mounted engines either side of the rotor mast was envisaged, and the P.74 was expected to offer information into the necessary ducting required hence the engine was mounted underneath the fuselage with ducts running up through the cabin. Testing and evaluation Ground testing in a static rig commenced in 1956, but the Oryx engines failed to develop full power and maximum gas flow. Even with modifications to the power units, the first flight was aborted when the P.74 failed to fly. This may have been providential as there were no escape provisions for the two pilots. The only entrance door was located at the rear on the port side. The primary test pilot was famously quoted as saying the hapless P.74 had, "...the cockpit, flying controls and engine controls... designed without any input from a pilot." The designers planned to fit a more powerful Rolls-Royce RB108 turbine, and a further development of a 10-passenger (P.105) variant was on the "drawing boards" when the nationalisation of the helicopter industry later that year resulted in the P.74 project being cancelled and the prototype scrapped. Variants P.74 Experimental helicopter with a rotor powered by two Napier Oryx gas generators, one built but failed to fly and was scrapped. P.104 Proposed variant with non-laminar-flow rotor blades, not built. P.105 Proposed improved variant with the Oryx generators moved above the cabin, not built P.113 Proposed improved variant of the P.74 with a Rolls-Royce RB108 engine and redesigned rotor system, not built. Specifications (P.74 as designed) See also References Notes Bibliography Apostolo, Giorgio. The Illustrated Encyclopedia of Helicopters. New York: Bonanza Books, 1984. . "Hunting Percival P.74: Research Test Vehicle Approaches the Flight Stage: a New Helicopter Philosophy." (PDF) Flight via flightglobal archive, 1955. Winchester, Jim. The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters. London: Amber Books Ltd., 2005. . P.74 1950s British experimental aircraft Military helicopters 1950s British helicopters Tipjet-powered helicopters