The Harmon Der Donnerschlag (English: Thunderclap) is an American homebuilt aircraft that was designed and produced by Harmon Engineering of Howe, Texas. The aircraft was intended for amateur construction.[1]
| Der Donnerschlag | |
|---|---|
| Role | Homebuilt aircraft |
| National origin | United States |
| Manufacturer | Harmon Engineering Company |
| Status | Production completed |
| Variants | Harmon Mister America |
Design and development
editDer Donnerschlag features a wire-braced shoulder-wing, a single-seat open cockpit, fixed landing gear and a single engine in tractor configuration.[1]
The aircraft's 19.5 ft (5.9 m) span wing has two beam-type spars and employs a 16% airfoil at the wing root, tapering to a 12% airfoil at the wingtip. The standard engine used is the 75 hp (56 kW) Volkswagen air-cooled engine automotive conversion, driving a two-bladed wooden propeller.[1][2]
The aircraft has an empty weight of 350 lb (160 kg) and a gross weight of 600 lb (270 kg), giving a useful load of 250 lb (110 kg). With full fuel of 10 U.S. gallons (38 L; 8.3 imp gal) the payload is 190 lb (86 kg).[1]
The aircraft was later developed into the Harmon Mister America.[1]
Operational history
editBy October 2013 there were no examples registered in the United States with the Federal Aviation Administration and none may exist anymore.[3]
Specifications (Der Donnerschlag)
editData from Plane and Pilot[1]
General characteristics
- Crew: one
- Length: 14 ft 6 in (4.42 m)
- Wingspan: 19 ft 6 in (5.94 m)
- Empty weight: 350 lb (159 kg)
- Gross weight: 600 lb (272 kg)
- Fuel capacity: 10 U.S. gallons (38 L; 8.3 imp gal)
- Powerplant: 1 × Volkswagen air-cooled engine four cylinder, air-cooled, four stroke automotive-conversion engine, 75 hp (56 kW)
- Propellers: 2-bladed wooden
Performance
- Maximum speed: 120 mph (190 km/h, 100 kn)
- Cruise speed: 110 mph (180 km/h, 96 kn)
- Stall speed: 55 mph (89 km/h, 48 kn)
- Range: 500 mi (800 km, 430 nmi)
- Service ceiling: 10,000 ft (3,000 m)
- Rate of climb: 800 ft/min (4.1 m/s)
References
edit- ^ a b c d e f Plane and Pilot: 1978 Aircraft Directory, page 142-143. Werner & Werner Corp, Santa Monica CA, 1977. ISBN 0-918312-00-0
- ^ Lednicer, David (2010). "The Incomplete Guide to Airfoil Usage". Archived from the original on April 20, 2010. Retrieved October 10, 2013.
- ^ Federal Aviation Administration (October 10, 2013). "Make / Model Inquiry Results". Retrieved October 10, 2013.