A propeller is the apparatus or part of an aircraft that transforms rotational energy from the engine or any other part of the aircraft into propulsion.
There are different types of aircraft Propellers because it’s one of the necessary components; without it, it cannot fly.
Aviation welding professionals have created and tested numerous types of aircraft propellers in the aviation sector over the years.
A few had greater success than others. To help you understand the distinctions between the types of aircraft Propellers in the aircraft business, our blog post will describe them all.
1. Fixed-Pitch Propeller
A fixed-pitch propeller is first on our list of types of aircraft Propellers. As the name suggests, it has the blade pitch, or blade angle, integrated into the propeller.
Once the propeller is constructed, it is impossible to alter the blade angle. Typically, this kind of propeller is made of aluminum alloy or wood, and it is one piece of nature.
The optimal efficiency of fixed-pitch propellers is achieved at a single rotational and forward speed.
Any alteration to these parameters lowers the efficiency of the engine and propeller since they are made to fit certain airplane and engine speed requirements.
Fixed-pitch propeller aircraft are those with low power, speed, altitude, or range.
These types of aircraft Propellers are used in many single-engine aircraft and have the advantages of being less expensive and easier to operate.
The pilot in flight does not need to provide any control inputs for this kind of propeller.
2. Test Club Propeller
Test club propeller is also one of the types of aircraft Propellers. Reciprocal engines are tested and broken in at a test club.
They are designed to give the engine the proper load during the test break-in period. During testing, the multi-blade design additionally provides additional cooling airflow.
3. Controllable-Pitch Propeller
While the propeller is rotating, the pitch or angle of the blades can be changed with the controllable-pitch propeller.
As a result, the propeller can adopt a blade angle that will maximize performance under specific flying circumstances.
Pitch can be changed to any angle between a propeller’s minimum and maximum pitch settings, or it can have a restricted number of pitch positions, as with a two-position controlled propeller.
The engine rpm required for a given flight situation can also be reached using controllable-pitch propellers.
A constant-speed propeller is not the same as this kind of propeller.
The pilot must adjust the propeller blade angle directly when using the controllable pitch type.
However, the blade angle can be altered while in flight. Until the pilot modifies it, the blade angle won’t change again.
The next advance in propeller technology is the governor, which paves the way for constant-speed propellers equipped with governor systems.
A Hamilton Standard counterweight two-position propeller is an illustration of a two-position propeller. These days, not many propellers are in use.
4. Ground-adjustable Propeller
A fixed-pitch propeller is how the ground-adjustable propeller works. Adjusting the pitch or blade angle when the propeller is not rotating is possible.
The clamping mechanism that secures the blades in place is loosened to achieve this.
It is impossible to adjust the blade pitch while in flight to accommodate changing flight needs once the clamping mechanism has been tightened.
These days, aircraft rarely use ground-adjustable propellers.
5. Constant Speed Propellers
Because of the fluctuating engine load, the propeller naturally tends to slow down as the aircraft climbs and to speed up as it descends.
The speed is maintained as steady as feasible to produce an effective propeller.
The engine speed is maintained by adjusting the propeller pitch with propeller governors.
These types of aircraft Propellers’ blade angle reduces somewhat during an airplane climb so as to keep the engine speed from dropping.
If the throttle is not adjusted, the engine can continue to produce power.
The airplane’s blade angle increases enough during a dive to prevent overspeeding while the power output stays constant at the same throttle level.
The blade angle changes as necessary to maintain a steady engine rpm if the throttle setting is altered rather than the airplane’s speed being modified by rising or descending.
Variations in the throttle setting correspond to variations in the power output, not the rpm.
Engine rpm is maintained by the governor-controlled, constant-speed propeller, which automatically modifies the blade angle.
One kind of pitch-changing mechanism has a piston-and-cylinder system and is powered by oil pressure (hydraulically).
The cylinder may move over a fixed piston, or the piston may move within the cylinder.
Different mechanical linkages transform the piston’s linear motion into the rotational motion required to adjust the blade angle.
Gears, the pitch-changing device that rotates the butt of each blade, could be the mechanical link.
Every blade has a bearing installed on it so that it may spin and change pitch.
With types of aircraft Propellers systems, the control system uses a governor to change the pitch without the pilot’s awareness to keep the engine running at a predetermined rpm within the propeller’s specified range.
For instance, the propeller must slow down if the engine speed increases and an overspeed condition arises.
The controls raise the blade angle automatically until the desired rpm is restored.
A good constant-speed control system maintains a constant rpm practically constantly by responding to such slight fluctuations in rpm.
An opposing force acts on each constant-speed propeller against the governor’s oil pressure.
As the propeller rotates, flyweights fixed to the blades cause the blades to rotate in a high-pitch direction.
Spring pressure, aerodynamic twisting moment, and air pressure (housed in the front dome) are additional forces that push the blades in the direction of high pitch.
6. Drag Propellers
In multi-engine aircraft, feathering propellers are required to minimize propeller drag in the event of one or more engine failures.
In multi-engine aircraft, a feathering propeller is a constant-speed propeller equipped with a mechanism that adjusts it to pitch at an approximate angle of ninety degrees.
When the engine cannot generate enough power to turn the propeller, it is often feathered.
The aircraft’s drag is significantly reduced when the propeller blade angle is rotated parallel to the flight path.
The propeller stops spinning when the blades are parallel to the airstream, resulting in little to no windmilling. Aerodynamic forces hold the blades in place.
Most small feathering propellers operate at low pitch using oil pressure and at high pitch using blade flyweights, springs, and compressed air.
The latch locks the propeller at the low pitch position when it slows down during shutdown, preventing the blades from going to the feather position.
These are housed inside the propeller hub and can be either internal or external.
The latches cannot stop the feathering because centrifugal force keeps the blades off their seat during flight.
To keep the engine from starting with too much load, latches are necessary.
The engine would be subjected to an excessive load at a time when it is already prone to wear if the blade was in the feathered position when the engine was started.
7. Reverse Pitch Propeller
Reverse pitch propeller is ending our list of types of aircraft Propellers.
Some propellers have additional improvements to enhance their operating qualities, such as reverse-pitch propellers (mostly used on turboprops).
The feathering style of the propeller is seen in almost all reverse-pitch models.
When operating, the blade angles of a reverse-pitch propeller can be altered to a negative value, making it a controlled propeller.
The reversible pitch feature aims to provide a negative blade angle that pushes in the opposite direction of typical forward motion.
Normally, after landing, when the landing gear makes contact with the runway, the propeller blades can be reversed or put into negative pitch, which provides thrust in the opposite direction of the aircraft’s motion and slows it down.
Engine power is supplied to increase the negative thrust as the propeller blades enter a negative pitch.
This lessens ground roll after landing and stops the airplane aerodynamically.
In addition to minimizing brake wear, reversing the propellers causes the aircraft to descend rapidly on the runway immediately following touchdown.