I've accidentally found the following in factorio-current.log, right after the game load. I guess it is related to the Helicopters mod, but it might as well be related to Aircraft Realism.

15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 0): ROOT.car.heli-placement-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 5e-06): ROOT.car.heli-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 0): ROOT.car.heli-flying-collision-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 0): ROOT.car.heli-landed-collision-side-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 0): ROOT.car.heli-landed-collision-end-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 0): ROOT.car.heli-body-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 0): ROOT.car.heli-shadow-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 2e-06): ROOT.car.heli-burner-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 0): ROOT.car.heli-floodlight-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 0): ROOT.car.rotor-entity--.burner
15.174 Warning EnergySourcePrototype.cpp:91: emissions used, use emissions_per_minute (proposed value 0): ROOT.car.rotor-shadow-entity-_-.burner