Schleicher ASK 13

{{Short description|German two-seat glider aircraft, 1966}} {{More citations needed|date=January 2023}}  {{Infobox aircraft | name=ASK 13 | image=PH-521 Schleicher ASK-13.JPG | caption= | type=Sailplane | national_origin=Germany | manufacturer=[[Alexander Schleicher GmbH & Co|Schleicher]] | designer=[[Rudolf Kaiser]] | first_flight=July 1966 | introduction= | retired= | status= | primary_user= | number_built=700+ | developed_from= | variants= }} [[File:Instrument panel of Schleicher ASK 13.jpg|thumb|[[Flight instruments|Instrument panel]] of ASK 13]] The '''ASK 13''' is a two-seater [[Glider (sailplane)|glider]] that was built by German sailplane manufacturer [[Alexander Schleicher GmbH & Co|Alexander Schleicher Gmbh & Co]]. It was and still is widely used for basic training of [[gliding|glider pilots]].

== Design and development == In 1965 [[Rudolf Kaiser]] continued development of the two-seat Ka 2 and [[Schleicher Ka 7]] by introducing the ASK 13, using a mixture of materials including metal, wood and [[Fiberglass|fibreglass]]. It has swept-forward single-spar wings, positioned lower than in the Ka 7, which allows for a large blown canopy providing a good all-round view for both pilots.

The 6 degree [[Forward-swept wing|forward sweep of the wing]] allows the rear pilot to be seated near the [[Center of gravity of an aircraft|centres of gravity]] and [[Center of pressure (fluid mechanics)|lift]]. The glider therefore maintains the same trim whether flown single seated or dual seated. The D-type leading edge torsion box is of [[plywood]] and the whole wing is [[fabric]]-covered. There are metal Schempp-Hirth air brakes above and below the wing, and the wooden [[ailerons]] are fabric-covered. The fuselage is a welded steel tube structure with spruce stringers and fabric-covered overall, except for the nose, which is fibreglass. The tail unit is plywood-covered, except for the rear part of the rudder and elevators, which are fabric-covered, and there is a trim tab in the starboard elevator.<ref>{{Cite web |last=Alexander Schleicher GmbH |title=ASK 31 Flight Manual |url=https://members.gliding.co.uk/wp-content/uploads/sites/3/2024/10/ASK13_Flight_Manual-1.pdf |access-date=2025-01-12 |website=gliding.co.uk}}</ref>

Landing gear consists of a non-retractable sprung wheel, mounted aft of the centre of gravity. The original design featured a skid under the nose and tail, although on many K13s these have been replaced with wheels to make handling on hard surfaces easier.

It first flew in prototype form in July 1966 and by January 1978 a total of approximately 700 ASK 13s had been built by Schleicher. They are superb training gliders because they stall and spin well but these manoeuvres are easy to recover from. Their construction also gives them great strength and yet they are easily repairable.

The aircraft was succeeded by the [[Alexander Schleicher ASK 21|ASK 21]].

{{Aircraft specs |ref=Flight manual |prime units?=met  |crew=2 |length m=8.18 |span m=16 |height m=1.6 |wing area sqm=17.5 |aspect ratio=14.6:1 |airfoil=Gö 535/Gö 549 |empty weight kg=295 |max takeoff weight kg=480 |more general=  |stall speed kmh=57 |never exceed speed kmh=200 |never exceed speed note=in smooth air ::::{{convert|140|kph|kn|abbr=on}} in rough air ::::{{convert|140|kph|kn|abbr=on}} on aero-tow ::::{{convert|120|kph|kn|abbr=on}} on winch launch (58kn with Tost black cable weak link) |g limits=+4.0 -2.0 at {{convert|140|kph|kn|abbr=on}} |glide ratio=27 at {{convert|85|kph|kn|abbr=on}} |sink rate ms=0.80 |sink rate note= at {{convert|68|kph|kn|abbr=on}} |lift to drag= |wing loading kg/m2=27.7 |more performance= |avionics= }}

==See also== {{aircontent  |see also= |related= |similar aircraft= *[[PZL Bielsko SZD-9]] *[[LET L-13 Blaník]] *[[CVT M-200]] *[[Scheibe Bergfalke]] |lists= *[[List of gliders]] }}

==References== {{Commons category}} {{reflist}} *[https://www.alexander-schleicher.de/ Schleicher Web Site] *[http://www.sailplanedirectory.com/ Sailplane Directory]

[[Category:Schleicher aircraft]] [[Category:1960s German sailplanes]] [[Category:Forward-swept-wing aircraft]] [[Category:Mid-wing aircraft]] [[Category:Aircraft first flown in 1966]]