Scientists and engineers from the Institute of Engine and Power Plant Engineering (IEPPE) at Samara National Research University have developed and tested a prototype of a lightweight, compact piston internal combustion engine designed for unmanned aerial vehicles (UAVs). Named “Dobrynya,” the engine is assembled entirely from domestically produced components. Notably, it incorporates composite materials in its construction—a first for engines of this class—significantly reducing its weight compared to foreign counterparts.
The project received financial support through a grant from the Foundation for the National Technology Initiative (NTI). The engine was developed at the Small Innovative Enterprise “Aerospace Technologies,” established at Samara University.
“A scientific and engineering team from the Engine and Power Plant Engineering has developed a prototype piston internal combustion engine for UAVs. Key features of this engine include fully domestic components and a high degree of standardization in its core structural elements, enabling the future production of an entire family of UAV engines based on this design. Moreover, polymer composite materials have been used for the first time in engines of this class as structural components, resulting in a weight reduction of approximately 15% compared to similar imported models. The prototype has successfully passed flight tests, confirming its declared technical specifications,” said Vitaly Smelov, Director of the Engine and Power Plant Engineering at Samara University.
The innovative development is a single-cylinder, two-stroke internal combustion engine with the following parameters:
Power output: 5 hp
Displacement: 55 cm³
Fuel consumption: up to 2.2 liters per hour
Weight: approximately 1.5 kg
Dimensions: 20 cm (length) × 9.5 cm (width) × 18 cm (height)
Fuel type: AI-92 or AI-95 gasoline
Flight tests were conducted at the university’s training airfield. The prototype was installed on a glider with a total payload of approximately 10 kg. Test flights were carried out under challenging weather conditions, including low ambient temperatures, and the engine operated without any issues.
Concurrently with the engine prototype development, the university’s IEPPE research team also designed a full-featured electronic engine management system as part of its scientific program. This system includes distributed fuel injection, an electronic throttle actuator, and a microprocessor-controlled ignition system. It is intended for use in engines with displacements ranging from 50 to 300 cm³ and configurations from one to four cylinders.
“The system was installed and tested on our piston engine prototype. The engine demonstrated stable and smooth operation across all modes and revealed significant potential in terms of power performance. This confirms the high reliability and efficiency of the control system parameters engineered by our team,” emphasized Andrey Bulatov, Project Lead and Associate Professor at the Advanced Aerospace Engineering School of Samara University.
According to Mr. Bulatov, a pilot model of the piston engine is scheduled for further testing by summer 2026. Additionally, work is currently underway to develop an entire family of aviation piston engines based on this platform, featuring various configurations and applications. All engines in this series will carry the “Dobrynya” name, distinguished by numerical suffixes according to model—e.g., “Dobrynya-2,” “Dobrynya-4,” and so on.
“Technically, the engine family has already been designed, and we are now proceeding to manufacture the first pilot units. The lineup includes single-, twin-, and four-cylinder engines, as well as hybrid power systems for multirotor UAVs—in which the internal combustion engine generates electricity to power the drone’s electric motors. Some models will feature carburetor-based fuel systems, while others will employ electronic fuel injection with electronic throttle control. These engines are expected to find applications not only in unmanned aviation but also in ground-based compact machinery, such as lawn mowers, brush cutters, and other handheld tools,” concluded Andrey Bulatov.
