Built in 1961, this was the prototype of a turbine-powered transport heli-copter using dynamic components of the earlier Hiller models, but with an entirely new, more capacious fuselage (six seats).
G.Apostolo "The Illustrated Encyclopedia of Helicopters", 1984
Flight-tested in secrecy over the past six months, a new six-seat utility helicopter has just been announced by Hiller. Powered by the Canadian Pratt & Whitney PT6 of 500shp, the newcomer is designated the Ten 99 (or, as the manufacturers rather inelegantly render it "Ten99"). The PT6 is the only North American light helicopter turbine to have passed the 50hr US Government qualification test, and the new Hiller is the first aircraft to be powered by it (excluding the Beech 18 test-bed).
A private venture, the Ten 99 - "the smallest big helicopter flying" - is intended for a wide variety of roles, including fleet utility work, Marine Corps assault tasks, and general-purpose civil passenger and freight duties. Although no greater in overall dimensions than the Hiller 12E, it has twice the seating capacity; payload is in excess of 450kg.
Unique in the light-helicopter class is the provision of large aft-loading clamshell doors for the 2.83m3 box-like cargo compartment. In addition there are four doors for passengers and crew and to assist in through-loading of the cargo section.
Studies for the Ten 99 began late in 1958, and preparations for production have included market evaluation, wind-tunnel testing and the manufacture of a full-scale mock-up which has been transported to various places in order to obtain reactions from prospective customers. Application for type certification was made to the | FAA last summer.
"Flight", 16 November 1961
Technical data for 1099
Engine: 1 x Pratt & Whitney PT6 turboshaft, rated at 410kW, main rotor diameter: 10.86m, length: 12.57m, fuselage length: 8.05m, height: 3.18m, take-off weight: 1588kg, empty weight: 862kg