PZL MD-12

This article covers the Polish MD-12 passenger aircraft; For the project of the same name for the wide-body aircraft from McDonnell Douglas see McDonnell Douglas MD-12 .

PZL MD-12
Second prototype of the MD-12
Type:	Airliner
Design country:	Poland
Manufacturer:	WSK-Okęcie
First flight:	July 21, 1959
Production time:	1959-1962
Number of pieces:	3

The PZL-MD 12 was a Polish airliner for short distances.

history

The MD-12 was developed by Franciszek Misztal and Leszek Dulęba as the successor to the Lisunow Li-2 for the short domestic routes of the LOT . It should be used as a pure passenger or cargo aircraft as well as in a mixed version. The aircraft was originally supposed to be equipped with two Soviet ASch-21 engines. Since their production was discontinued, it was decided to use Polish WN-3 engines. Because these were less powerful, the design was converted to a four-engine machine.

The first prototype with the registration number SP-PAL flew for the first time on July 21, 1959, the second prototype with a fully equipped passenger cabin and the registration number SP-PBD on January 7th, 1961. Another cell was built for static tests. The state approval tests took place in 1961. The second prototype was tested from August to September 1961 on the Warsaw - Rzeszów route and carried over 1700 passengers.

The tests were successful, but there was no series production because it was believed that the production of an aircraft especially for Polish domestic traffic would be uneconomical due to the small number of units. Instead, older machines were used, which had been replaced by more modern ones on international lines.

In addition, a version called the MD-12F was developed as a photo aircraft . She was with u. a. several cameras and a darkroom . This version received a glazed nose in which the navigator also sat. The machine with the registration number SP-PBL flew for the first time on July 21, 1962. The testing of this version was also successful and the Soviet Union , Romania , Hungary and Pakistan showed interest in buying the machine.

MD-12F in the Polish Aviation Museum

On September 17, 1963, the first prototype crashed due to a flutter of the tail unit from where the five-member crew was killed. The project was then terminated.

The MD-12F can be viewed in the Polish Aviation Museum in Krakow .

construction

The PZL MD-12 was a cantilevered all-metal shoulder- wing aircraft . The wings had a slight V-position , the wing trailing edge was swept slightly negative. The fuselage was designed in half-shell construction. The machine had split ailerons and lift flaps. The wings and tail unit were thermally de-iced. The nose wheel landing gear, which was equipped with twin tires, was pulled in hydraulically. The air-cooled seven-cylinder radial engines powered two-bladed propellers.

Technical specifications

Three-sided view of PZL MD-12

Parameter	PZL MD-12
crew	2
Passengers	20th
length	15.80 m
span	21.30 m
height	5.80 m
Wing area	55 m²
Wing extension	8.2
Empty mass	4950 kg
Payload	2550 kg
Takeoff mass	7500 kg
Wing loading	135 kg / m²
drive	four piston engines WN-3
power	4 × 340 PS (250 kW)
Power load	5.45 kg / hp
Top speed	305 km / h
Max. Cruising speed	280 km / h
Rate of climb	5.0 m / s 2.0 m / s with three engines
Service ceiling	5200 m
Cruising altitude	2000 m
Max. Range	700 km
Take-off run	450 m
Take-off distance over 15 m	650 m

literature

• John WR Taylor (Ed.): Jane's All The World's Aircraft - 1965-66 , Sampson Low, Marston & Company Ltd., London, 1965, p. 112 f.

Web links

Commons : PZL MD-12  - collection of pictures, videos and audio files

• PZL MD-12 in the Virtual Aviation Museum

Individual evidence

1. ^ Heinz A. Schmidt: Airplanes from all over the world , Volume 1, Transpress Verlag für das Verkehrwesen 1970
2. ↑ A. F. Schmidt (Ed.): Flieger-Jahrbuch 1962 . Transpress, Berlin 1961, p. 109 .