About us
UAVHE (Unmanned Aerial Vehicle Hybrid Engines) is an engineering company focused on design and development of compact engines. We use high-end spacegrade alloys and modern technologies to create classy engines for different applications and particularly for companies, who embed engines in UAVs
Our engines
PT1/74 and PT1/124 are superlight 2-stroke hybrid engines with a single cylinder, integrated generator, mechanical transmission and reserve power supply built for helicopter-type UAVs or UAVs with electrical transmission. These engines are highly effective for sustained operation at constant speeds
Key features
- Efficient fuel consumption (especially when operating in a narrow speed range)
- Fuel quality measurement on each cycle
- Liquid cooling system with external electric pump
- CAN bus communication
- Accurate crankshaft reading through direct connection of generator
- Very high reliability, made for sustained operation at constant speeds
Integrated ECU - Built-in tutor (direct speed and torque control, as opposed to throttle control. Internally, the engine ECU software controls the basic parameters of the engine independently and provides the necessary speed and torque)
- Integrated self test software can predict different risks including possible breakdowns, provides solutions in abnormal situations
- Can be easily mounted almost everywhere
- Very low vibrations and noise level
- Integrated propulsion and energy systems
- Operates in rarefied air (up to 6000 m. AGL height limit)
- Wide operation temperature range: -40С – +40С
- Generator as a brake for decreased deterioration
Engine dimensions
Technical specifications
Engine type | Hybrid, 2-stroke, 1 cylinder | |
Weight | 2.5 kg / 5.5 lbs | 8.9 kg / 19.6 lbs |
Displacement | 74 cc. | 124 cc. |
Length x width x height | 140 x 160 x 200 mm 5.5 x 6.3 x 7.9 in | 450 x 300 x 150 mm 17.7 x 11.8 x 5.9 in |
Bore | 45 mm | 54 mm |
Stroke | 45 mm | 54 mm |
Power | 18 hp at 9000 rpm | 28 hp at 8800 rpm |
Maximum Continuous Speed | 9000 rpm | 10000 rpm |
Generator | Built-in 4 kW | Built-in 11 kW |
Ignition | Electronic CDI | Electronic CDI, Twin spark plug. Variable ignition front |
Cooling | Liquid cooling, pressured thermostated system with external electric cooling pump and radiators | |
Fuel system | Electronic Fuel Injection | Electronic Fuel 2-stage Injection. Throttle body + Transfer port |
Fuel type | Wide range of automotive and aviati n gas, 2% premix w/TS Oil. External lubrication system options available | |
Fuel consumption | 200-220 g/kW/hr | |
TBO (estimate) | Up to 500 hours | |
Preferred oil type | API TC | |
Fuel to oil mixture | Premix 2%, Automix – 0,5-1%. | |
Sensors/Telemetry | EGT – Exhaust gas temperature CHT – Cylinder head temperature CLT – Cooling liquid temperature IAT – Intake air temperature RPM – Rotation per minute CSP – Crankshaft Position KS – Knock sensor Airflow, Throttle position, Fuel Flow | |
Control | CAN 2.0B J1339/29 bit ADLM | CAN 2.0B J1339/29 bit ADLM+TrueTorque |
Electric System | Internal alternator/starter | Internal alternator/starter. Internal starter batter pack 5Ah |
Engine layout

- Cylinder cover
- Cylinder
- Reductor case
- Alternator/Starter rotor
- Throttle body
- Intake air resonator/silencer/filter
- Resonator
- Radiator
- ECU/Battery Unit
- Coil
- Spark plug
- 1st stage Injector
- Cooling pump
- Silencer
- Throttle servo/sensor
- Cooling liquid temperatiure sensor
- Shaft flange
- EGT sensor
Solution for reduced vibrations
Each cycle the synchronous generator mounted on the shaft alters between charging the batteries during combustion and regulating the shaft when air is compressed. This function reduces torsional vibrations and allows for more accurate and quicker control of speed and torque
Solution for decreased engine deterioration
A significant problem of common helicopter engines is an increased deterioration on engine braking. It happens when aircraft is lowered, the engine is at working revolutions, but the throttle valve is almost closed and engine is unloaded through the transmission by an oncoming flow (this is like driving downhill). In this mode throttle has to be closed to limit the growth of revolutions thus the engine receives less fuel and less oil with it and as a result gets increased deterioration. To avoid this problem, we invented some unique solutions
1) PT1 engines have a mode when the generator brakes the motor shaft to remove some of the load from the engine. At the first moment generator load increases and the maximum current goes to charge, and if more effective braking is needed, the generator performs like an electric motor creating the opposite moment while using battery power
2) PT1 is designed with the fuel flow through two injectors. One injector is located in the throttle assembly – and the mixture from it passes through entire engine, the second injector is placed directly at the intake port in the cylinder. Oil is fed through one of the injectors and the other one is used to supply clean fuel. Therefore, by changing the ratio of fuel supply between the injectors with the constant composition of the working mixture, we can regulate the proportions of oil in the fuel