EFW N-20

The EFW N-20 Aiguillon (in English: "Stinger") was Switzerland's first indigenous jet fighter aircraft. The Swiss Federal Aircraft Factory developed a design for a four-engined swept winged fighter following the end of the Second World War. During the test programme an unpowered glider was built and flown. A turbojet powered test aircraft, known as the Arbalète ("Crossbow"), also flew.

The N-20 design was not produced. Both the single Aiguillon and Arbalète airframes survive and are on public display at the Flieger-Flab-Museum, Dübendorf; the glider test aircraft was destroyed in an accident.

EFW N-20
Class Aircraft
Type Fighter
Manufacturer Eidgenössische Flugzeugwerke Emmen
Origin Switzerland
Country Name Origin Year
Switzerland 1952
ManufacturerName Production From Production To Quantity
Eidgenössische Flugzeugwerke Emmen 1 View

The aircraft was to be powered by four turbofan engines buried in the wings, with the bypass air feeding cold-air pipes each side of the engines, being routed through a combustion chamber where additional fuel could be burned as a form of reheat, or deflected though large slots on the upper and lower wings to act as aerodynamic flaps or thrust reversers. Two engines could be shut down in flight to increase range. It was planned that the N-20 would carry its armament in a detachable weapons bay, capable of carrying large loads of cannons, rockets or bombs.

It was initially planned that the aircraft's engines would be designed and built by the Swiss company Sulzer. The initial engine choice was a small turbojet, the Sulzer D45, with a thrust of 7.38 kN (1,660 lbf), which was abandoned in 1947. Only two prototype D45 engines were built in 1948. The first engine, D45.01 was used in a test rig between 1950 and 1951 and the second engine, D45.04 (of limited airworthiness) was used until 1955 in a test rig. The D45.04 is also part of the Dübendorf museum N-20 display.

The Armstrong Siddeley Mamba turboprop was then chosen as the basis for the N-20's engines, with the propeller reduction gear replaced by a low pressure compressor. This powerplant was named Swiss Mamba SM-1, the conversion was carried out in 1948 by EFW, with only six engines built (four fitted to the N-20 with two spares). One of the spare engines is today part of the Swiss Museum of Transport, at the Flieger-Flab-Museum Dübendorf.

Role Fighter aircraft
National origin Switzerland
Manufacturer Eidgenössische Flugzeugwerke Emmen
First flight 8 April 1952
Status Cancelled
Primary user Swiss Air Force
Number built 1

General characteristics

  • Crew: 1
  • Length: 12.5 m (41 ft 0 in)
  • Wingspan: 12.6 m (41 ft 4 in)
  • Height: 3.13 m (10 ft 3 in)
  • Wing area: 54 m2 (580 sq ft)
  • Empty weight: 9,000 kg (19,842 lb)
  • Gross weight: 8,709 kg (19,200 lb)
  • Powerplant: 4 × Sulzer Swiss Mamba turbofan, 6.2 kN (1,400 lbf) thrust each [6]


  • Maximum speed: 1,000 km/h (621 mph; 540 kn)
  • Range: 500 km (311 mi; 270 nmi)
  • Service ceiling: 11,000 m (36,089 ft)

End notes