range?
Obviously I would hope to not be in that position. I have flow a C-401 around the Bahamas, Turks and Puerto Rico from Georgia so I have planned for this possibility before.
If I were to take my 310 on this mission, which I wouldn't to Bermuda but would the rest of the Caribbean, I have the following reference your question.
My range at 10,000 and 177KTAS is 1263nm to flame out. If at the half way point of 900nm I lost an engine after that fuel burn my single engine ceiling is a little above 8000. I would cruise the remainder of the flight at 7000. I would then be down to around 110KTAS conservatively burning around 20gph worse case.
Start with 163 gallons. By the 450 point I would have burned 65 gallons. The remaining 450 on single engine would burn 80 gallons. This would give an uncomfortable but make-able 18 gallons in the tank. These are conservative worse case numbers I feel.
If you encountered worse winds etc that would obviously quickly eat in reserves then from 10,000 I'd have 18 miles to glide after dual flame-out.
At that point with all that air in the tanks I should float for a bit while leisurely getting the raft and beer out for my time waiting on rescue.
Again, not a position I'd ever want to be in. PROVIDENCIALES to SAN JUAN is a much more comfortable 406nm and that's the farthest open water I've done flying a piston twin. FPR to Provo is 560nm with lots of divert spots on the way.
