F-28 is a single-engined light trainer or utility helicopter designed and developed by Enstrom Helicopter Corporation of the US. Image courtesy of Ahunt.

F-28 is a single-engined light trainer or utility helicopter designed and developed by Enstrom Helicopter Corporation of the US. Image courtesy of Ahunt.

 The F-28 is fitted with tubular skid type shock absorbing landing gear. Image courtesy of Ahunt.

The F-28 is fitted with tubular skid type shock absorbing landing gear. Image courtesy of Ahunt.

 F-28A parked at the Shoreham Airport, England. Image courtesy of MilborneOne.

F-28A parked at the Shoreham Airport, England. Image courtesy of MilborneOne.

The Enstrom F-28 light trainer or utility helicopter can execute troop transport, military and civil training, agricultural crop dusting, aerial surveys and law enforcement missions in all climatic conditions. Approximately 1,200 F-28s were built until 2007.

The maiden flight of the first F-28 prototype took place in November 1960. The first production aircraft completed its first flight in May 1962. It was certified by the Federal Aviation Administration (FAA) in 1963 and entered service in 1965.

Variation models of the F-28 aircraft

"The Enstrom F-28 light trainer or utility helicopter can execute troop transport, military and civil training."

The F-28 has seven variants, namely the F-28A, T-28, F-28B, F-28C, F-28C-2, F-28F Falcon and F-28F-P Sentinel.

The F-28A is the first production rotorcraft powered by Avco Lycoming HIO-360-C1A engine rated at 153kW of output power. Its production began in 1965 and stopped in February 1970. The variant was certified in May 1968 with production resuming in 1971.

The T-28 is an upgraded version, equipped with a Garrett AiResearch TSE36-1 turbine engine. It was introduced in 1968 but did not enter the production phase. The F-28B is a turbocharged version.

The F-28C is an advanced model of the F-28A, equipped with an advance 153kW Avco Lycoming HIO-360-E1AD engine, a Rajay 301-E-10-2 turbocharger and a two piece windscreen. It was introduced in 1975.

The F-28C-2 is an overhauled version of the F-28C, fitted with a single piece bubble shaped glass canopy and a pedestal central instrument console for meliorating the crew visibility.

The F-28F Falcon is built by upgrading the F-28C with 168kW HIO-360-F1AD engines, large vertical stabilisers and a throttle correlator. The variant was introduced in 1981.

The F-28F-P Sentinel is fitted with a forward looking infrared camera, Spectrolab SX-5 searchlight and siren system to carry out surveillance and aerial photography missions. The variant entered service with Pasadena Police Department in October 1986.

Orders and deliveries of the Enstrom F-28

Customer orders for the F-28 include: Fresno Police Department (135), Peruvian Army (ten) and Colombian Air Force (12).

Features of the light trainer aircraft

The F-28 features a steel tube welded pylon assembly to which a composite cabin structure and a semi-monocoque aluminium tailboom are attached.

The welded pylon assembly houses engines, transmissions and fuel tanks and renders anchorage points for the landing gear. The tailboom incorporates two bladed tail rotor and vertical tail surfaces.

The helicopter is fitted with a three bladed main rotor, tubular skid type shock absorbing landing gear, two passenger doors, a large cargo door and engine driven alternator.

It also houses two 151 litre external fuel tanks, auxiliary power unit plug, starter warning and low voltage warning lights, anti-collision and nose mounted landing lights.

Cabin of the utility helicopter

The 1.54m wide cabin accommodates two passengers and a flight crew in three abreast seating configuration. It is built of alloys and glass fibre materials.

"The maiden flight of the first F-28 prototype took place in November 1960."

The aircraft is fitted with a large bubble shaped glass canopy, two overhead windows, two chin windows and two door windows to render panoramic view to the crew and passengers.

The avionics suite installed in the F-28 includes airspeed indicator, altimeter, standby compass, rotor or engine tachometer and ball indicator. The rotorcraft also houses air temperature gauge, gearbox temperature gauge, fuel flow gauge, oil pressure gauge, ammeter, cylinder head temperature gauge and fuel quantity gauge.

Other optional equipments include PS Engineering PM 3000 VOX intercom, Garmin GMA 340 audio panel, Garmin GNS 430 GPS, Garmin GTX 327 transponder, King KR87 automatic direction finder, AK-450 emergency locator transmitter, KRA 10A radar altimeter and King KI-208 voice over recorder.

Engines of the widely used aircraft

The F-28 is powered by a single Lycoming HIO-360-F1AD piston engine rated at 168kW of output power. It is equipped with ALU-8421-LS alternator, D4LN-3200 magneto, Skytech 149-24HT starter, RSA-5AB1 fuel injector, RG17980-R fuel pump and RHB-32S spark plug.

Performance of the Enstrom F-28 light trainer or utility helicopter

The F-28 can climb at the rate of 7.4m/s. The maximum and cruise speeds of the helicopter are 180km/h and 164km/h respectively.

The range is 446km and the service ceiling is 3,660m. The maximum endurance of the aircraft is 3.5 hours.