The Hiller YH-32 Hornet (company designation HJ-1) was an American ultralight helicopter built by

Hiller Aircraft Hiller Aircraft Company was founded in 1942 as Hiller Industries by Stanley Hiller to develop helicopters. History Stanley Hiller, then seventeen, established the first helicopter factory on the West Coast of the United States, located in Berkel ...

in the early 1950s. It was a small and unique design because it was powered by two Hiller 8RJ2B

ramjet A ramjet, or athodyd (aero thermodynamic duct), is a form of airbreathing jet engine that uses the forward motion of the engine to produce thrust. Since it produces no thrust when stationary (no ram air) ramjet-powered vehicles require an as ...

engines mounted on the rotor blade tips which weigh each and deliver an equivalent of for a total of . Versions of the HJ-1 Hornet were built for the

United States Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, ...

and the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

in the early 1950s. The Hiller Museum identifies the YH-32A, named the ''Sally Rand'', as the first

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attribute ...

gunship A gunship is a military aircraft armed with heavy aircraft guns, primarily intended for attacking ground targets either as airstrike or as close air support. In modern usage the term "gunship" refers to fixed-wing aircraft having laterally-mo ...

Design and development

The Hiller HJ-1 Hornet was an early attempt to build a jet-powered helicopter using ramjets. Before that there had been experiments with the

XH-26 Jet Jeep The American Helicopter XH-26 Jet Jeep (known as the XA-8 by its manufacturer) was an experimental tip jet helicopter developed in 1951 by the American Helicopter Company to meet a United States Army and Air Force (USAF) request for a collapsibl ...

tip rotor pulse jets. The HJ-1 ramjet tipped rotor propels the rotor and the aircraft. Unlike a conventional helicopter, this mechanically simple design avoids the need for a tail rotor. Unfortunately, the tip speeds on helicopter rotor blades are subsonic, and ramjets are inefficient at subsonic speeds due to low compression ratio of the inlets. Therefore, the Hornet suffered from high fuel consumption and poor range. Also, the vehicle suffered from low translational speeds, and the ramjet tips were extremely noisy. In the event of power loss, autorotation was found to be difficult due to the drag from the ramjet nacelles. The vehicle exhibited powerful lifting capacity, and there was some hope for military uses, but the high noise, poor range, and high night-time visibility of the ramjet flames failed to attract sales.

Operational history

The HJ-1 was evaluated by the United States Army as the YH-32, and the

as the XHOE-1. In 1957 two YH-32s were modified as the YH-32A for trials as armed helicopters. All the fibreglass cockpit fairings were removed and the tail was modified. The tests were successful in proving the viability of the helicopter as a weapons platform, but due to marginal performance, no further conversions or orders were placed. Also, versions were sent to the U.S. Army's DRC to be evaluated in one of their contests involving the research and development of a light weight, air droppable helicopter for air rescue and reconnaissance, and for a portable, easily put together, and fuel efficient 1 man observation and transport copter. It was competing against the Jet Jeep and its pulse jets. Overall the YH-32 won out over the Jet Jeep, but the concept was considered obsolete, and later the program was canceled.

Variants

;HJ-1 :Company designation, one prototype. ;YH-32 :United States Army, Similar to HJ-1 with two small v-shaped stabilizers, 14 built (2 prototypes and 12 production aircraft). ;YH-32A :Two YH-32s modified for trials as an armed helicopter. ;XHOE-1 :Three HJ-1s for evaluation by the United States Navy in

1951 Events January * January 4 – Korean War: Third Battle of Seoul – Chinese and North Korean forces capture Seoul for the second time (having lost the Second Battle of Seoul in September 1950). * January 9 – The Government of the Un ...

Aircraft on display

* 138652 – XHOE-1 on static display at the Udvar-Hazy Center of the

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. * 53-4663 – YH-32 in storage with the Classic Rotors Museum in

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. * 55-4965 – YH-32 in storage at the United States Army Aviation Museum at

Fort Rucker Fort Rucker is a U.S. Army post located primarily in Dale County, Alabama, United States. It was named for a Civil War officer, Confederate General Edmund Rucker. The post is the primary flight training installation for U.S. Army Aviators an ...

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. * 55-4969 – YH-32 on static display at the

Museum of Flight The Museum of Flight is a private non-profit air and space museum in the Seattle metropolitan area. It is located at the southern end of King County International Airport (Boeing Field) in the city of Tukwila, immediately south of Seattle.< ...

Seattle, Washington Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest region ...

. * 55-4973 – YH-32 airworthy at

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. * c/n 15 – YH-32 on display at the Classic Rotors Museum in

Ramona, California Ramona is a census-designated place (CDP) in San Diego County, California. The population was 20,292 at the 2010 census. The name ''Ramona'' also refers to an unincorporated community (with some plans to incorporate) that includes both the ...

. * Unknown ID – HJ-1 on static display at the Hiller Aviation Museum in

San Carlos, California San Carlos ( Spanish for "St. Charles") is a city in San Mateo County, California, United States. The population is 30,722 per the 2020 census. History Native Americans Prior to the Spanish arrival in 1769, the land of San Carlos was occu ...

. * Unknown ID – YH-32A on static display at the Hiller Aviation Museum in San Carlos, California.

Specifications (YH-32)

Notes

Bibliography

* Andrade, John. ''U.S. Military Aircraft Designations and Serials since 1909''. Hinckley, UK: Midland Counties Publications, 1979. . * Apostolo, Giorgio. ''The Illustrated Encyclopedia of Helicopters.'' New York: Bonanza Books, 1984. . * Display information at

. *''Flight'
page 725
2 November 1956

External links

Hiller Aviation Museum: The First 100 Years of Aviation

Video of Hiller HJ-1 Hornet hovering
{{USN helicopters Military helicopters H-32 Hornet Ramjet-powered aircraft 1950s United States helicopters YH-32 Tipjet-powered helicopters Aircraft first flown in 1950