PZL M-4 Tarpan (also tarpan) was a Polish trainer and sports aircraft prototype of the 1960s, designed in

WSK-Mielec PZL Mielec (''Polskie Zakłady Lotnicze'' - Polish Aviation Works), formerly WSK-Mielec (''Wytwórnia Sprzętu Komunikacyjnego'') and WSK "PZL-Mielec" is a Polish aerospace manufacturer based in Mielec. It is the largest aerospace manufacturer i ...

Design and development

The M-4 was designed for a demand of the

Polish Aero Club Aeroklub Polski (AP; ''Polish Aero Club'') is the Polish central association of persons practising air sports or recreational flying. It was founded in 1921 and is a member of the Fédération Aéronautique Internationale. It has a headquarters in ...

, for a trainer plane with a retractable

tricycle landing gear Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle g ...

. It was based on an earlier project PZL M-2. The basic variant was to be M-4P, for

navigation Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation, ...

training. The works started in 1958, and the first prototype was built in

1960 It is also known as the "Year of Africa" because of major events—particularly the independence of seventeen African nations—that focused global attention on the continent and intensified feelings of Pan-Africanism. Events January * Ja ...

. Due to a long engine development, it first flew on September 7, 1961 (registration SP-PAW). Trials showed, that the weight was much higher, than estimated (890 kg instead of 748 kg), which demanded changes in design. In July

1964 Events January * January 1 – The Federation of Rhodesia and Nyasaland is dissolved. * January 5 - In the first meeting between leaders of the Roman Catholic and Orthodox churches since the fifteenth century, Pope Paul VI and Patriarch ...

the second prototype was flown (registration SP-PAK). The flight characteristics and stability of the M-4 were estimated as good, it was also fit to

aerobatics Aerobatics is the practice of flying maneuvers involving aircraft attitudes that are not used in conventional passenger-carrying flights. The term is a portmanteau of "aerial" and "acrobatics". Aerobatics are performed in aeroplanes and glid ...

and rally flying. The cab offered an excellent view for the crew and the plane was overall quite successful. However, because of too high price, the Polish Aero Club decided not to order the plane and the production has not started. A development of the flat engine PZL WN-6 was troublesome and was finally canceled at that time as well.

Description

Metal construction low-wing

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

, conventional in layout, metal covered. Semi-

monocoque Monocoque ( ), also called structural skin, is a structural system in which loads are supported by an object's external skin, in a manner similar to an egg shell. The word ''monocoque'' is a French term for "single shell". First used for boats, ...

fuselage.

Trapezoid A quadrilateral with at least one pair of parallel sides is called a trapezoid () in American and Canadian English. In British and other forms of English, it is called a trapezium (). A trapezoid is necessarily a Convex polygon, convex quadri ...

two-spar wings. Crew of two, sitting in

tandem Tandem, or in tandem, is an arrangement in which a team of machines, animals or people are lined up one behind another, all facing in the same direction. The original use of the term in English was in ''tandem harness'', which is used for two ...

, under a common

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an a ...

, with double controls (student in front, instructor in the rear). Retractable

. Two-blade wooden propeller of variable pitch (diameter 2 m). Fuel tanks in wings (140 L).

Operational history

1965 Events January–February * January 14 – The Prime Minister of Northern Ireland and the Taoiseach of the Republic of Ireland meet for the first time in 43 years. * January 20 ** Lyndon B. Johnson is Second inauguration of Lyndo ...

both prototypes were converted to single seater aerobatics variant (in some sources known as the M-4A) by removing front cab equipment. It was planned to use them in World Aerobatics Championship in 1966 in Moscow, but they have not finished full homologation trials and the idea was abandoned. They were not used in this role much.

Operators

; *''

Aeroklub Polski Aeroklub Polski (AP; ''Polish Aero Club'') is the Polish central association of persons practising air sports or recreational flying. It was founded in 1921 and is a member of the Fédération Aéronautique Internationale. It has a headquarters in ...

'' operated second prototype in

Mielec Mielec ( yi, מעליץ-Melitz) is the largest city and seat of Mielec County. Mielec is located in south-eastern Poland (Lesser Poland), in the Subcarpathian Voivodeship (Województwo Podkarpackie). The population of Mielec in December 2021 was ...

Survivors

The second M-4 prototype (SP-PAK) is preserved in the

Polish Aviation Museum The Polish Aviation Museum ( pl, Muzeum Lotnictwa Polskiego w Krakowie) is a large museum of historic aircraft and aircraft engines in Kraków, Poland. It is located at the site of the no-longer functional Kraków-Rakowice-Czyżyny Air ...

Kraków Kraków (), or Cracow, is the second-largest and one of the oldest cities in Poland. Situated on the Vistula River in Lesser Poland Voivodeship, the city dates back to the seventh century. Kraków was the official capital of Poland until 1596 ...

, from 1971.

Specifications

References

*Janusz Babiejczuk, Jerzy Grzegorzewski: ''Polski przemysł lotniczy 1945-1973'', Warsaw 1973 (Polish language) *Marian Krzyżan: ''Samoloty w muzeach polskich'', WKiŁ, Warsaw 1983, (Polish language) * {{PZL aircraft 1960s Polish civil trainer aircraft 1960s Polish sport aircraft M04 Low-wing aircraft Single-engined tractor aircraft Aircraft first flown in 1961