High Quality Content by WIKIPEDIA articles! The Hiller YH-32 Hornet (company designation HJ-1) was an American ultralight helicopter built by Hiller Aircraft in the early 1950s. It was a small and unique design because it was powered by two Hiller 8RJ2B ramjet engines mounted on the rotor blade tips. Versions of the HJ-1 Hornet were built for the United States Army and the United States Navy in the early 1950s.