"The 4-engine version is the quad tilt rotor or QTR"
With a shaft required from front wing/rotor set to rear wing/rotor set, that would have to be some drivetrain - unless they "assume" no total front/rear eng failure...
"Lots of fun stuff on Bell's other tilt studies at AIAA unbuilt VSTOL."
Interesting stuff here. I guess they opted early on for a distributed powertrain to keep drivetrain mass down (torque limit on one engine operation). I still bet that G/Box and Drivelines make up a significant proportion of the empty weight.
"MH-47E ... 40 Million Dollars vice the 105 (plus creep) million Dollar price tag of the Osprey"
Tandems have been around a while now since Piasecki's "Flying Banana". I imagine that time will (eventually) see this technology cheapen too, as it proves itself (or otherwise
).
"Chinooks maintained a 99-percent mission readiness rate."
That's an impressive statistic!
Mart