propeller

Each propeller has bearings with two races, or rings or tracks.

We could hear the whirring of the propellers before we could see the drone - barely visible as it sliced through the sky.

Upon the ship's return to Scotland in September, a gearbox and propeller fault were detected, and further investigation at Dale's Marine in Greenock revealed the rear of the ship was twisted.

Archer's Midnight aircraft is built with 12 engines and propellers, and produces "less noise and emissions than a traditional helicopter", according to LA28.

His carbon fibre creation, known as VX4, has eight propellers and looks like a giant drone, but what's crucial is that it doesn’t use fuel.