I'm not convinced that an engine or accessories could generate significant harmonics in the VHF range
I am about as far from being an expert on things radio as it is possible to be...
That said, I would be pretty sure that the suppression of RT emissions from aero-engines and accessories is a significant issue, and failure of suppression equipment frequently causes disruption to VHF voice reception and transmission.
Have you never had the experience of a passing motorbike causing the television or radio in your house to flicker or crackle?