Praga E-112
The Praga E-112 was a prototype Czechoslovak training aircraft of the 1940s. It was built to meet a requirement for an elementary trainer for both the Czechoslovak Air Force and civil use, first flying in September 1947. After testing, it was rejected in favour of the Zlín Z-26, and no production of the E-112 followed.
Design and development
In 1946, a specification was issued for a two-seat basic training aircraft for use both by the Czechoslovak Air Force and civil users. The new aircraft was required to use a Walter Minor 4-III engine, and was to have a maximum speed of, a cruise speed of and to be able to climb to in 13 minutes, and have a ceiling of. Two designs competed to meet the specification, one from Zlín and one from the ČKD-Praga design team led by, the Praga E-112.The Praga design, which was very similar to the competing Zlín, was a tractor configuration cantilever monoplane of mixed wood and metal construction with a fixed tailwheel undercarriage. The low-mounted wing was made of wood, while the fuselage had a welded steel-frame structure with fabric covering. The crew of two sat in tandem under a three-part plexiglass canopy, and were provided with dual controls.
Construction of the prototype was assigned to Letov at their Letňany, Prague factory, but the quality of construction was poor, with the aircraft overweight and showing a poor surface finish, particularly compared to the Z-26. It made its first flight at Letňany on 14 September 1947. A number of modifications were made as a result of factory testing, including revised tail surfaces and a modified engine cowling to improve cooling, but a more significant problem was that the aircraft's propeller was unsuitable, so that the engine would not run at the required speed. Both the E-112 and Z-26 were delivered for evaluation in February 1948. The E-112's speed was slightly below the 200 km/h required by the specification, while its climb rate was much poorer than required, partly due to the poorly matched propeller and failed attempts to modify it to improve the aircraft's speed. As a result, the Z-26 was chosen to meet the requirement and ordered into production. Work continued to improve the E-112 into 1949, and fitting new propellers significantly improved performance, particularly climb rate, but this did not result in any production orders.