PZL MD-12
The PZL- MD 12 was a Polish airliner for short trips.
History
The MD -12 was developed as a successor to the Lisunow Li -2 for the domestic short-haul LOT. It should be used exclusively as passenger or cargo plane and a combined version. The aircraft was originally to be equipped with two Soviet ASch -21 engines. Since production has been stopped, it was decided for Polish WN - 3 engines. Because these were less powerful, the design was changed to a four -engine aircraft.
The first prototype with the identifier SP PAL first flew on July 21, 1959, the second prototype with a fully equipped passenger cabin and the identifier SP -PBD on January 7, 1961. Another cell was built for static tests. The state licensing tests were performed in 1961. The second prototype was tested from August to September 1961 the Warsaw- Rszeszow and carried more than 1,700 passengers.
Although the tests were successful. However, there was no mass production, because it was believed that the production of an aircraft would be especially uneconomical for the Polish domestic traffic because of the small number of items. Instead, older machines were used that had been displaced on the international lines by more modern.
In addition, a designated as MD - 12F version was developed as a photo plane. She was with, inter alia, multiple cameras and a darkroom equipped. This version was given a glazed nose cones in the sitting and the Navigator. The machine with the registration SP- PBL first flew on 21 July 1962. The testing of this version was successful and the Soviet Union, Romania, Hungary and Pakistan have shown interest in buying the machine.
On September 17, 1963, the first prototype crashed due to a flutter of the tail, where the five -member crew was killed. Subsequently, the project was terminated.
The MD - 12F can be seen in the Polish Aviation Museum in Krakow.
Construction
The PZL MD -12 was a cantilever all-metal high-wing monoplane. The wings had a slight dihedral, the wing trailing edge was slightly negative swept. The hull was carried out in semi- monocoque construction. The machine had split ailerons and lift flaps. Wings and tail were thermally de-iced. The equipped each with twin wheels tricycle landing gear was retracted hydraulically. The air-cooled seven-cylinder radial engines drove to two-blade propellers.