Nighttime Noise Rule Information
Ronald Reagan Washington National Airport (DCA) has a long history of nighttime noise restrictions between 10 p.m. and 7 a.m. The restrictions are not a curfew on flights, but rather a prohibition for certain types of aircraft whose designs and weights would make them more prone to higher noise levels on takeoff or landing.
The DCA Nighttime Noise Rule was implemented in 1981, when aircraft were generally much louder than today’s jets and when DCA was operated by the Federal Aviation Administration (FAA). The DCA Nighttime Noise Rule was one of the first of its kind in the nation, and it helped usher in federal requirements for quieter aircraft. While these laws require airlines to fly quieter planes, they also prohibit individual airports from creating noise rules. But because DCA’s rule already existed, it has been allowed to remain in effect.
The DCA Nighttime Noise Rule’s design-and-weight configurations for aircraft are intended to limit their average noise output during takeoff and landing at certain points near the runway to the following levels:
- Departures - 72 dBA as determined during the FAA aircraft noise level certification process
- Arrivals - 85 dBA as determined during the FAA aircraft noise level certification process
- dBA is A weighted decibel and is the standard unit for measuring noise. The noise limits (72 on departure and 85 on arrival) are based on sleep disturbance research data.
The Metropolitan Washington Airports Authority enforces the DCA Nighttime Noise Rule based on noise-related data provided by FAA’s standard certification processes for aircraft operating with all available engines. This method allows airlines and pilots to determine, in advance of flight, whether their aircraft – based on design, weight and engine type – will comply with the DCA nighttime noise rule.
The certification process required by the FAA is summarized below and can be found in Federal Aviation Regulation Part 36 – Noise Standards: Aircraft Type and Airworthiness Certification.
The FAA noise certification process (see Figure 1), measures aircraft noise levels at two points. On approach, noise is measured on the ground at 2,000 meters before the end of the runway. On takeoff, noise is measured on the ground at 6,500 meters from the start of the takeoff roll. The FAA compiles and tabulates noise data on all aircraft types and engine configurations that operate in the United States using this method. This data – which is used to determine compliance with the D CA nighttime noise rule – can be found in FAA Advisory Circular 36-3H, “Estimated Airplane Noise Levels in A-Weighted Decibels,” dated May 25, 2012. FAA AC 36-3H