What is aircraft noise, and how is it generated?

Noise from aircraft is generated from both the engines and the airframe, and examples of each are detailed below:

• Engine noise
  • Combustion
  • Engine parts such as the fan or propeller
  • Exhaust
• Airflow around the aircraft’s frame
  • Fuselage and wings (aircraft body)
  • Landing gear
  • Flaps and air brakes

Aircraft produce the most noise during take-off, when the engines are producing the most power and thrust to accelerate the aircraft down the runway. When an aircraft is on approach, it is slowing down to land and hence the engines will be producing less thrust and therefore less noise. Airframe noise will be more apparent during this phase of flight. Different aircraft will produce different noise levels depending on the size and weight of the aircraft and the engine type fitted.

What influences aircraft noise?

Aircraft noise experienced on the ground can vary depending on a number of factors including:

• The operation is an arrival, a departure or an overflight from another airport
• Altitude
• Lateral distance
• Weather, including cloud cover and precipitation
• Wind strength and direction

Whilst these factors influence how noticeable noise is from an aircraft, our local surroundings can also influence how much, or how little aircraft noise we experience.

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 as 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. Despite this, the airport takes noise monitoring seriously and has an active program 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. We are seeing a continual transition to more modern quieter aircraft, with the Boeing 737-800 passenger aircraft being replaced with the Boeing 737-8200 Max. This is also apparent with Cargo operators, with new Boeing 777’s replacing older Boeing 747’s.

Take a look at our Noise Level Dashboard under the ‘Your Area’ heading to see how noise is recorded at our monitors.