PZL MD-12

Le quadrimoteur PZL MD 12 par Wikipedia de langue anglaise

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The [Vous devez être inscrit et connecté pour voir ce lien] MD-12 was a [Vous devez être inscrit et connecté pour voir ce lien] four-engined short-range passenger and civil utility aircraft of the 1960s, which remained in a prototype stage.

Design and development

The aircraft was development as a successor to the [Vous devez être inscrit et connecté pour voir ce lien] on short domestic routes for [Vous devez être inscrit et connecté pour voir ce lien].

The plane was designed by a design bureau led by [Vous devez être inscrit et connecté pour voir ce lien] in the Aviation Institute (Instytut Lotnictwa).

The first design work started in 1954 (under the designation FM-12) and the final design MD-12 appeared in 1956, after Leszek Dulęba had joined (the designation apparently came from Misztal-Dulęba).

Initially it was to be powered with two Soviet 615 hp ASh-21 engines, but because their production stopped, a four-engine configuration was chosen, with Polish 315 hp WN-3 engines.

In December [Vous devez être inscrit et connecté pour voir ce lien] the bureau was moved to the OKL centre (Ośrodek Konstrukcji Lotniczych - Aviation Designs' Centre), created in the [Vous devez être inscrit et connecté pour voir ce lien] factory.

The first prototype flew first on 21 July 1959 (registration SP-PAL), the second prototype, designated MD-12P (SP-PBD), and fitted with complete passenger cab, on 7 January 1961.

There was a third airframe built for static trials.

The plane underwent state trials in 1961, and the second prototype was evaluated by LOT Airlines in August-September 1961.

The passenger variant was evaluated as quite successful, being easier to fly, than the [Vous devez être inscrit et connecté pour voir ce lien] and more economical, but it was not produced because LOT found it unprofitable to order special planes for domestic routes.

The small production that would result would increase costs. Instead, less modern airliners were switched from international to domestic routes.

It was next decided to build an [Vous devez être inscrit et connecté pour voir ce lien] variant MD-12F.

It was fitted with several cameras and other equipment, including a darkroom.


The fuselage nose was glazed, with a navigator post. Span increased to 23.6 m by adding longer wingtips.

The MD-12F flew first on 21 July 1962 (apparently dates of MD-12 prototypes' flights were adjusted to add splendour to communist Poland's national holiday, 22 July).

It carried the registration SP-PBL.

The aerial photography variant was successful and countries, like the USSR, Hungary, Romania and Pakistan were interested in it, but its development was ceased along with a crash of the first MD-12 prototype on 17 September 1963 near [Vous devez être inscrit et connecté pour voir ce lien].

The plane crashed due to [Vous devez être inscrit et connecté pour voir ce lien] of tail control surfaces and a crew of 5 were killed.

Operational service

The prototype MD-12P (SP-PBD) was evaluated by the [Vous devez être inscrit et connecté pour voir ce lien] in August-September 1961, on Warsaw-[Vous devez être inscrit et connecté pour voir ce lien] route, carrying over 1700 persons.

It was also used in 1961 and 1962 on Warsaw-[Vous devez être inscrit et connecté pour voir ce lien] route, taking trips to [Vous devez être inscrit et connecté pour voir ce lien]. Design

The MD-12 was a four-engined low-wing cantilever [Vous devez être inscrit et connecté pour voir ce lien] of all-metal construction, [Vous devez être inscrit et connecté pour voir ce lien]-covered.

The fuselage was a semi-[Vous devez être inscrit et connecté pour voir ce lien]. The crew cockpit in front with a crew of two pilots.

Passenger cab with 20 seats in three rows.

In the rear there was WC. Fuselage had doors in front part.

In a fuselage nose there was a baggage space for 200 kg.

Trapezoid three-part wing. Single tailfin. Engine nacelles in wings.

Two-blade wooden propellers WR-1A of a variable pitch, diameter 2.2 m (powerplants were adapted from the [Vous devez être inscrit et connecté pour voir ce lien] trainer).

Retractable [Vous devez être inscrit et connecté pour voir ce lien] - main gear with single wheels retractable to inner engine nacelles.

Fuel tanks 1160 l in wings (cruise fuel consumption 240 l/h).

Variants

MD-12

Prototype. One built, registered as SP-PAL.

MD-12P

Passenger version. One built, registered as SP-PBD.

MD-12F

Aerial photography version with glazed nose and increased wing span. One built, registered as SP-PBL.

MD 12F

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