Aircraft Noise Levels & Stages
Aircraft noise is regulated through standards. These standards are set internationally and are applied when an aircraft is acquiring its airworthiness certification. The standard requires that the aircraft meet or fall below designated noise levels.
The FAA has undertaken a phase out of older, noisier civil aircraft, resulting in some stages of aircraft no longer being in the fleet. Currently within the contiguous US, civil jet aircraft over 75,000 pounds maximum take-off weight must meet Stage 3 and Stage 4 to fly. In addition, aircraft at or under 75,000 pounds maximum take-off weight must meet Stage 2, 3, or 4 to operate within the U.S. In addition, by December 31, 2015, all civil jet aircraft, regardless of weight must meet Stage 3 or Stage 4 to fly within the contiguous U.S. Both Stage 1 and Stage 2 helicopters are allowed to fly within the U.S.
Noise certification regulation
FAA regulates the maximum noise level that an individual civil aircraft can emit by requiring aircraft to meet certain noise certification standards. Each noise certification standard is designated as a different stage in the U.S. Stages and noise standards are defined in the Code of Federal Regulations, 14 CFR 36, Noise Standards: Aircraft Type and Airworthiness Certification. The FAA advisory circular on the Noise Levels for U.S Certificated and Foreign Aircraft provides noise level data for aircraft certificated under 14 CFR 36 and categorizes aircraft into their appropriate stages.
Any aircraft that is certified for airworthiness in the U.S. needs to also comply with noise standard requirements to receive a noise certification. The purpose of the noise certification process is to ensure that the latest available safe and airworthy noise reduction technology is incorporated into aircraft design and enables the noise reductions offered by those technologies to be reflected in reductions of noise experienced by communities.
As noise reduction technology matures, the FAA works with the international community to determine if a new stringent noise standard is needed. If so, the international community embarks on a comprehensive analysis to determine what that new standard will be.
For civil jet aircraft, there are four stages identified, with Stage 1 being the loudest and Stage 4 being the quietest. For helicopters, two different stages exist, Stage 1 and Stage 2. As with civil jet aircraft, Stage 2 is quieter than Stage 1. In addition, the FAA is currently working to adopt the latest international standards for helicopters, which will be called Stage 3 and will be quieter than Stage 2.
Currently, the FAA has aircraft standards up to Stage 4 (Chapter 4 internationally) for jet aircraft. The international community is looking to approve a more stringent standard in 2013 which the FAA will call Stage 5, which will be effective for new type certificates after December 31, 2017 and December 31, 2020, depending on the weight of the aircraft.
For helicopters, the FAA currently has a standard for Stage 2, but is currently working to adopt the latest international standards, called Stage 3. We hope to issue a final rule on Stage 3 helicopters in early 2014.
The FAA Modernization and Reform Act of 2012, in Section 513, had a prohibition on operating certain aircraft weighing 75,000 pounds or less not complying with Stage 3 noise levels.
On July 2, 2013, the FAA published a Final Rule in the Federal Register for the Adoption of Statutory Prohibition the Operation of Jets Weighing 75,000 Pounds or Less That Are Not Stage 3 Noise Compliant. In 1990, Congress passed the Aviation Noise and Capacity Act, which required that by the year 2000 all jet aircraft at civilian airports be Stage 3 aircraft.