Enstrom Helicopter Company Enstrom F-28
Experimental pre-production prototype F-28 in flight, November 1962
The Enstrom F-28 and 280 are a family of small, light piston-engine powered helicopters produced by the Enstrom Helicopter Corporation. Enstrom Helicopter Corporation was established in 1959 to develop and produce light helicopters, based on Rudy Enstrom’s initial design work.
Extensive development and certification efforts led to the start of production of the F28 helicopter in April 1965; development of the turbine-powered model was initiated in 1988, culminating in certification of the TH-28 in September 1992 and the 480 in December 1994, to FAR Part 27 standards.
Since delivering their first helicopter in 1965, Enstrom Helicopter had produced approximately 1,200 aircraft by 2007.
Designed and built by Rudy J. Enstrom, the Enstrom F-28 light helicopter was flown in experimental form on Nov. 12, 1960, as a two-seat machine with a two-bladed main rotor and an un-skinned tubular rear fuselage.
It was followed into the air, on May 26, 1962, by the first of two three-seat pre-production examples, and the production version appeared in the autumn of 1963.
The F-28 was a conventional light helicopter having a light alloy/fiberglass cabin section with an all-metal, semi-monocoque tail boom, with a skid landing gear and tubular metal tail rotor protector, as well as a horizontal stabilizer with fins at tips. It has a high inertia, three-blade, 32-ft (9.8-m) diameter, fully articulated rotor head with non-folding blades attached by retention pin and drag link with control rods passing inside a tubular rotor shaft to the swashplate, which is inside the fuselage. A two-blade teetering tail rotor is used for anti-torque and directional stability. The F-28 was powered by a 180 hp Avco Lycoming four-cylinder, direct drive, O-360-A1A piston engine with a multi-groove belt drive used to transmit power from the horizontally mounted engine to transmission.
The company produces three models, the F-28, the more aerodynamic 280 and the turbine-powered 480, each with their own variants. The F-28 and 280 both use Lycoming piston engines, virtually identical to those found in general aviation fixed-wing aircraft.
F-28A: introduced in 1968, the F-28A was powered by a 205 HP Avco Lycoming HIO-360-C1A engine. Production was discontinued in February 1970, when the R.J. Enstrom Corporation ceased operations, but restarted in 1971 when it reformed as the Enstrom Helicopter Corporation.
The Enstrom 280 Shark: developed in 1973 as a luxury version of the F-28A, the Shark introduced a more streamlined cabin-section, dorsal and ventral vertical tail surfaces with small endplate fins at the ends of the small horizontal tail planes; FAA certification was achieved in September 1974.
F-28C/280C: improved versions, introduced in 1975, powered by the 205 HP Avco Lycoming HIO-360-E1AD engine with a Rajay 301-E-10-2 turbocharger; the tail rotor was moved to the port side of the fuselage and the direction of rotation reversed. The F-28C-2 introduced a one-piece windscreen and a pedestal central instrument console for improved forward and downward vision. Production ceased in November 1981.
F-28F Falcon/280F: FAA certificated in January 1981, the F-28F and 280F were powered by the turbocharged 225 HP Avco Lycoming. HIO-360-F1AD engine F-28F-P Sentinel: dedicated police version of Model 280F developed for Pasadena Police Department and fitted with special equipment including a searchlight. First delivery in October 1986.
In 2019, the Enstrom Helicopter Corporation celebrated its 60th anniversary. It has produced over 1,300 helicopters, which operate in over 50 countries around the world — and it is still manufacturing F-28s (now upgraded to the F-28F version), along with the 280FX and turbine 480B.
Today, Enstrom is a wholly owned subsidiary of a Chinese company, Chongqing General Aviation Group Co., Ltd. (CGAG), but it is still located in the same location in Menominee.
For much more detailed reading on the Enstrom F-28 helicopter, please refer to: https://verticalmag.com/features/how-the-f-28-was-the-fulfilment-of-rudy-enstroms-long-held-dream/
Description: Peter Noell
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