Description: The article examines an approach to improving the trainer aircraft performance characteristics by selecting and replacing the propulsion engine. There are calculations of aircraft L-39 performance characteristics depending on different engine versions: AI-25TL (basic option), AI-25TLSH, AI-222-25, AI-222-28. The aircraft characteristics were examined based on the standard tasks to be solved when training the flight personnel: circuit flying, en-route flight, piloting and performing a battle task. According to the study results, engines AI-222-25 and AI-222-28 are excessive in term of the thrust for L-39. To improve aircraft L-39 performance characteristics, it is expedient to use an engine with the thrust from 20,6-21,6 kN. Increased thrust/weight ratio of the aircraft equipped with AI-222 line engines will make it possible to provide for additional weapon stations and increase the take-off mass of the aircraft. The article points out that L-39 aircrafts equipped with AI-222 engines can be upgraded t the level of a battle trainer or light combat aircraft.
Keywords: L-39 aircraft, engine, propulsion, integration, adjustment of characteristics, trainer aircraft, battle trainer aircraft