The Struchen (strew-shen) single seat ultralight helicopter was designed and built by Fred Struchen of North Vancouver. He used a combination of helicopter, motorcycle, automobile and hardware store components that were modified as required.
The powerplant is a Honda Civic engine, cooled by a motorcycle radiator. The drive belt came from a Harley Davidson, while the transmission is from a Yamaha and the canopy is created from a residential skylight. Numerous precision parts were machined or modified by the builder.
The Struchen is complete and fully operational, but it is believed that it was never registered or flown by the builder, although it has done low-altitude “hover” tests.
This aircraft was donated to a Canadian museum by its builder in 1996.
A complicated helicopter with two contrarotating fabric-covered rotors of eight and six blades, built by F. Sternemann and Dr.ing. W. Siebert of Hamburg, Germany, in 1910 and tested at the Wandsbecker Exerzierplatz.
A single seat open frame helicopter first flown on 16 October 1990. Aluminium tube frame with all parts bolted or pop riveted together. Engine: 64-110 hp Rotax or Hirth.
Engine: 88 hp Max speed: 95 mph Cruise speed: 65 mph Range: 105 sm ROC: 1000 fpm Service ceiling: 9,000 ft Fuel cap: 8 USG Empty wt: 430 lbs Gross wt: 895 lbs Height: 7.33 ft Length: 13.5 ft Disk span: 20 ft Disk area: 314 sq.ft Seats: 1
Wilbur Staib (1914–1993) was a self-taught aircraft designer from Diamond, Missouri. Staib served as a flight instructor during the Second World War at Chanute, Kansas flying PT-14s. Staib designed and built five different “LB” (Little Bastard) aircraft and a helicopter, of which several had the title “world’s smallest” at their time of construction. Staib flew his aircraft in airshows with the title “The Diamond Wizard”.
Wilbur Staib converted himself from motorcycle and speed boat passions in the late twenties, he has since come up with some mighty fine air-planes. He originally designed and built the three biplanes for Merrill L. Carpenter, which are known as the Carpenter “Specials”. Wilbur starts building by drawing chalk lines on the floor, and by periodically referring to his floor “drawing-board”, proceeds to build an airplane. There were four late biplanes, which all bore the Staib name. All were fully aerobatic and guaranteed not to come apart at any speed or attitude, with terminal velocity tests to back them up.
Earlier, in August 1978, P.Z.L. Swidnik concluded an agreement with the Spitfire Helicopter Company of Media, Pennsylvania, US allowing them to market a modified version of the Kania (itself an Mil Mi-2 verion) in Western countries under the name Spitfire Taurus. This differed primarily from the standard Polish version by introducing uprated Allison 250-C28 turboshaft engines, each with a take-off rating of 373kW fed by a large common intake; revised nose contours and sporting a ventral fin. However, the company has since gone out of business, and it is not known if any conversions were completed.
Taurus Engine: 2 x Isotov 350P, 400 shp TBO: 3500 hr Main rotor: 48.3 ft Seats: 9 Length: 39.2 ft Height: 12.3 ft Max ramp weight: 7400 lb Max takeoff weight: 7400 lb Standard empty weight: 5166 lb Max useful load: 2234 lb Max landing weight: 7400 lb Max sling load: 1763 lb Disc loading: 4 lbs/sq.ft Power loading: 9.3 lbs/hp Max usable fuel: 1472 lb Max rate of climb: 900 fpm Service ceiling: 13,300 ft Hover in ground effect: 6,900 ft Hover out of ground effect: 7900 ft Max speed: 147 kt Normal cruise @ 3000 ft: 128 kt Fuel flow @ normal cruise: 435 pph Endurance @ normal cruise: 2.8 hr
The Spitfire Mark I was a utility helicopter built in the United States in the late 1970s and intended for series production. In essence, the Mark I was an Enstrom F-28 that was modified to use an Allison 250 turboshaft engine and geared transmission in place of the original piston engine and system of vee belts. The resulting powerplant installation was lighter and more compact, which allowed for additional cargo or fuel.
