NoisedB – Noise certification glossary

Aircraft Attributes

Manufacturer: Company that designed and manufactured the aircraft.
Model: Commercial designation of the aircraft (e.g., A320, B737).
Version: Specific variant of the model (e.g., A320-214, B737-800).
MTOW (Maximum Take-Off Weight): Maximum takeoff weight: the maximum authorized weight of the aircraft at the time of takeoff, expressed in kilograms (kg).
Number of Engines: Number of engines installed on the aircraft.
Engine Type: Technical designation of the engine equipping the aircraft.

Chapter: Noise certification standard defined by ICAO (International Civil Aviation Organization). Chapters define acceptable noise limits for aircraft.
Chapter 2: Obsolete noise standard, banned since 2002. Very noisy aircraft.
Chapter 3: Noise standard applicable to aircraft certified between 1977 and 2006. Quieter than Chapter 2.
Chapter 4: Stricter noise standard than Chapter 3, applicable since 2006. 10 EPNdB reduction compared to Chapter 3.
Chapter 14: The strictest noise standard currently in force, applicable since 2017 (includes Stage 5 aircraft). Additional 7 EPNdB reduction compared to Chapter 4.
Stage 5: Noise standard equivalent to Chapter 14. Stage 5 aircraft are automatically classified as Chapter 14.
EPNdB (Effective Perceived Noise in Decibels): Unit of measurement for effective perceived noise, taking into account duration, frequency and intensity of noise. Used to assess compliance with certification standards.

Approach: Measurement point located 2,000 meters before the runway threshold, at ground level. Measures noise during the approach and landing phase.
Lateral / Flyover: Measurement point located 450 meters from the runway centerline, when the noise level is maximum. Measures noise perceived by residents located on the sides of the runway.
Departure / Takeoff: Measurement point located 6,500 meters after the start of the takeoff roll. Measures noise during the climb phase after takeoff.

EASA (European Union Aviation Safety Agency): European Aviation Safety Agency. Certification authority for aircraft registered in the European Union.
FAA (Federal Aviation Administration): United States Federal Aviation Administration. Certification authority for aircraft registered in the United States.
TCCA (Transport Canada Civil Aviation): Transport Canada Civil Aviation. Certification authority for aircraft registered in Canada.
ICAO (International Civil Aviation Organization): United Nations organization that establishes international civil aviation standards, including noise certification standards (Chapters).