PZL M-15 Belphagor
The PZL M-15 was a jet-powered sesquiplane designed and manufactured by the Polish aircraft company WSK PZL-Mielec for agricultural aviation. In reference to both its strange looks and relatively loud jet engine, the aircraft was nicknamed Belphegor, after the noisy demon.
Development of the M-15 can be traced back to a Soviet requirement for a modern agricultural aircraft to succeed the Antonov An-2; it was at the insistence of Soviet officials that jet propulsion would power the type. WSK Mielec's design team recognised the value of the An-2's biplane configuration to the role and set about developing an initial experimental aircraft, the Lala-1, for Latające Laboratorium 1 ("Flying Laboratory 1") to explore the use of a jet engine with such a configuration. On 20 May 1973, the first M-15 prototype performed its maiden flight; even during the test flight phase, it was apparent that there were several drawbacks to the aircraft, including its poor handling, limited range, and high operating costs. While production commenced in 1976, these problems remained unresolved and meant that the M-15 was noticeably inferior in several respects to the An-2. During 1981, production was terminated in favour of procuring more An-2s; a total of 175 M-15s were built against the many thousands which had once been planned.