Sikorsky H-5/S-51



This photograph may not be used or published, neither commercially nor for other purposes, in any form, including but not restricting to the Internet, magazines and books, without the photographer's permission. For all inquiries please contact the photographer by e-mail or by other means. 

The first helicopter to be assigned to NAS Grossse Ile and was only there long enough for its first inspection and then was replaced by the Hiller HTE. They were built in large numbers was a derivative of the Sikorsky R-5, which started out as a tandem two-seater. The first of five prototypes flew on 18 August 1943 powered by a 450hp Wasp Junior radial. This was followed by 25 YR-5A pre-production models, two of which were assigned to the Navy under the designation HO2S-1. While production of the R-5A was getting under way (34 built), five pre-series aircraft were converted into the R-5E, which had dual control, while at least 20 modified R-5As were later given new, 600hp Wasp Junior engines and redesignated R-5D. From the latter, the S-51 was developed, with a slightly enlarged four-seat cabin and a tricycle landing gear.

A total of 300 S-51s were built, some with 450hp engines, others with 600hp engines and larger diameter three-blade rotors. The military versions were designated R-5F (11 to the USAF), H-5G (38 fitted with a rescue hoist), H-5H (17 with amphibious wheel/pontoon landing gear), HO3S-1 and S2 (90 in all, naval rescue version). The S-51 had a three-blade articulated rotor, the blades of which could be folded back to facilitate stowage. The first aircraft had manual pitch control; this was later replaced by a hydraulic system. The cabin diameter was also increased.


Manufacturer Sikorsky
Designation HO2S-1; HO3S-1G
Other Designations: R-5A; H-5; S-51
Cost $91,977.00
DESCRIPTION Pilot and three passengers or two stretcher cases
POWER PLANT One 450 hp Pratt and Whitney R985 radial engine.
Rotor diameter 49 ft;
Length 57 ft 1 in.
Height 13 ft.
Climb 15 mins to 10,000 ft.
Service ceiling 14,400 ft.
Range 360 miles.
Blade Area 3 blades; 115 square feet total
Tail Rotor Diameter 8' 5" (3 blades total)
Fuel Capacity 100 gallons
Top Speed 107 mph at 1,500 feet
Cruising Speed 85 mph at 1,500 feet
Sea Level Climb 1,240 feet per minute
Range 275 miles at 1,500 feet
Empty Weight 4,050 lbs.
Gross Weight 5,500 lbs.
Hover Ceiling 3,100 feet
Service Ceiling 14,800 feet

Copyright 2005NASGIVM  All rights reserved.
Revised: December 22, 2005