A 1969 Bell Helicopter design for a high speed stowed-rotor tiltrotor. This was meant for USAF search and rescue and featured gun turrets fore and aft (each with a Minigun) and four turboshaft engines under the wings. Doubtless the gearing from the engines up through the pylons and along the wings to the nacelles would have been an engineering nightmare. But if it worked, it would have resulted in a tiltrotor with the hover performance of the V-22 and a cruise speed of 400 knots.
An article on the similar D270-900-112 (the main visual difference being that the engines were separately podded) was included in US VTOL Projects #1.
I have made the much-larger full-rez scan of the cutaway available to $10+ APR Patreon patrons. If this sort of thing is of interest, please consider signing up for the APR Patreon.
