PZL M-15 Belphegor

A serious contender for the title of the world’s ugliest aircraft is the PZL M-15 Belphegor.  It was the result of a Soviet specification for an agricultural aircraft with a requirement for jet propulsion.  The “low and slow” crop dusting mission profile conflicting with the typical operating parameters for jet propulsion produced several design compromises.

Poland was the main producer of agricultural aircraft for the Soviet bloc, so the design work fell to WSK PZL-Mielec.  The engine dictated for use to the design team was the Ivchenko-Progress AI-25, the same engine which powered the L-39 Albatros jet trainer.  To test the engine under low-speed low-altitude conditions an An-2 was modified with a new lattice rear fuselage, redesigned tail surfaces, and a large intake on the starboard side of the fuselage producing yet another uniquely unattractive aircraft.

The aircraft is named after the demon Belphegor, likely due to the design’s lack of aesthetics.  Here is video of the M-15 in flight:  https://video.search.yahoo.com/yhs/search;_ylt=AwrCxGGzVplcYE8A61QPxQt.;_ylu=X3oDMTB0N2Noc21lBGNvbG8DYmYxBHBvcwMxBHZ0aWQDBHNlYwNwaXZz?p=PZL+M-15+Belphegor&type=sbc_dsl&hspart=att&hsimp=yhs-att_001&ei=UTF-8&fr=yhs-att-att_001#id=8&vid=cc8d1a0e6470b2637ebe7ef75e485d7a&action=view

Series production ran from 1976 through 1981.  3,000 were ordered but only 175 were built due to disappointing performance.  None are believed to be flightworthy today although several are preserved in museums.

Two large tanks for chemicals were positioned between the wings which carried a respectable total capacity of 750 gallons (2,900 liters).  The aircraft could be configured with various spray systems to optimize the distribution of the specific chemicals.  Provision was made for two technicians to be carried in the fuselage to operate the spray systems if necessary.

Performance was adequate for an agricultural aircraft, was but shockingly slow for a jet.  Maximum speed was only 124 mph, cruising speed was in the 90 – 100 mph range.  Payload was an impressive 6,000 pounds.

The Belphegor could lay claim to some unique niches in aviation history.  It was the only production jet biplane, it was the only jet crop duster, and it was the world’s slowest jet aircraft.