Schleicher ASK 14

from Wikipedia, the free encyclopedia
Schleicher ASK 14
ASK 14 Motorglider.png
ASK 14
Type: Glider / motor glider
Design country:

Germany Federal RepublicFederal Republic of Germany BR Germany

Manufacturer:

Alexander Schleicher GmbH & Co

First flight:

April 25, 1967

Number of pieces:

62 + 4 licensed buildings

The ASK 14 is a single-seat motor glider with a built-in engine from the Alexander Schleicher company .

history

The ASK 14 was created by Rudolf Kaiser in an effort to construct a self-launching glider that enables real distance gliding despite the additional engine weight. The Ka 6 E, also designed by him, was used as the basis and is considered to be one of the most powerful and technically sophisticated models of the timber construction era. With a glide ratio of 28 and a minimum sink rate of 0.75 m / s, he achieved this goal. Performances like this were not even close to being achieved by the available competitive models such as the RF 3 or the Motorspatz (glide ratio 20 each).

How well the ASK 14 is suitable for gliding is shown by the fact that the engine running time of Kaiser's own ASK 14 was just 2% of the total operating time. Due to these properties, the ASK 14 is still a popular model today, over 50 of the approximately 66 originally manufactured copies still fly today, many even with the original engine.

construction

Because the number of items that could be sold could only be estimated very carefully, the wings had to be closely related to those of the Ka 6 , i.e. have a profile from the NACA 63 series . Since the higher fuselage weight caused by the engine installation would have led to a higher bending load on the wing spar with an unchanged span, the wingspan was reduced from the 15 meters offered on the Ka 6 at that time (earlier versions were only 14.4 m and the very first only 14.0 m) reduced to 14.30 meters. Despite the resulting inevitably reduced aspect ratio, the best possible glide ratio decreased compared to the Ka 6; CR from 30 to just under 28, whereby the increased wing loading probably helped.

As engine was a Hirth -Vierzylinder two-stroke engine selected with 19 kW power, with a 1: 20 petrol-oil mixture is driven. Despite the seemingly low performance, an ASK 14 only needs about 100 m take-off distance.

The fairing of the engine with a half-teardrop-shaped bulge from the rest of the fuselage on the right and left side was obviously aerodynamically successful, which together with the propeller that had to be brought to the sail position limited the basic disadvantage of non-retractable engines for sailing operation.

Compared to modern designs, the pilot of this low-wing aircraft was sitting further back, for example on the nose of the wing. The half-drop-shaped hood gave a good view to the rear, similar to the view from the Hütter H 30 and the resulting dragonfly types from the manufacturer Glasflügel .

use

Based on the key data of the construction, it can be assumed that the ASK 14 with its polar could not be flown harmoniously in formation with the Ka 8 despite the practically identical glide ratio, but could and had to be faster. With the ASK 14, scoring speeds of up to 92 km / h were achieved in the 2010 Glider League, so even teams with much more modern designs such as the ASH 25 Mi and Duo Discus were relegated to the places.

Since a helper was originally always required during take-off to hold the wing during take-off, some ASK 14 were equipped with additional rollers under the wing ends, which enable self-sufficient operation on the ground.

Technical specifications

Parameter Data
crew 1
length 6.65 m
span 14.3 m
height - m
Wing area 12.28 m²
Wing extension 16.2
Glide ratio 28
Slightest sinking 0.75 m / s at 72 km / h
payload 115 kg
Empty mass 245 kg
Takeoff mass 360 kg
Cruising speed
Top speed 200 km / h
Service ceiling - m
Range - km
Engine a Hirth F10 A1a, 25 hp

See also

literature

  • Peter F. Seliger: Rhön-Adler. 75 years of Alexander Schleicher glider construction. Publisher RG Fischer, Frankfurt a. M. 2003.
  • Richard and Monique Ferrière: Les Planeurs et Motoplaneurs d 'Alexander Schleicher 1951–1981. Motorbuch-Verlag, Stuttgart 1988, ISBN 3-613-01190-5 .

Web links

Commons : ASK 14  - collection of images, videos and audio files

Individual evidence

  1. ↑ Alexander Schleicher: All types of aircraft since 1951 , accessed on December 18, 2018.