Hiller Ten99
Role	Experimental helicopter Type of aircraft
National origin	United States
Manufacturer	Hiller Aircraft
First flight	July 16, 1961[1]
Number built	1

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

Design and development

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.

Specifications

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)