A Bell Helicopter concept in model form of an armed derivative of the XV-15 tiltrotor. This dated from the early/mid 1980’s and represented a ground attack aircraft… largely what the US Army was looking for in what became the LHX/RAH-66 Comanche program, just in tiltrotor form. As a tiltrotor, it would have had a much faster and more fuel efficient cruise, but a less efficient hover, than a helicopter. The Army turned out to not want tiltrotors for this application, and made sure that they were effectively excluded from the LHX competition.
Note the hand-written notation that missiles would only be fired in hover… otherwise, they would pass through the proprotor disk. However, it seems likely that missiles could be fired while the rotors were tiltedless than fully upwards, meaning that the craft could fire and move at a fair rate at the same time, just not at full speed.