The P.91 was a tip jet powered 2-seat (very) light helicopter, dsigned in 1954 to
meet the H.144T specification, which was won by Fairey Ultralight.
The P.105 was intended as a 10-seat derivative of the P.74. But when the
P.74 became a total failure, unable to lave the ground, the P.105 was
cancelled, too. A flying crane version was proposed, which then disappeared
together with the basic version.