Sans,
The 22 concept began a long time ago......and when the latest Sikorsky thing comes to being in a few years it will have been around since the late 70's. The S-69 ABC first flew in July 1975. Had the US Government picked up the full cost of Flight Testing back then.....the project would have been much further along but the decision had been made to go with the Tilt Rotor and not the ABC concept.
We see a renewed interest in the Sikorsky design concept today as the Tilt Rotor design does not lend itself for use as an Attack Helicopter.....which the ABC concept is very well suited.
The XV-3 first flew in March 1955 and was already in the Museum when I started flying Helicopters in 1967. The V-22 is just the latest of the line.
The days of six months from initial sketch to start of production ended with the P-51.
Last edited by SASless; 2nd Jan 2014 at 20:23.