WALTER VAN TILBORG MEMORIAL COLLECTION
No. 9533. McDonnell 65 XHJD-1 Whirlaway (44318) US Navy
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McDonnell 65 XHJD-1 Whirlaway

12/31/2009. McDonnell's interest in rotary wing flight goes back to 1944 when it acquired an interest in Platt Le Page Aircraft. Platt Le Page had been working on contra-rotating twin rotor helicopter projects under USAAC funding since 1938, resulting in the PL-3 XR-1A of 1941. Under McDonnell the interest in the dual rotor layout with was continued in the first US twin-engine helicopter, the two-seat XHJD-1 of 1946, developed for the USN.

The sole example, BuNo 44318, was originally conceived as an ASW helicopter but was actually built as a flying laboratory to confirm theories on various helicopter rotor parameters. It had side-by-side rotors mounted on outriggers extending from the engines which were themselves mounted on stub wings. In cruise flight the wings could support about ten% of the aircraft's weight. The rotor blades and direction of the rotation as well as other aerodynamic features of the aircraft were varied during the flight test program.

The original tail fin was subsequently supplemented with an externally braced horizontal control surface. The XHJD-1's main landing gear extended down from the engine nacelles and was externally braced; a tail wheel was also fitted. Extensive instrumentation was provided, while the power plant consisted of two 450 hp Pratt & Whitney R-985-AN-14B Wasp Junior radial engines.

The XHJD-1 (site files), named Whirlaway by McDonnell, first flew on April 27, 1946, shortly thereafter it became the XHJH-1 when the USN changed the McDonnell code letter from D to H. It was engaged in test and evaluation until June 1951, and flew with the outer panels of the outriggers both covered and uncovered. Rotor blades of various diameters could be fitted, as were horizontal tail surfaces.

Created December 31, 2009