Slowest jet-powered aircraft
PZL M-15
200 kilometre(s) per hour
Poland ()

The slowest jet aircraft is the Polish-made PZL M-15 "Belphegor", a single-engined crop-dusting plane that made its first flight on 20 May 1973. The Belphegor was a biplane weighed down with two huge pesticide tanks that had a top speed of just 200 km/h (120 mph).

The Belphegor was designed as part of a Soviet program to intensify agricultural production. The USSR's existing crop-dusting aircraft (the Antonov An-2 piston-engined biplane) had relatively limited capacity. It was also a very old (first flown in 1947) and old-fashioned design even then, taking its cues from 1930s utility aircraft. It was hoped that the Belphegor would both improve on the AN-2's crop dusting ability and also serve as a demonstration of the modern Soviet Union's technological sophistication.

The design came out of a mish-mash of contradictory requirements, and was further complicated by the division of work between Polish and Russian teams. What ended up rolling off the production line was the only jet biplane ever to go into production, and also, arguably the ugliest plane ever built.

In practice, the Belphegor proved to be ruinously expensive to both build and operate. It was also challenging to fly for the rural farmer-pilots who had never flown a jet before, and the heat of the jet exhaust caused problems with the distribution of chemicals. In the end the project was abandoned after only 175 had been built, and these airframes were soon mothballed in favour of the near-indestructible An-2 biplane, which is still in use to this day.