What is aircraft noise, and how is it generated?
Aircraft noise is sound emitted by aircraft during operation, which results from the movement of the aircraft through air and the propulsion required to do so. In specific, it is caused by:
- Engine noise
- Combustion
- Fast moving parts, e.g. the fan or propeller
- Hot exhaust air mixing with ambient air
- Airflow around the airframe
- Flaps
- Landing gear
- Fuselage and wings
In general, the engines will cause the most noise during take-off when they are running a high power settings. During approach, not much thrust is needed and noise caused by airflow around the airframe will be more apparent. Different aircraft produce different noise depending on size, engine type & number and other factors.
What influences aircraft noise?
The aircraft noise observed on the ground can sound very different depending on a number of factors including:
- The phase of flight (departure, cruise, approach)
- The altitude above the ground
- The lateral distance from the observer
- The weather conditions
Whilst these factors influence the sound that a noise monitor would measure, the perception of noise by humans is more complex. It depends on our local soundscape (or the day-to-day noise that we all experience) how much, or how little aircraft noise we receive.
For example, if you live in a noisy area, potentially within a town or city, or close to a road, the background noise level from those sources is likely to mask the sound of aircraft noise. Conversely, in a quiet area the masking effect isn’t present and the same aircraft is likely to be more noticeable.
It is important to note that annoyance is a personal experience, what might be annoying to one person may not be annoying to another. The airport takes noise monitoring seriously and has an active programme to monitor, analyse and report on the aircraft and background noise level in the local community.
Has aircraft noise changed?
Modern aircraft produce far less noise than older aircraft, producing around 90% less noise than the aircraft which were operating in the 1960s and the noise contour around London Gatwick has recently reduced in size despite a rise in traffic (not including the COVID-19 pandemic period).
This portal has been designed to provide transparent information on the traffic and noise levels. London Gatwick will keep the public informed through our engagement groups.