Schleicher ASW 24

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**Schleicher ASW 24**
ASW 24 sailplane, competition number '96' owned by Imperial College Gliding Club
Type designation	ASW 24
Competition class	Standard
Number built	249
Crew	1
Length	6.55 m
Height	1.3 m
Cockpit width	0.64 m
Cockpit height	0.81 m
Wingspan	15 m
Wing area	10.00 m²
Aspect ratio	22.5
Wing profile	DU 84-158
Empty mass	ca. 230 kg
Water ballast	155 kg (ASW 24) 160 kg (ASW 24B)
Tail water ballast	unavailable
Maximum mass	500 kg
Wing loading	ca. 31.0 - 50.0 kg/m²
Minimum sink rate	ca. 0.55 m/s at 31 kg/m²
Best glide ratio	ca. 43 (ASW 24) ca. 44 (ASW 24B)

The ASW 24 is a modern single seat high performance composite Standard Class sailplane.

[edit] History

The ASW 24 was designed by Schleicher's Gerhard Waibel, with Delft University professor Loek Boermans undertaking the role of aerodynamicist. The prototype made its first flight in 1987, having entered serial production later the same year. It nominally remained in production until 2000, although only a score were built in the mid-to-late nineties.

It entailed a large development effort, as it was a complete departure from the preceding ASW 19 and pioneered several successful innovations. The fuselage, airfoils, wings and empennage were completely new, as well as many systems, e.g. the electrical ballast management. The structure employed a large amount of the then still exotic carbon fibre. The OSTIV Award-winning safety cockpit made use of an organic shape, tall sidewalls, crumple zones and exotic aramid fibres for crash protection. A large wheel with a disc brake and a large canopy with excellent visibility were other strong points of the type.

The ASW 24 was moderately successful in competitions. It won a single World Championship in 2001, fourteen years after its market launch. As the contemporary LS7, the ASW 24 overstretched the technology available at the time: it has excellent performance in the cruise but less so in the slow flight range. The higher-than-usual thermalling speed revealed itself a disadvantage in the typical competition gaggles, and its performance degrades somewhat when subject to turbulence, rain or wing contamination. However, the addition of winglets and a change to the outer wing leading edge, making it slightly blunter, improved these characteristics significantly.

According to World Champion Sarah Steinberg, it needs to be always proactively flown in thermals, thus imposing a higher workload upon the pilot. Notwithstanding, the aesthetically pleasing ASW 24 is a comfortable, safe and pleasant sailplane with high cross-country performance that remains competitive up to national championship level in most countries.

The fuselage of the ASW 24 was the basis, with small modifications, for the subsequent ASW 27, ASW 28 and ASG 29. It was superseded in production by the ASW 28.

[edit] Variants

The ASW 24B of 1993 introduced winglets and a slightly revised airfoil that were partially successful in addressing the handling and performance issues.

The ASW 24E is a nominally self-launching variant employing a Rotax 275 engine and a propeller mounted on a retractable pylon. The engine installation is peculiar for its small size and power, more typical of a turbo, and for its manual start with a pilot-operated ripcord.

**Schleicher ASW 24E**
Number built	54
Empty mass	ca. 275 kg
Engine type	Rotax 275 1 cylinder 2-stroke
Engine power
Fuel tank capacity
Climb rate in powered flight
Range in 'saw-tooth' operation