How the aircraft noise can be measured?

The decibel ( db ) is the unit used to measure the intensity of a sound. The A weighted noise level has been adopted by the FAA as the accepted measure to consider aircraft noise. For noise sources in motion, like aircraft, noise levels can change over time.

Which instrument used for noise measurement?

sound level meter
What types of instruments are used for measuring noise? The most common instruments used for measuring noise are the sound level meter (SLM), the integrating sound level meter (ISLM), and the noise dosimeter.

What is jet engine noise measured at?

The sounds associated with jet planes measure between 120 and 140 decibels. Any sound above 85 decibels has the potential to cause hearing damage, especially with frequent or prolonged exposure.

How can aircraft engine reduce noise?

Sound absorbing ‘liners’ placed on the inner surfaces of an engine in the intake and the exhaust are an important method for reducing fan noise, the largest single source of engine noise both at take-off and approach. There is growing interest in fuel efficient, advanced open rotor (AOR) powered aircraft.

How is the noise of an aircraft measured?

Measurement of Aircraft Noise 1.1.1 Noise is described as unwanted sound. The two main components of a sound event are the loudness and pitch.

How are noise levels defined by the FAA?

The U.S. noise standards are defined in the Code of Federal Regulations (CFR) Title 14 Part 36 – Noise Standards: Aircraft Type and Airworthiness Certification (14 CFR Part 36). The FAA publishes certified noise levels in the advisory circular, Noise Levels for U.S Certificated and Foreign Aircraft.

When did the aviation noise and Capacity Act start?

In 1990, Congress passed the Aviation Noise and Capacity Act, which required that by the year 2000 all jet and large turboprop aircraft operated at civilian airports be Stage 3. All certified aircraft flying in the United States need to be Stage 3 or quieter.

Why do we need noise certification for aircraft?

The noise certification ensures that the latest safe and airworthy noise reduction technology is incorporated into aircraft design and enables the reductions in noise experienced by communities. As noise reduction technology matures, the FAA works with the international community to determine if a stronger noise standard is needed.