The IS-3 “ABC” was the first single-seat training glider designed and produced in Poland after World War II, created by engineers Rudolf Matz and Roman Zatwarnicki at the Gliding Institute in Bielsko. This simple, inexpensive, safe and easy-to-fly glider, modelled on the pre-war Polish gliders Wrona and Żaba and the German SG-38, was intended for mass initial training (up to categories A and B). It was adapted for winch launches.
The prototype was first flown in December 1947 by pilot Piotr Mynarski, and as early as September 1948 the first production aircraft made its maiden flight. As a result of several years of operational experience, three production versions were developed: “ABC-bis” — with folding wings and tail surfaces, “ABC-ter” — with non-folding wings and tail surfaces, and the “ABC-A” developed in 1955 — with wings of lower dihedral angle and a greater aileron deflection range.
The “ABC” gliders could be fitted with a lightweight canopy designed specifically for them. Over 250 units were produced in total, including 125 “ABC-A” variants, some of which were exported to China. The “ABC” gliders were phased out of aeroclub training by the late 1950s, primarily due to the transition to training on dual-control gliders.
The glider displayed at the Museum is an IS-3 “ABC-A”, serial number 270, registration SP-1697, manufactured in 1957. It was operated by the Tatra Aeroclub in Nowy Targ. It was donated to the Museum collection on 26 November 1964.
| Wingspan | 9 m |
| Length | 6.3 m |
| Wing area | 13.5 m2 |
| Empty weight | 105 kg |
| Takeoff weight | 185 kg |
| Glide ratio | 9.2 at optimal speed of 53 km/h |
| Sink rate | min. 1.5 m/s at economy speed of 48 km/h |
| Minimum speed | 45 km/h |
| Max. dive speed | 135 km/h |
