That's correct. The bar majority of piston engine aircraft use a direct drive from engine to propellor.
More complex aircraft use a constant speed propellor as a form of gearbox, allowing the blade pitch to be altered while maintaining a constant blade rpm.
motorslug t1_jdvxou6 wrote
Reply to comment by DreamyTomato in Does living in an airplane flight path, near an airport, pose a health risk? What happens to the lead from the jets fuel? by [deleted]
That's correct. The bar majority of piston engine aircraft use a direct drive from engine to propellor. More complex aircraft use a constant speed propellor as a form of gearbox, allowing the blade pitch to be altered while maintaining a constant blade rpm.