Top Three Causes of Aircraft Vibrations

Aircraft vibration is one of the technical or mechanical problems that most aircraft experience. Every aircraft is built with the intention of minimizing vibration to the lowest levels possible or eliminating it completely. Increased vibration is uncomfortable for pilots and passengers and can be quite unnerving when one is 10,000 feet above the ground. Although technicians work hard to monitor vibration and eliminate it, most aircraft still experience this problem. Keep reading to learn the top three causes of aircraft vibrations.

Causes of Aircraft Vibrations

Although weather and wake turbulence are major contributors to vibration, they are not classified among the three top causes of aircraft vibration—which are discussed below. However, a vibration meter is not exempted from monitoring vibrations brought about by weather and turbulence in the air.

1. Aerodynamic Imbalance

The aerodynamic imbalance is one of the leading causes of vibration in aircraft. It mostly occurs when the rotation of the propeller is not installed in the most appropriate area by the technicians. In such a case, the center of gravity of the propeller does not coincide with the axis. Fan balance is very important because it produces the moving force needed by the aircraft. A poorly installed propeller can lead to fatal aircraft accidents.

Fan trim balance testing should be done regularly to test whether the propeller is in the right place. With a vibration meter, it will be easier to understand whether the propeller is the cause of the aircraft vibrations. When you are using the best vibration analyzer, you will be able to detect vibrations even when the aircraft or propeller is static.

2. Mass Aircraft Imbalance

Mass aircraft imbalance is another major leading cause of aircraft vibration. The weight of the aircraft as a whole unit needs to be distributed proportionally. However, it is important to note that distributing the weight of the aircraft may not be 100%. This leads to a situation where certain levels of vibration are expected. The ideal situation involves minimizing vibration to the lowest measurement through balance equipment.

Other multiple factors that cause mass aircraft imbalance include damaged propeller, manufacturer error, installation problems, poor maintenance, moisture and corrosion among others. However, with the right vibration meter at hand, it is easier to detect vibrations caused by such factors.

3. Fuel Flow and Bearing Vibrations

Vibration meter has also shown that fuel flow has some impacts on aircraft vibrations. The flow of fuel from the fuel tank to the engine has a significant impact on the overall balance of the aircraft, which brings about some unwanted vibration. However, it is worth noting that fuel flow vibrations have been accounted for by the manufacturer and therefore not dangerous.

Bearing vibration is a type of aircraft vibration that occurs when a helicopter rotor track and balance have not been checked. Continuous rotation of the propeller weakens the bearing at the bottom, which means that the center of rotation does not coincide with the center of gravity of the aircraft. Regular and quality maintenance for aircraft plays a vital role in eliminating bearing vibrations. A worn-out bearing should be replaced before it leads to intense vibrations to the aircraft.

Is Aircraft Vibration Dangerous?

The severity of an aircraft vibration depends on its levels. The industrial standard for aircraft vibrations is a scale of 0 to 1.2 inches per second (IPS). 0-.2 IPS is considered good and is usually expected from all types of aircraft when everything is working as expected. .21-.4 IPS is fair but can as well be eliminated through scheduled maintenance. .41-.6 IPS is slightly rough and usually occurs in extreme weather conditions or wake turbulence. However, aircraft vibrations of 1.01-1.2 IPS are very rough and dangerous. It can cause serious problems if an emergency landing is not deployed.

What Next?

As seen above, aircraft vibrations are common occurrences that should be expected. However, it is important to monitor vibrations using a vibration meter to understand the levels and also to deploy the necessary aircraft maintenance and prevent accidents.