Aircraft typically get airborne in one of two ways: by taking off horizontally from a runway or by lifting vertically from a fixed position. The most familiar thrust maker is a propeller, powered by one or more engines and mounted on the aircraft’s nose or wings.
Vertical-lift aircraft use one or more engine-driven rotors to generate lift. In both systems, the purpose is the same: to produce enough thrust or lift to leave the ground.
A propeller or rotor follows the same basic principle as a wing, with one flatter side and one curved side. Unlike a fixed wing, a propeller blade is twisted and tapered to produce more consistent thrust along its length. Since the blade tip moves faster through the air than the area near the hub, the twist and taper help balance the thrust.
Propeller and rotor design has advanced significantly since the hand-carved propellers the Wright Brothers used at Kitty Hawk. After each crash, they had to carve a new wooden propeller by hand—a difficult, time-consuming job.
In aviation’s early years, most aircraft used wooden propellers. Cutting machines and templates later made replacements more affordable and consistent. Wooden propellers are still made today with advanced cutting and carving equipment, and their main advantage remains their lighter weight compared with metal propellers.
The aircraft I flew all had metal propellers, each with its own FAA logbook and regular inspection and overhaul schedule. Before every flight, I checked the propeller’s leading edge for cracks or nicks. Even a small nick could unbalance the propeller, causing serious vibrations that might lead to engine failure—and a very bad day.
As carbon-fiber composites and manufacturing methods improved, advanced composite propellers became widely used. Strong and lightweight, they combine many of the best qualities of wood and metal propellers.
DUC Propeller, a French company, makes high-tech composite propellers and rotors. Its U.S. headquarters at Sebring Regional Airport distributes propellers shipped from France and installs them for customers nationwide. DUC Propeller US also plans to open a manufacturing facility at the airport. Many students in our high school aviation program have interned there, learning to install and balance propellers.