Spitfire Helicopters’ parent company, Fetsko Aviation Sales and Transportation began work on the prototype in January 1976, and on a number of pre-production aircraft in February 1977. Fetsko displayed a mockup of the concept at the National Maintenance and Operations Meeting at Reading, Pennsylvania in June 1976.
The prototype (registered N4890) first flew in December 1978. By May 1979, Spitfire had supplemental approval for the turbine conversion and by July, the company reported that it had sold 42 examples of the Mark I and Mark II and expected to build 60 aircraft during 1980. The engine installation on production models was to be slightly further forward than on the prototype.
The Spitfire II derivative of the Enstrom uses a new four seat front fuselage and the Allison engine with Enstrom rotor and rear fuselage.
Other projects included Spitfire Mark IV with auxiliary propulsion engines at tips of stub wings.
However, Spitfire remained dependent on Enstrom to supply airframes for remanufacture, and Enstrom distanced itself from the project somewhat. Competing plans by Enstrom and Spitfire to market Polish-built Mil Mi-2 helicopters in the United States might have contributed to the friction. In Spitfire’s version of the deal, Polish manufacturer PZL-Świdnik would also contribute to the Spitfire manufacturing efforts. By November 1979, Enstrom refused to supply airframes to Spitfire.
The situation improved somewhat in the 1980s, and Spitfire president Jack Fetsko reported in May 1983 that relations with Enstrom had improved to the point where the two companies could “talk programs”. By that time, costs had increased from $US 165,000 expected in 1979 to $US 285,000 but Spitfire had taken deposits for 50 Mark Is, and had a firm sale for the first production aircraft. Together with companies Sodian and Soprea, Spitfire formed a new venture, Spitfire Helicopters International, to manufacture the Mark I and Mark II in Málaga, Spain.
Nothing came of the joint venture, and Spitfire’s attempts to market F-28 derivatives came to an end. In the 1990s, Enstrom marketed its own turbine-powered version of the F-28 as the Enstrom 480.
Mark 1 Engine: Allison 250-C20B, 420 shp TBO: 3500 hr Main rotor: 32 ft Seats: 3 Length: 29.4 ft Height: 9.2 ft Max ramp weight: 2350 lb Max takeoff weight: 2350 lb Standard empty weight: 1292 lb Max useful load: 1058 lb Max landing weight: 2350 lb Disc loading: 2.9 lbs/sq.ft Power loading: 5.6 lbs/hp Max usable fuel: 469 lb Max rate of climb: 1550 fpm Service ceiling: 15,000 ft Hover in ground effect: 13,400 ft Hover out of ground effect: 8000 ft Max speed: 112 kt Normal cruise @ 3000 ft: 96 kt Fuel flow @ normal cruise: 180 pph Endurance @ normal cruise: 2.4 hr Range: 308 mi
Mark II Tigershark Engine: 420hp Allison 250-C20B Rotor: 31’11” Useful load: 1175 lb Max speed: 135 mph Cruise: 120 mph Seats: 4
Mark IV Engine: 420hp Allison 250-C20B Rotor dia: 33’4″ Length: 30’0″ Useful load: 2100 lb Max speed: 215 mph Cruise: 201 mph Range: 482 mi Seats: 4-5
USA Based at Media, Pennsylvania. In January 1975 began design of Spitfire Mark I light helicopter, developed from Enstrom F-28A but with turbine powerplant. Other projects included Spitfire Mark II helicopter with additional cabin space and more engine power, and Spitfire Mark IV with auxiliary propulsion engines at tips of stub wings.
The commercial rights of the Helicom H-1 were sold to Southern Pacific Aircraft Co and then to International Helicopter Inc of Mayville, New York, with the machine being refined along the way as the Commuter II.
All Aero 