Description

Noise has historically been the principal environmental issue for aviation. It remains high on the agenda of public concern. Noise disturbance can have significant adverse effects on people living close to an airport, including: interference with communication, sleep disturbance, annoyance responses, learning acquisition, performance effects and cardiovascular and psycho-physiological effects. Doubling the distance between yourself and the source of a noise effectively cuts the intensity of the sound by 6 dBA; i.e. the noise will only sound about 25% as loud.

Annoyance is the most widespread problem caused by environmental noise. Annoyance reflects the way that noise affects daily activities. People's social circumstances, their culture and the environment in which they live can all determine the degree of perceived annoyance for a given noise level. However, quality of life will suffer when people are disturbed or annoyed by noise. Sleep disturbance caused by environmental noise can also affect the quality and quantity of sleep, leading to drowsiness and poor performance the following day.

Aircraft Design

All commercial aircraft must meet the International Civil Aviation Organisation (ICAO) noise certification standards, which are detailed in ICAO Annex 16: Environmental Protection, Volume 1 - Aircraft Noise. These apply to aircraft designs and types when they are first approved for operational use, and they have been progressively tightened since the initial ICAO standard was adopted in 1971. (These standards are detailed in ICAO Annex 16 Volume 1, Chapter 2). This was for aircraft designed prior to 1977. Since 1977, any new aircraft designs have been required to meet stricter (Chapter 3) or later standards. On April 1st 2002 most aircraft not meeting Chapter 3 standards were phased out by international agreement. From 1 January 2006, a more stringent standard (Chapter 4) has been applied for new aircraft designs. This standard will be one third quieter than the existing Chapter 3 standard.

Operating Technique

Aeroplane operating procedures for noise abatement should comply with the provisions of ICAO Doc 8168 (PANS-OPS), Volume I, Section 7, and noise abatement procedures specified by an operator for any one aeroplane type should be the same for all aerodromes. (ICAO Annex 6: Aircraft Operations, Chapter 4, Section 4.4.9)

JAR-OPS 1.235 requires that:

1. An operator shall establish operating procedures for noise abatement during instrument flight operations in compliance with ICAO Doc 8168 (PANS-OPS), Volume I, Section 7; and that
2. Take-off climb procedures for noise abatement specified by an operator for any one aeroplane type should be the same for all aerodromes.

Noise Abatement Procedures

Many airports implement noise mitigation techniques, including the following:

• Defining noise abatement procedures that avoid residential areas as far as possible and avoid over-flying sensitive sites such as hospitals and schools
• Using continuous descent approaches and departure noise abatement techniques
• Ensuring that the optimum runway(s) and routes are used as far as conditions allow
• Avoiding unnecessary use of auxiliary power units by aircraft on-stand
• Building barriers and engine test-pens to contain and deflect noise
• Towing aircraft instead of using jet engines to taxi
• Limiting night operations
• Limiting the number of operations or the extent of a critical noise contour
• Providing noise insulation for the most severely affected houses
• Applying different operational charges based on the noisiness of the aircraft
• Monitoring individual noise levels and track keeping and penalising any breach

Aircraft experiencing an emergency situation are not expected to comply with noise abatement procedures.

Further Reading

• ICAO Annex 6 (Aircraft Operation)
• ICAO Doc 8168 (PANS-OPS), Volume I, Section 7
• JAR-OPS 1.235
• EUROCONTROL Environment