Hiller Ten99

The Hiller Ten99 (also known as the Hiller 1099) was an American 1961 experimental helicopter, created by Hiller Aircraft.

Hiller Ten99
Hiller Helicopter (3030845194).jpg
Role Experimental helicopter
National origin United States
Manufacturer Hiller Aircraft
First flight July 16, 1961[1]
Number built 1

Design and developmentEdit

The helicopter seated six and was similar to other helicopters by Hiller, but featured a larger, box-shaped cabin. It has four doors, and a set of clamshell doors on its aft side.[2] The aircraft was powered by a Pratt & Whitney Canada PT6, and in July 1961, was the first aircraft to have been powered solely by a PT6 engine. The Ten99 was developed for a United States Navy Assault Support Helicopter program. However, the Navy eventually selected the Bell HU-1 instead.[3] A civilian model was proposed, but not produced, and the project was eventually abandoned.


Data from Jane's All The World's Aircraft 1965–66[1]

General characteristics

  • Capacity: 6 people
  • Length: 41 ft 3 in (12.57 m) (overall length)
  • Height: 10 ft 5 in (3.18 m)
  • Empty weight: 1,900 lb (862 kg)
  • Max takeoff weight: 3,501 lb (1,588 kg)
  • Powerplant: 1 × Pratt & Whitney Canada PT6 Turboprop, 550 hp (410 kW)
  • Main rotor diameter: 35 ft 8 in (10.86 m)
  • Main rotor area: 997 sq ft (92.6 m2)


  1. ^ a b Taylor, John W R (1966). Jane's All the World's Aircraft 1966-67. London: Sampson Low, Marston & Co. Ltd. p. 227.
  2. ^ "PS Picture News: Squared-off Helicopter". Popular Science. Bonnier Corporation. 180 (2): 73. February 1962. ISSN 0161-7370.
  3. ^ Fleming, William A.; Richard A. Leyes (1999). The history of North American small gas turbine aircraft engines. AIAA. p. 447. ISBN 978-1-56347-332-6.