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

Hiller Aircraft Hiller Aircraft Corporation is an American private aerospace company, based in Firebaugh, California. It was founded in 1942 as Hiller Industries by Stanley Hiller to develop helicopters. History Stanley Hiller, then seventeen, established t ...

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

ramjet A ramjet is a form of airbreathing jet engine that requires forward motion of the engine to provide air for combustion. Ramjets work most efficiently at supersonic speeds around and can operate up to . Ramjets can be particularly appropriat ...

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 primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...

and the

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

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

Sally Rand Sally Rand (born Helen Gould Beck; April 3, 1904 – August 31, 1979) was an American burlesque dancer, stripper, vedette, and actress, famous for her ostrich-feather fan dance and balloon bubble dance. She also performed under the name B ...

'', as the first

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

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 ...

. The Hiller HOE-1 became the first production ramjet helicopter, and the Army and Navy flew a small number of these aircraft for a short time to test and evaluate the technology.

Design and development

The Hiller HJ-1 Hornet was an early attempt to build a jet-powered helicopter using ramjets, with work beginning in 1948. 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) is an experimental tip jet helicopter developed in 1951 by the American Helicopter, American Helicopter Company to meet a United States Army and Air Force (USAF) reque ...

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. The first Hiller Hornets were not ready for delivery until late 1954, due to Hiller certificating the aircraft to Civil Aviation Authority standards rather than military specifications.

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 Uni ...

Aircraft on display

* 138652 – XHOE-1 on static display at the

Udvar-Hazy Center The Steven F. Udvar-Hazy Center, also called the Udvar-Hazy Center, is the Smithsonian Institution, Smithsonian National Air and Space Museum (NASM)'s annex at Dulles International Airport in the Chantilly, Virginia, Chantilly area of Fairfax C ...

of the

National Air and Space Museum The National Air and Space Museum (NASM) of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to history of aviation, human flight and space exploration. Established in 1946 as the National Air Museum, ...

Chantilly, Virginia Chantilly is a census-designated place (CDP) in western Fairfax County, Virginia, United States. The population was 24,301 as of the 2020 census. Chantilly is named after an early-19th-century mansion and farm, which in turn took the name of an ...

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

Victorville, California Victorville is a city in Victor Valley in San Bernardino County, California. Its population as of the 2020 census was 134,810. Victorville is the principal city of a Victor Valley–based urban area defined by the United States Census Bureau: ...

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

Fort Novosel Fort Rucker is a United States Army post located primarily in Dale County, Alabama, United States. It was formerly named in honor of Chief Warrant Officer Michael J. Novosel, an Army aviator and Medal of Honor recipient. It was previously name ...

Ozark, Alabama Ozark is a city in and the county seat of Dale County, Alabama. As of the 2010 census, the population of the city was 14,907. Ozark is the principal city of the Ozark Micropolitan Statistical Area, as well as a part of the Dothan-Ozark Co ...

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

Museum of Flight The Museum of Flight is a private Nonprofit organization, non-profit Aircraft, air and Spacecraft, space museum in the Seattle metropolitan area. It is located at the southern end of Boeing Field, King County International Airport (Boeing Fi ...

Seattle, Washington Seattle ( ) is the List of municipalities in Washington, most populous city in the U.S. state of Washington (state), Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the List of Unit ...

. * 55-4973 – YH-32 airworthy at

Fantasy of Flight Fantasy of Flight is an aviation museum in Polk City, Florida. It opened in November 1995, to house Kermit Weeks' collection of aircraft that, until Hurricane Andrew damaged many in 1992, were housed at the Weeks Air Museum in Kendall-Tamiami E ...

Polk City, Florida Polk City is a city in Polk County, Florida, Polk County, Florida, United States. It is part of the Lakeland, Florida, Lakeland–Winter Haven, Florida, Winter Haven Lakeland-Winter Haven, Florida Metropolitan Statistical Area, metropolitan s ...

. * 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 21,468 at the 2020 census, up from 20,292 at the 2010 census. The name ''Ramona'' also refers to an unincorporated community of San Diego (with so ...

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

San Carlos, California San Carlos (Spanish language, Spanish for "St. Charles") is a city in San Mateo County, California, United States. The population is 30,722 per the 2020 United States census, 2020 census. History Native Americans Prior to the Spain, Spanis ...

. * 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 Single-rotor helicopters Aircraft with skid landing gear