As an ex Diezel 8 driver, I can tell you that there's no such thing as a 2 engine ferry....2 engine taxi on 2 & 3 yes, as somebody alse here pointed out, the EDP's are on these engines. It's saves almost next to nothing on fuel as you'll have to cross bleed start the other 2 remaining. The pneumatic manifold on the diezel 8 is known to leak a lot, therefore a lot of thrust from the other engines is required. 3 engine ferry's does not require a "special crew". All crews are trained for 3 engine ferry flights in the simulator, at least for all the diezel 8 operators I worked for. Also there's a little thing called 3 engine ferry ops manual, these "special crews" read them before commencing the flight and go through a very extensive briefing. Hope this clears some about the mighty 8...Oh almost forgot, you can actually taxi the 8 on 1 & 4 only, as the aux pump feeds the whole general system, not a good practice, but yes, you could....
Nubboy:
I think I know who you mean, with that 707 taking off on 3 to get the 4th starting.....Good ol' Sport M.........