Glider • Schleicher • ASK 21, ASK 21Mi (retractable gear), ASK 21Mi 18m (extended wingspan)
| Manufacturer | Schleicher |
| Model | ASK 21 |
| Category | Glider |
| Variants | ASK 21, ASK 21Mi (retractable gear), ASK 21Mi 18m (extended wingspan) |
| Production Years | 1979 – 2025 |
| Seating | 1, 2 seats |
| Typical TTAF | 4,200 hours |
| Markets | Germany, United States, United Kingdom, Australia, France |
| Price Range | $45K – $95K |
The Schleicher ASK 21 is a high-performance two-seat training and cross-country sailplane manufactured by Alexander Schleicher GmbH & Co. KG in Germany. First introduced in 1979, it has become one of the most successful and widely-used training gliders globally. The ASK 21 features a single-seat configuration that can be flown solo or converted to two-seat training mode, making it exceptionally versatile for flight schools and clubs. Its construction combines glass-fiber composite materials with excellent aerodynamic design, delivering exceptional climb performance and glide characteristics. The aircraft is renowned for its forgiving handling, stability, and reliability, making it ideal for both student pilots and experienced cross-country soaring pilots. The ASK 21 has achieved remarkable longevity in the market, with thousands produced and continuously operated worldwide. Its proven design has influenced subsequent generations of training gliders. Operators range from gliding clubs and certified flight training organizations to private enthusiasts. The aircraft's ability to perform well in weak thermal conditions and its low operating costs have sustained its popularity for over four decades.
Maximum Speed: 140 knots
Best Glide Ratio: 38:1
Service Ceiling: 28,000 feet
Wing Span: 17.5 meters (standard) / 18 meters (Mi variant)
Empty Weight: 290 kg (standard configuration)
Maximum Takeoff Weight: 520 kg
Construction: Glass-fiber composite
Typical Sink Rate: 0.65 m/s at 40 knots