Federal Aircraft Plant N-20
| EFW N-20 Aiguillon | |
|---|---|
 N-20 prototype in the Aviation and Flab Museum |
|
| Type: | Prototype of a jet fighter |
| Design country: | |
| Manufacturer: | |
| First flight: |
Never happened |
| Commissioning: |
Development canceled in 1953 |
| Production time: |
Was never mass-produced |
| Number of pieces: |
1 |
The EFW N-20 Aiguillon was a Swiss jet aircraft project of the Federal Aircraft Factory (F + W) . It was a medium-decker delta fighter aircraft with jet propulsion and a pressurized cabin in all-metal construction.
| EFW N-20.02 Arbalète | |
|---|---|
 The reduced N-20.02 in the Lucerne Museum of Transport |
|
| Type: | Prototype of a jet fighter |
| Design country: | |
| Manufacturer: | |
| First flight: |
November 16, 1951 |
| Commissioning: |
Development canceled in 1953 |
| Production time: |
Was never mass-produced |
| Number of pieces: |
1 |
history
During the Second World War , engineers in Switzerland began planning jet-powered combat aircraft. The P projects were created, which ultimately led to the P-16 , as well as the N projects, which were developed by the predecessor company of RUAG Aviation in Emmen . There was extensive design work that included the design of the aircraft shape, the engine variants and the engine position. In addition to foreign engines, Swiss in-house developments were taken into account, such as a special form of jet engine in which the main engines deliver bleed air to the auxiliary engines in order to increase their performance. The Swiss Mamba engine was tested in flight by mounting it on the underside of the fuselage of a De Havilland DH.98 Mosquito . The Mosquito had been interned in World War II, was later registered as B-5 and became the property of the Swiss Air Force .
In 1948 the company Gebrüder Sulzer AG built two engines with the designation D45. The non-flightable D45.01 was tested on the test stand from 1950. The conditionally airworthy engine D45.05 was tested until 1955 and achieved a thrust of 752 kp. The Swiss Mamba SM-1 was a modification of F + W Emmen, which was based on the British turboprop engine ASM Mamba 1 from Armstrong Siddeley Motors . Instead of a power turbine for propeller drive, air was fed to the secondary combustion chambers. Six Swiss Mamba were built, four engines were installed in the N-20 and two served as a reserve. a reserve engine is on display today in the Lucerne Museum of Transport. In the case of the N-20 in the Flieger-Flab-Museum in Dübendorf , an engine has been removed for a better view and is exhibited individually.
Since the Swiss industry had no experience with aircraft construction and the aerodynamics of jet planes, a number of wind tunnel models were produced. In addition, a two-seat glider on a scale of 0.6: 1 was built for the planned N-20. The machine had a JATO solid rocket engine, with which it could take off independently and reach the flight altitude required for tests. The nose landing gear came from the de Havilland DH.100 Vampire , the main landing gear from the Messerschmitt Bf 109 and was electromechanically retractable. The cell was built entirely of wood and provided with plywood planking and a fabric cover. However, the plane was destroyed in a landing accident on July 1, 1949.
It was then decided to build another test aircraft on a smaller scale, but this time equipped with four jet engines, one above and below each wing. This aircraft with the designation N-20.2 Arbalète is exhibited today in the Flieger-Flab-Museum .
properties
The N-20 prototype, which was built in its original size, had a detachable bow that, if triggered, was supposed to slide to the ground on a parachute in an emergency. A planned head-up display was not used in the prototype. In order to be able to communicate in the event of radio silence, the N-20 was equipped with signal rockets in the rear.
The aircraft had fold-out canards in front of the wings on the fuselage, which significantly improved the slow flight characteristics . The N-20 had two main engines in the wing profile and four auxiliary engines in each wing. So the plane had four engines and eight afterburners. The exhaust jet could be directed downwards at an angle with the help of flaps in order to shorten the take-off distance. The dimensions of the N-20 correspond roughly to those of the P-16 and were designed in such a way that the aircraft could be operated from an aircraft cavern without any problems .
The Aiguillon had a planned operational speed of 1000 km / h, but the engineers had planned the aircraft for a speed of almost 1200 km / h. With this performance, the Swiss fighter would have been far superior to many other machines of its time.
