One of the most recognizable parts of an airplane is the aircraft propeller. Propellers, often referred to as “props,” are also called as airscrews — and it’s easy to see why. To push a screw into the wall, you apply a clockwise turning force to the head with your screwdriver. The spiral groove (sometimes called a helical thread) on the screw’s surface converts the turning force into a pushing force that drives the screw into the wall and that’s pretty much what the first airplanes were. Planes took to the sky when the Wright brothers figured out how to combine engine-powered propellers and wings so they could go forward and upward at the same time.

A propeller is a machine that moves you forward through a fluid (liquid or gas) when you turn it. Though it works the same way as a screw, it looks a bit different: usually, it has two, three, or four twisted blades (sometimes more) poking out at angles from a central hub spun around by an engine or motor. The different types of propellers are:

Fixed Pitch Propeller:

Made in one piece, a fixed pitch aircraft propeller has only one pitch setting possible. Normally, it consists of two blades made of wood or metal.

• Wooden propellers are created with separate layers of wood. Wooden propellers were popular on personal and business aircraft before World War II.
• Metal Propellers were popular during the 1940s and were common on military aircraft., Metal propellers are created from heat-treated aluminum alloys. They are used extensively in the construction of propellers for modern aircraft.
• Composite Propellers of a variety of materials usually wood, fiberglass etc.

The new McCauley Propeller Systems Blackmac Carbon Series propeller

Adjustable Pitch Propellers

An aircraft propeller that allows pitch adjustment. There are several types of adjustable pitch propellers, that are:

• Ground adjustable pitch propellers — A ground adjustable pitch propeller must be adjusted while the plane is on the ground and the engine is not running. The propeller usually has a split hub, and the blade angle is determined by the aircraft specifications.
• Two-position propellers: This type of propeller allows the pitch to be changed from one position to another while the airplane is in flight.
• Controllable pitch propellers: A pitch-changing mechanism allows the pilot to change the pitch of the propeller while in flight or while the engine is running. The pitch is changed hydraulically.
• Constant speed propellers: A constant speed propeller uses either a hydraulic or electric pitch changing mechanism. During the flight, the pitch automatically changes based on data entered by the pilot prior to the flight.
• Full Feathering propellers: A full feathering aircraft propeller reduces drag by turning the edge of the propeller to a better wind position. Feathering is necessary during engine failure or during engine shut off during flight.
• Reversing propellers: A reversing aircraft propeller is a constant speed propeller that can allow a negative blade angle to produce a reducing thrust in an aircraft. Large aircraft use reverse propeller thrust during landing.
• Beta Control propellers: A beta control propeller allows the pilot to reposition the angle of the propeller blade manually. Many pilots use this mechanism during taxiing for thrust reversing (turboprop engines only).

· Counter-rotating propellers: Counter-rotating propellers are sometimes used on twin-engine and multi-engine aircraft with wing-mounted engines. These propellers turn in opposite directions from their counterpart on the other wing to balance out the torque. They are sometimes referred to as “handed” propellers since there are left hand and right-hand versions of each prop. counter-rotating propellers usually spin “inwards” towards the fuselage.

The W-wa Jeziorki

· Contra-rotating propeller: A contra-rotating propeller or contra-prop places two counter-rotating propellers on concentric drive shafts so that one sits immediately ‘downstream’ of the other propeller. This provides the benefits of counter-rotating propellers for a single powerplant. The forward propeller provides the majority of the thrust, while the rear propeller also recovers energy lost in the swirling motion of the air in the propeller slipstream.