Akaflieg Karlsruhe AK-1
| Akaflieg Karlsruhe AK-1 | |
|---|---|
.jpg) AK-1 in the Schleissheim aircraft yard of the Deutsches Museum |
|
| Type: | Glider with retractable engine |
| Design country: | |
| Manufacturer: | |
| First flight: |
January 9, 1971 |
| Number of pieces: |
1 |
The Akaflieg Karlsruhe AK-1 is the first major project of Akaflieg Karlsruhe after the re-establishment in 1951, a self-launching motor glider with a retractable engine. After the designer Otto Funk and co-founder of FK Leichtflugzeuge , the aircraft is also known as the FK-4 .
Objectives of the project
The aim of the AK-1 project was a self-launching, weather-resistant glider of the standard class . Self-launch should be possible without an additional person and the aircraft should require minimal maintenance and overhaul. Since the engine should have little effect on the performance of the aircraft, it was planned to be foldable. The Hirth F10 drive train served as the basis.
construction
In terms of construction, Akaflieg wanted to break new ground in aircraft construction, so a decision was made in favor of a metal / GRP composite construction, as the still young GRP construction was not very widespread. The newly developed metal adhesive technology also appeared to be very promising, since annoying rivets could be dispensed with.
Wing and tail unit
A U-shaped spar was used in the wing , which was created by gluing and riveting web plates for the upper and lower chords with reinforcement straps and fittings. Then flanging ribs were attached, which gave the shape. With the exception of the rudder, all control surfaces were manufactured on the same principle as the wing. In order to prevent vibration problems that would have been generated by the propeller jet, a cross tail was used instead of a T-tail. The rudder was with cables, the remaining rudders are controlled by rods.
Hull and engine
The fuselage consists of a tubular steel framework, which is clad with a GRP shell. This design offered enough space for the control and the drive unit with its complex retraction and extension kinematics.
A 4-cylinder two-stroke Hirth F10A engine was used as the drive, with 28 HP and a compressed air screw 1.3 meters in diameter delivering the necessary thrust. To avoid cooling problems, the engine was extended together with the propeller. The retraction and extension was controlled mechanically by the pilot, who was supported by 12 elastic bands.
Use and whereabouts
The first flight of the AK-1 was in January 1971. After many years in the Akaflieg Karlsruhe, the aircraft has been on display since October 18, 2008 in the Schleissheim aircraft yard of the Deutsches Museum.
Technical specifications
| Parameter | Data |
|---|---|
| crew | 1 |
| length | 7.20 m |
| span | 15 m |
| height | |
| Wing area | 14.36 m² |
| Wing extension | 15.7 |
| Glide ratio | 30th |
| Slightest sinking | |
| Preparation mass | 323.8 kg |
| Max. Takeoff mass | 420 kg |
| Top speed | 180 km / h |
| Engines | 1 × four-cylinder two-stroke engine Hirth F10A, 26 PS (19 kW) at 5000 rpm |
| propeller | HO 02-130B85D |
Web links
Individual evidence
- ↑ a b c d AK-1 "Mischl". Akaflieg Karlsruhe, June 11, 2015, accessed on February 28, 2017 .
- ^ Dietmar Geistmann: Gliders in Germany . 2nd Edition. Motorbuch Verlag, Stuttgart 1994, ISBN 3-613-01449-1 , p. 59 .
- ^ Akaflieg Karlsruhe AK-1. In: deutsches-museum.de. Deutsches Museum, accessed on February 28, 2017 .
