AKL-201712 AviaCollection / AviaKollektsia series 12/2017: Aero L-29 Delfin Military Trainer Aircraft. Photos, schemes, colour pictures. 32 pages, soft cover, text in Russian.

THE CREATING OF THE AIRCRAFT
The first jet training variants of fighters appeared in the 1940s. in Germany, England, France, USA and USSR. At first, the only such aircraft in our country was the UTI Yak-17. These machines were produced by the aircraft factory number 31 in Tbilisi, and in small quantities. The most massive Soviet jet trainer aircraft (TCB) was the UTI MiG-15-two-seater version of the well-known fighter, very heavy, "gluttonous" and, most importantly, did not fully meet the requirements for a training aircraft. In addition, the cadets of aviation schools began to master it after acquiring stable skills in piloting a Yak-18 aircraft with a piston engine, which made it difficult and delayed the training of future pilots.
In the 1950s. in the countries of the socialist camp (Poland and Czechoslovakia) they began to develop jet trainers for initial training, and in Yugoslavia they took up a combat training machine. Naturally, the Soviet Union closely watched this process, while developing their own aircraft. The main active players in this "field" were OKB-115 in Moscow, led by A.S. Yakovlev, and the design bureau of sports aviation in Kazan.
The transition to training pilots, bypassing piston aircraft, was also explained by the fact that military flight schools in the early 1960s. began to turn into higher educational institutions - this would lead to an extension of the term of study by one more year. They could refuse from the two-stage initial flight training only by switching to new TCB.
In 1957, OKB-115 of A.S.Yakovlev, in accordance with a government decree, began the development of a two-seater initial training aircraft Yak-104. The design was carried out for the R5-45 turbojet engine with a thrust of 1000 kgf, developed at OKB-45 under the leadership of N.G. Metskhvarishvili based on the lightest and most compact at that time domestic turbojet engine AM-5.
Prepared a full-size layout of the Yak-104, which was considered by the layout commission from 19 to 23 August of the same year. But soon, in connection with the termination of the development of the engine, the construction of a prototype of the plane was stopped.
However, a year later, on July 31, 1958, a decree of the Council of Ministers of the USSR No. 854-404 was issued on the construction of the Yak-104, but already with a promising lighter engine (jet accelerator) RU19-300 with a thrust of 900 kgf, which was developed in the design bureau of S. TO. Tumansky.
The following year, 1959, on February 4, another government decree was signed, which spoke about the development of the RU19-300 engine and the creation of a TR-1 (SA-4) training aircraft with an AM-5A engine with half the thrust in the Kazan design bureau of sports aviation. At the same time, the following were set: ceiling - 14-15 km, flight duration - 1 hour 10 minutes, take-off run - 400 m, landing run - 600 m and landing speed - 120 - 130 km / h.
The same document approved the main characteristics of the future Yak-104. In February 1961, a joint commission of the Air Force and DOSAAF rejected the TR-1 model due to its inconsistency with the requirements, and all attention was focused on the Yak-104.
Since the development of the domestic TCB was delayed, the military began to look closely at the progress of work on machines of a similar purpose in Poland (TS-11 "Iskra") and Czechoslovakia (L-29 "Dolphin"). The acquisition of training aircraft abroad could unload the Soviet aviation industry, allowing the main production facilities to be concentrated on solving global military problems. The leader in the tacit competition was Czechoslovakia, which for many years subsequently supplied jet training machines to the Soviet Union and almost all the countries of the Warsaw Pact.
This trend began with the L-29 (L-29) aircraft, which gave a huge boost to the Czechoslovak aviation industry. But today, few people know that, having opened the way for Czechoslovakia to the world aviation market, the domestic Yak-30 trainer, which most fully met the requirements of the Air Force of the Warsaw Pact countries, was sacrificed to "socialist integration".
Development of the L-29 began in mid-1955 at the Research and Flight Testing Institute (VZLU - Vyzkumny a zkusebni letecky ustav) under the leadership of experienced aircraft designer Zdenek Rublich on his own initiative.
Initially, in order to avoid losses of engine thrust, the aircraft was designed according to a new scheme, and with an eye to the UTI MiG-15, produced in Czechoslovakia under license under the designation CS-102.
In 1956, the development of the L-29 was included in the state plan, the government of Czechoslovakia allocated appropriate funding. Prepared and approved the task, agreed with the Czechoslovak Ministry of Defense and taking into account the requirements of the Soviet Air Force, which was considered the most important potential customer. The designers were required to provide a pressurized cabin and ejection seats. The arrangement of instruments on the boards had to comply with the standards for combat aircraft. Provided for a relatively small takeoff and run, as well as the possibility of operation from unpaved airfields. The requirement for the ease and safety of piloting the machine was especially emphasized. The flight range was increased by using outboard fuel tanks. To practice the skills of combat use on the L-29, the suspension of bombs and unguided missiles was provided,