Let
Let / Zlin Z-37 Bumble Bee
 Photo: Robert Deering 4/9/2019
 Technik Museum
 Speyer, Germany

Z-37 Bumblebee

The Zlin Z-37 Čmelák (Czech: "Bumblebee"), also known as LET Z-37 Čmelák, is an agricultural aircraft which was manufactured in Czechoslovakia. It is powered by a Soviet-built Ivchenko reciprocating engine. The aircraft is used mainly as a cropduster.

Design work on the first purpose-designed agricultural aircraft started in Czechoslovakia in 1961, with a cooperation of two manufacturers: Let Kunovice and Moravan (Zlin brand). The first prototype, designated as XZ-37, first flew on 29 March 1963 (other sources:29 June). It was a cantilever low-wing monoplane of tubular metal construction, the wings and stabilizers covered with duralumin and the fuselage and control surfaces made of fabric. It had a fixed undercarriage with a fully castering tail wheel, but locked to the rudders for ground handling. The pilot's cockpit was in front, immediately behind a 315 hp radial engine, with a hopper for chemicals situated behind the cockpit. This offered the pilot a good view, but was potentially dangerous in case of an emergency landing. A mechanic could be seated behind the hopper, facing backwards. There were also spray booms mounted under the wings. There is also a freight version with open space instead of hopper and spray equipment and a -3 variant with three passenger seats facing rearwards.

The aircraft was produced from 1965 under the designation Z-37. From 1971, the Z-37A was produced, with a strengthened construction. It was produced until 1975, and then in 1983-1984. 677 were produced, including 27 two-seater Z-37A-2s for crew training.

On 6 September 1981 the prototype XZ-37T first flew, powered by a (691 shp) Walter M-601B turboprop engine. Two further prototypes of the definitive turboprop version, the Z-37T Agro Turbo, powered by a less powerful M-601Z engine, flew on 12 July and 29 December 1983. As well as the new engine, it had longer-span wings (13.63 m) fitted with winglets.

The Z-37T was produced from 1985 until 1994, with a total of 51 aircraft built, including some Z-37T-2 two-seater trainers. Later production aircraft were redesignated Zlin Z-137T.

SOURCE: Wikipedia

Let Aircraft

Aircraft Industries, a.s., operating as LET, n.p., is a Czech (formerly Czechoslovak) civil aircraft manufacturer. Its most successful design has been the L-410 Turbolet, of which more than 1200 units have been built. Its head office is in Kunovice, Uherské Hradiště District. LET is since 2008 owned by Russian company UGMK. The company operates the sixth largest Czech airport and a private secondary school.

Building of an aircraft factory in Kunovice started in 1936, as a part of the Škoda Works industrial concern. Before and during World War II the unfinished plant served only as a repair works. After the end of the war the factory was nationalized and in 1950-53 a new plant was built. In 1957-1967 it was named SPP (Strojírny první pětiletky - "Works of the First Five-year Plan"), and in 1967 it returned to the name LET. The works produced under licence were the Soviet trainers Yakovlev Yak-11 (under a designation C-11) and the Aero Ae 45 and Aero Ae 145 utility aircraft.

In 1957 the company began to develop the L-200 Morava light utility aircraft and four years later the Z-37 Cmelak agricultural aircraft, which were both a commercial success. For a period of time LET also produced a jet training aircraft the L-29.

Over the years LET developed and produced gliders–Zlín Z 22, Z 124 Galánka, LF 109 Pioneer, Z 425 Šohaj. However the most popular gliders produced by LET are the Blaníks–L-13 Blaník, L-23 Super Blaník and L-33 Solo.

During the 1960s LET’s engineers developed a 19 seat commuter turboprop – the L-410 Turbolet, of which more than 1200 were produced. This popular aircraft went through a number of improvements and modernisations and the latest types, the L 410 UVP-E20 and L 420 are EASA and FAA certified respectively.

The largest Czech transport aircraft Let L-610 was produced in 1988 only in a prototype form and displayed at the Paris Airshow. Production was cancelled due to lack of funding. There were 8 prototypes made in the factory.

The all-metal Blaník sailplane was produced in the largest quantities of any sailplane, with over 3000 manufactured since the first rolled off the production line in 1958. In 2005 it was still in production as the L23 Super Blaník variant.

51% of the company's shares was purchased by UGMK in 2008; UAC has shown interest in acquiring the control of the company, as well.

AIRCRAFT

Aero Ae-45S and Aero Ae-145 - production 1951-1961, produced 390 planes
 Let C-11 - Czech production version of the Soviet Yakovlev Yak-11. 707 planes were produced in 1953-1956.
 Let L-200 Morava - produced 361 planes in 1957-1964.
 Let / Zlin Z-37 Bumble Bee
Let L-610 - produced only 6 flying prototypes in 1988-1997, the largest ever designed aircraft in the country.
 Let L-410 Turbolet - since 1971, produced more than 1200 planes.
 Let L-410 NG - new generation of L-410, since 2018.

 GLIDERS

Let L-13 Blanik
 Let L-23
 Let L-33
 Let LF-109 Pionýr
 Let TG-10

Source: Wikipedia