Version: SU13 (also observed in earlier sim versions)
Frequency: Consistently
Severity:
Context:
Documented helicopter secondary rotor config options don’t have an effect on the flight dynamics or CFD visualization.
Bug description:
Per the documentation on helicopter flight model here: flight_model.cfg - [HELICOPTER]
[SECONDARYROTOR] flight model section indicates support for cyclic_pitch_centre and cyclic_bank_centre.
This parameter describes the rotor axis default deflection, according to the helicopter design. This affects not only the tendency of the helicopter to pitch or roll when hands are free, but also the angular position of its body under the rotor in the flight.
Based on this, I expect that a canted tail rotor (like UH60 or H160) is possible by adjusting this angle. Once doing so, I expect to see the CFD visualization show a change vertically in the airflow moving through the tail rotor, and for the hands on feeling (longitudinal CG) to be represented differently in the flight model.
Repro steps:
- Using a dummy helicopter project, edit flight_model.cfg, [HELICOPTER], cyclic_pitch_centre. Set the value to
20degrees. - Load the helicopter and enable CFD debug visualization.
Expected:
- CFD to show airflow moving through the tail rotor with upward or downward ‘curve’
- Hands-on feeling to represent additional (or loss of) vertical lift from the tail rotor.
Observed:
- CFD appears to be the same
- Hands-on feeling appears to be the same
It’s possible that these parameters aren’t intended for the tail rotor, but we’d like to see this working as it would increase the fidelity of helicopters with canted tail rotors.