It was created as a modification of the 4-seat, multi-purpose Soviet aircraft Yak-12M, produced at WSK-Okecie, in response to the demand for agricultural and forestry aviation services.
The modifications to the design consisted of installing a 550-litre chemical tank in place of the rear seats, introducing a 4-degree wing sweep, adding wingtip plates, moving the main undercarriage rearward, enlarging the horizontal stabiliser, and changing its angle of incidence. The prototype was first flown on 14 April 1958, and serial production began in 1960. By 1970, when production ended, 326 examples were built, including 215 agricultural, 79 executive, and 32 ambulance versions. Of these, 134 examples were exported, mainly the agricultural version.
The aircraft proved itself in service and created the equipment conditions for the development of agricultural aviation in Poland and the growth of agro-aviation services abroad. From 1967, PZL-101 agricultural aircraft operated in Poland were sent to Egypt and Sudan, and from 1976 they were replaced by the safer and more efficient specialised PZL-106 Kruk aircraft. Their operation there ended in 1983. To this day, PZL-101 aircraft are still used domestically in the aero club version.
The “Gawron” (Rook) is a single-engine strut-braced high-wing monoplane of metal construction, covered with fabric. The fuselage is welded from steel tubes. The undercarriage is fixed with a tailwheel, shock-absorbed by rubber bungee cords. The wing is a two-spar duralumin structure with a fixed slot. Fuel tanks of 80 litres each are located in the wings. Additional 90-litre tanks can be mounted under the wings for ferry flights. The powerplant is a radial AI-14R engine rated at 260 hp (191 kW), produced at WSK-Kalisz, and a variable-pitch wooden propeller W530D, manufactured at WSK-Okecie.
The agricultural equipment was mounted to the tank throat. The dry fertiliser version had an open tunnel and a stirrer in the tank driven by a windmill mounted above the tank. Chemicals were loaded through a hatch above the tank. The spraying version had a pumping unit with a centrifugal pump driven by a windmill, control valves, and pipes with nozzles mounted on the struts and wing. The liquid spraying apparatus had an emergency dump system for liquids from the tank. The agricultural equipment was controlled by a pneumatic system.
| Wingspan | 12.68 m |
| Length | 9.0 m |
| Takeoff weight | 1660 kg |
| Maximum speed | 170 km/h |
| Ceiling | 2400 m |
| Range | 450/1100 km |
| Armament | – |
| Engine | 9-cylinder radial air-cooled PZL AI-14R, 260 hp (191 kW) |
