The design of the Horten 229 was in response to the Luftwaffe's call for a light bomber capable of meeting the "3◊1000" requirement; namely to carry 1,000 kilograms (2,200 lb) of bombs a distance of 1,000 kilometres (620 mi) with a speed of 1,000 kilometres per hour (620 mph).
Already famous for their flying wing design, the Horten brothers concluded that their low-drag flying wing design could meet all of the goals. They put forward their private project, the H.IX, as the basis for the bomber. The Government Air Ministry approved the Horten proposal, but ordered the addition of two 30 mm cannons, as they felt the aircraft would also be useful as a fighter due to its estimated top speed being significantly higher than that of any Allied aircraft.
Photo byToeknee25 / commons.wikimedia.org
Originally designed for the BMW 003 jet engine, but as that engine was not quite ready, the Junkers Jumo 004 engine was used. A drogue parachute slowed the aircraft upon landing. The pilot sat on a primitive ejection seat. The H.IX was of mixed construction, with the centre pod made from welded steel tubing and wing spars built from wood.
The first prototype H.IX V1, an unpowered glider with fixed tricycle landing gear, flew on 1 March 1944. The flight was successful but the design was taken from the Horten brothers and given to Gothaer Waggonfabrik. The Gotha team made some changes: they added a simple ejection seat, dramatically changed the undercarriage to enable a higher gross weight, changed the jet engine inlets and added ducting to air-cool the jet engine's outer casing to prevent damage to the wooden wing.
Impressed by the design, the Luftwaffe ordered 40 aircraft from Gothaer Waggonfabrik. With the end of the war approaching a Horten glider and the Ho 229 V3, which was undergoing final assembly, were captured by American forces and transported by sea to the United States as part of Operation Seahorse for evaluation.
The only surviving Ho 229 airframe, the V3-and the only surviving World War II-era German jet prototype still in existence-has been at the Smithsonian National Air and Space Museum's Paul E. Garber Restoration Facility in Suitland, Maryland, U.S. In December 2011, the National Air and Space Museum moved the Ho 229 into the active restoration area of the Garber Restoration Facility and is being reviewed for full restoration and display.
General characteristics Crew: 1
Length: 7.4 m (24 ft 3 in) chord at centre-line
Ho 229A: 7.47 m (24.5 ft)
Wingspan: 16.8 m (55 ft 1 in)
Ho 229A: 16.76 m (55.0 ft)
Height: 1.1 m (3 ft 7 in) cockpit height
Ho 229A: 2.81 m (9 ft 3 in) overall height
Wing area: 52.8 m2 (568 sq ft)
Ho 229A: 50.2 m2 (540 sq ft)
Aspect ratio: 7.8
Airfoil: 13% thickness
Empty weight: 4,844 kg (10,679 lb)
Ho 229A: 4,600 kg (10,100 lb)
Max take-off weight: 6,876 kg (15,159 lb)
Ho 229A: 8,100 kg (17,900 lb)
Fuel capacity: 1,700 kg (3,700 lb)
Powerplant: 2 ◊ Junkers Jumo 004B turbojet engine, 8.83 kN (1,990 lbf) thrust each
Performance Maximum speed: 960 km/h (600 mph, 520 knots)
Ho 229A: 950 km/h (590 mph; 510 knots) / M0.77 at sea level ; 977 km/h (607 mph; 528 kn) / M0.92 at 12,000 m (39,000 ft)
Cruise speed: 900 km/h (560 mph, 490 knots)
Never exceed speed: 1,000 km/h (620 mph, 540 kn)
Take-off speed: 150 km/h (93 mph; 81 knots)
Landing speed: 130 km/h (81 mph; 70 knots)
Range: 1,900 km (1,200 mi, 1,000 nmi) maximum
Rate of climb: 22 m/s (4,300 ft/min)
Wing loading: 130 kg/m2 (27 lb/sq ft)
Guns: Ho 229A: 2x 30 mm (1.181 in) MK 108 cannon