PZL Bielsko SZD-21 Kobuz

infobox Aircraft
name = SZD-21-2b Kobuz 3
type = aerobatic glider

manufacturer = Szybowcowy Zaklad Doswiadczalny


caption =
designer = Trzeciak
first flight = 1964 (prototype in summer of 1961)
introduction =
retired =
status =
produced = 1964-1981
number built = unknown
program cost=
unit cost =
developed from =
variants with their own articles =

The SZD 21 "Kobuz" was a single seat aerobatic glider manufactured by Szybowcowy Zaklad Doswiadczalny.

Design and development

Development of the SZD-21 started in 1958, with the first prototype flying on 3 June 1961. The flight characteristics were however disappointing, so the glider was largely redesigned. The second prototype then flew in the spring of 1962. This prototype crashed as a result of a flutter test which killed the pilot. The flight characteristics were still not satisfactory, so a third type was built, the Kobuz 3. This glider was first flown on 10 December 1964, and was thereafter built in small numbers.

The aircraft resembled the SZD-24 Foka, which also had a significant amount of wooden construction.

pecifications (Kobuz)

aerospecs
ref= [Hardy 1982, p.126.]
met or eng?=met

crew=1
capacity=
length m=7.22
length ft=23
length in=7.5
span m=14
span ft=45
span in=11.5
height m=1.9
height ft=6
height in=3
wing area sqm=13.50
wing area sqft=145.3
gross weight kg=445
gross weight lb=981

max speed kmh=350
max speed mph=217
cruise speed kmh=
cruise speed mph=
range km=
range miles=
endurance h=
endurance min=
ceiling m=
ceiling ft=
glide ratio=27.8 (at 97.2km/h)
climb rate ms=
climb rate ftmin=
sink rate ms=0.99 (at 86.5km/h)
sink rate ftmin=

*Wing Airfoil: NACA 641412

*Manoeuver Speed Va: 188 km/h
*Max Lift/Drag Ratio: 27.8 97.2 km/h
*Load Factors: +7 g / -5 g

ee also

aircontent
see also=
related=
* Swift S-1
* MDM-1 Fox
* PZL Bielsko SZD-59
similar aircraft=
sequence=
lists=
* List of gliders

References

* Hardy, Michael. "Gliders and sailplanes of the World". London: Ian Allen, 1982. ISBN 0-7110-1152-4.

External links

* [http://www.sagach.ch/Deutsch/Flugzeuge/Kobuz.htm SZD-21-2b Kobuz 3 (Lerchenfalke)] by SAGA