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 typeHybrid, 2-stroke, 1 cylinder
Weight2.5 kg / 5.5 lbs8.9 kg / 19.6 lbs
Displacement74 cc.124 cc.
Length x width x height140 x 160 x 200 mm 5.5 x 6.3 x 7.9 in450 x 300 x 150 mm 17.7 x 11.8 x 5.9 in
Bore45 mm54 mm
Stroke45 mm54 mm
Power18 hp at 9000 rpm28 hp at 8800 rpm
Maximum Continuous Speed9000 rpm10000 rpm
GeneratorBuilt-in 4 kWBuilt-in 11 kW
IgnitionElectronic CDIElectronic CDI, Twin spark plug. Variable ignition front
CoolingLiquid cooling, pressured thermostated system with external
electric cooling pump and radiators
Fuel systemElectronic Fuel InjectionElectronic Fuel 2-stage Injection. Throttle body + Transfer port
Fuel typeWide range of automotive and aviati n gas, 2% premix w/TS Oil.
External lubrication system options available
Fuel consumption200-220 g/kW/hr
TBO (estimate)Up to 500 hours
Preferred oil typeAPI TC
Fuel to oil mixturePremix 2%, Automix – 0,5-1%.
Sensors/TelemetryEGT – 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
ControlCAN 2.0B J1339/29 bit
CAN 2.0B J1339/29 bit ADLM+TrueTorque
Electric SystemInternal alternator/starterInternal alternator/starter. Internal starter batter pack 5Ah

Engine layout

  1. Cylinder cover
  2. Cylinder
  3. Reductor case
  4. Alternator/Starter rotor
  5. Throttle body
  6. Intake air resonator/silencer/filter
  7. Resonator
  8. Radiator
  9. ECU/Battery Unit
  10. Coil
  11. Spark plug
  12. 1st stage Injector
  13. Cooling pump
  14. Silencer
  15. Throttle servo/sensor
  16. Cooling liquid temperatiure sensor
  17. Shaft flange
  18. 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