Hiller UH-12 Raven standard observation helicopter

Young Stanley Hiller Jr flew his first helicopter, the coaxial-rotor XH-44, in August 1944. He then made a completely fresh start, with single main rotor with hanging control column, and, by way of UH-5 Commuter prototypes, perfected a patented Rotor-Matic control system with the cyclic stick connected not to the main blades but to short auxiliary blades set at 90° and rotating as part of the main rotor. The production development was designated Model 360, and this was simplified into the open-cockpit UH-12A which was evaluated in early 1950 by the US Army as the YH-23 (later given family name Raven) and by the Navy as the HTE-2.

Adopted as standard observation helicopter, the Army bought 100 H-23s with optional dual control and with equipment for carrying two stretcher casualties in external panniers. Five H-23As were sold to the USAF, while the Navy bought 16 HTE-1 trainers followed immediately by large batches of HTE-2s with quad landing gear or skids of which 20 were supplied by Mutual-Defence Aid to the Royal Navy. A batch of 273 H-23B for the Army had wheeled skids instead of tricycle gear, most going to the school at Ft Wolters. The H-23C (145 built) had three seats side-by-side, one-piece canopy, metal blades and a new hub. The Army then took 483 H-23Ds with more power and overhaul life increased from 600 to 1,000 hours. A batch of 22 H-23Fs were four-seaters, and the last model was the OH-23G with autostabilizer and a new rotor, bringing production to beyond 2,000 of which 24 went to Canada as CH-112 Nomads.

Hiller UH-12 Raven Specification

Hiller Raven
Name: Hiller UH-12 Raven
Role: Light helicopter
First Flight: 1946. Introduction: 1948
Primary User: USAF
Service: Retired
Crew: 2
Capacity: 2
Length: 27 ft 9 in (8.47 m) Rotor Diameter: 35 ft 5 in (10.80 m)
Height: 9 ft 9 in (2.99 m) Weight: 1,816 lb (825 kg)
Loaded Weight: 2,300 lb (1,0250 kg) Max. Weight: 2,700 lb (1,227 kg)
Powerplant: 1 × Lycoming VO-435-23B2 Power: 250 hp (187 kW)
Max. Speed: 95 mph (153 km/h, 83 knots) Range: 197 mi (317 km, 171 nmi)
Rate Of Climb: 1,050 ft/min (5.3 m/s) Service Ceiling: 1,050 ft/min (5.3 m/s)
Number Built: 2000 Unit Cost: Unknown

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