Hirth Hi 21
Hirth · Germany · first flew 1944 · glider
The Hirth Hi 21 was a multi-purpose two-seat, side-by-side training glider designed and built in Germany during the Second World War. It had a retractable undercarriage and wings of variable sweep to accommodate centre of gravity changes.
Recognition (WEFT)
| W — Wings | Mid-mounted, variable |
|---|---|
| E — Engines | 1 × none, embedded-mounted |
| F — Fuselage | Retractable undercarriage with a pair of wheels swung up into the fuselage and a fixed tailwheel |
| T — Tail | Conventional |
WEFT is AircraftIQ's four-point recognition method — how it works.
Spot it by:
- Variable-sweep wing, straight tapered with rounded tips
- Two seats side by side ahead of the wing leading edge under a multi-part canopy
- Retractable undercarriage with a pair of wheels swung up into the fuselage and a fixed tailwheel
A conventional cantilever mid-wing glider with a plywood monocoque fuselage and a steel tube framed cockpit area. The straight-edged tailplane sits on top of the fuselage with a small fin at its rear.
Specifications
- The Hirth Hi 21 has a length of 8.22 m (27 ft).
- It has a wingspan of 19.6 m (64 ft).
- Typical crew: 2.
Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.
History
Design work began at the start of 1942 in response to an RLM requirement for a multi-purpose training glider. Variable sweep was chosen to move the aerodynamic centre to the centre of gravity rather than shifting the centre of gravity with movable weights. The Hi 21 first flew on 4 May 1944.
Variants
Only one was completed. Wolfgang Hutter detailed a simplified fixed-monowheel version, and Karl Schewyer and Ferdinand Schmetz designed tandem-seat competition variants, but there is no evidence any of these were completed.
Where you'll see it
On 7 June 1944 an RLM engineer stalled it on landing and severely damaged it, and it did not fly again until after the war. Repaired at the Nabern factory, it was heavily used because few training gliders survived in post-war Germany, and made some 14,000 winch launches in the 18 months to the end of 1946.
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