Various tests showed that the engines would not produce the desired performance. That is why the project N-20.20 Harpon was started. The aircraft corresponded roughly to the N-20, but had a conventional Rolls-Royce Sapphire or Avon engine in the wing root . The wing became a little thinner and the main landing gear came a little closer to the fuselage, as no engines needed any more space in the wing. The N-20.20 was never realized. Only a few wind tunnel models were made.
Termination of development
The N-20 prototype made various tests in the wind tunnel, engine tests, roll tests and a small hop. The project was stopped before the aircraft could take off for its first flight.
Why the East Swiss Federal Councilor Karl Kobelt canceled the project in 1953 and thus around 15 million SFr. put in the sand is not entirely clear. The Federal Council gave the Altenrhein aircraft factory the contract to develop a Swiss fighter aircraft.
Years later, Weltwoche wrote that Emmen was certain that there were too many friendly threads in Eastern Switzerland in Bern.
Many people who worked on the project wanted the plane to take off at least once. They were willing to spend their free time on this and to pay all the costs for this one flight on a private basis. However, the Federal Council refused permission to take off, even though those involved were prepared to take the risks themselves.
Today the N-20 is next to the FFA P-16 in the Aviation and Flab Museum in Dübendorf .
Technical specifications
N-20.1 glider
| Parameter | Data |
|---|---|
| crew | 1 pilot + 1 observer in a separate cockpit in the central fuselage |
| length | 7.53 m |
| span | 7.56 m |
| height | 2.3 m |
| Wing area | 19.1 m² |
| Dimensions | 1400-1580 kg |
| Payload | |
| Engines | 1 × Jato -12 rocket with a burn time of 12 s and 450 kp thrust towing with EFW C-3604 |
| Operating speed | 570 km / h |
| Max. Horizontal speed | 700 km / h (calculated) |
| Minimum speed | 125 km / h |
| Best glide ratio | 15.1 |
N-20.2 Arbalète
| Parameter | Data |
|---|---|
| length | 7.53 m |
| span | 7.56 m |
| height | 2.3 m |
| Preparation mass | 1800 kg |
| Payload | |
| Engines | 4 × Turboméca Piméné with 100 kp static thrust each |
| Operating speed | 570 km / h |
| Max. Horizontal speed | 720 km / h |
| Service ceiling | 8000 m above sea level M. |
| Range | 250 km |
N-20.10 Aiguillon
| Parameter | Data |
|---|---|
| length | 12.6 m |
| span | 12.6 m |
| height | 3.67 m |
| Preparation mass | 6550 kg |
| Payload | 2450 kg |
| Engines | 4 × Swiss Mamba SM-01 each with 6 kN static thrust |
| Operating speed | 1000 km / h (calculated) |
| Max. Horizontal speed | 1200 km / h (calculated) |
| Service ceiling | 11,000 m above sea level M. (calculated) |
| Range | 500 km (calculated) |
| Take-off run at 0 m above sea level M. | 232 m |
| Landing distance to 0 m above sea level. M. | 237 m (calculated) |
Armament
The N-20 was equipped with two permanently installed 20 mm cannons. There was also a gun tub. The weapon tray can be changed in a short time in order to re-ammunition or to convert the aircraft for another purpose.
Four different gun trays were planned:
- one with 4 × 20mm cannons,
- one with 16 bombs weighing 50 kg,
- one with 36 × 87mm missiles,
- one with 24 light bombs, four cameras and 500 liters of fuel.
N-20.20 Harpon
| Parameter | Data |
|---|---|
| length | 12.5 m |
| span | 12.6 m |
| height | 3.67 m |
| Wing area | 62.5 m² |
| Preparation mass | 9470 kg |
| Payload | 2450 kg |
| Engines | 2 × Armstrong Siddeley Sapphire , 33.3 kN each |
| Maximum speed | 1070 km / h (calculated) |
| Minimum speed | 180 km / h (calculated) |
| Rate of climb | 88 m / s (calculated) |
| Service ceiling | 15,500 m above sea level M. (calculated) |
| Range | 1200 km (calculated) |
| Take-off run at 0 m above sea level M. | 420 m (calculated) |
| Landing distance to 0 m above sea level. M. | 550 m (calculated) |
