your answer is surprising, somehow. I always thought a tilt-wing aircraft would be much simpler, given that the engines don't need a delicate tilting mechanism; and when the engines and the wing form a unit, a driveshaft connecting the engines would also be easier to build.
Then, the engine tilting mechanism has to fit into the already room-restricted wing, while the crown area of our tilt-wing aircraft would offer ample space for a tilting mechanism.
|Quoting rwessel (Reply 1):|
But probably the biggest disadvantage of the tilt-wing design is that you'd have more issues on the transition to horizontal flight - the V-22's wing can start producing lift as soon as it starts moving forward, a tilt-wing is going to be stalled until the wing's alpha drops to about 14 degrees.
Well, at first I had a completely impractical thought about how to solve this...
Helicopters drop their nose in order to gain forward speed. The same could be done with a tilt-wing aircraft - the wing tilt relative to the fuselage is still 90°, but the nose drops, the wing AoA is decreased, and the engines begin to produce a partial forward thrust in addition to the lift.
The "impractical" part comes in when dropping the nose of the aircraft: I first thought of moving weights inside of the fuselage crown because Zeppelin airships had the same method of controlling their attitude...
Well, now I've read about the various tilt-wing models and most (if not all of them) feature a tail rotor for that purpose.
I'm not sure, but I think a tilt-wing flying thingamajic would be better at STOL takeoffs. I'd firewall the throttles and gradually tilt the wing from initally 20° to about 45° - the wings will be stalled but they still produce lots of lift (at a terrible efficiency, though). But with a thrust-weight ratio > 1, this is a rather academic problem.
I remain amazed about the variety of contraptions designed and tested during the cold war and I'm sure a more economical tilt-wing or a tilt-rotor aircraft would have been great for SAR duty, for example...
[Edited 2012-01-10 11:01:21]
Keeping calm is terrorism against those who want to live in fear.