Aircraft noise, some technical and political issues

Dr. Ruwantissa Abeyratne

NOISE POLLUTION: The world was first exposed to the magnitude of aircraft noise when the original prototype of the de Havilland Comet flew in July 1949.

The Comet, which was the first commercial aircraft to be powered by a jet engine, officially entered service on May 2, 1952. However, it was not until the long range Boeing 707, which was first delivered in 1958, entered service followed by the ubiquitous Douglas DC of 1962, that the full impact of aircraft noise became the focus of public attention.

Successive law suits in the nature of private actions in nuisance followed, prompting collective international action in the form of an international conference convened in London in 1966 which endorsed the concept of manufacturer control by certification of aircraft for noise levels.

In 1969, a special international meeting was held at the International Civil Aviation Organisation (ICAO) to address issues pertaining to aircraft noise, resulting in the creation of the ICAO Committee on Aircraft Noise (CAN) which in turn was charged with taking appropriate action on the aircraft noise issue.

The work of CAN led to the adoption in 1971 of Annex 16 to the Convention on International Civil Aviation, signed on December 7, 1944 in Chicago, which contained Standards and Recommended Practices on aircraft noise.

Technical issues

Aircraft noise is generated whenever the passage of air over the structure of the aircraft or flowing through its power plants cause fluctuating pressure disturbances which transform into auditory impulses in the human being.

Such impulses, called unwanted sound, not desired by the recipient, is measured. The underlying legal and political theme on aircraft noise is one of social expediency, largely categorised within the realm of the quality of life of communities affected by noise emitted by aircraft at take off, approach and landing.

One commentator cites the example of McDonnell Douglas which designed the MD90 (known for sometime as the quietest aircraft in its class) in response to increasing pressure at airports and restrictions placed on slots for landing.

However, the single most deterrent to aircraft noise is Annex 16 to the Chicago Convention which sets stringent standards on the quality of aircraft engines in the area of noise.

ICAO's philosophy in adopting International Standards and Recommended Practices to ensure optimal environmental protection in the field of aviation is based on the meaning and purpose of the Chicago Convention, the Preamble of which alludes to the importance of creating and preserving friendship and understanding among the people of the world and ensuring that aviation develops in a safe and orderly manner.

There could hardly be any friendship and understanding if aircraft of a foreign nation were to disturb the peaceful lifestyle of an urban community living under the flight path of an approaching aircraft. Similar pronouncements have been made at international fora on the importance of sustainable development and preservation of the quality of life.

Political issues

The major political issue concerning aviation and noise is that land is finite, for which a local community and the aviation industry may have a need, the latter to build airports in urban areas and the former to reside in. A new airport generates new opportunity for a burgeoning community, making it grow.

Employment opportunities offered by a new airport attract people who in turn need basic health, educational and other community facilities and a good standard of living which cannot be a reality if they are threatened by noise. This calls for airport regional planning and environmental impact statements, and, above all, political astuteness and integrity.

In a specific sense, the most contentious debate has been on the hush kit issue and the phasing out of aircraft having certain engine types which gave out more noise than was thought tolerable by urban communities. The Commission of the European Union, in April 1998, came up with a proposal which would prevent certain aircraft from operating into airports in the territory of the Union from April 01, 2002.

These aircraft are recertificated and hush kitted aircraft that would not exactly be included within the category three aircraft. On 29 April 1999, the Council of the European Union adopted a regulation that would come into effect in April 2002, with a proviso that a one year's grace period would be given to aircraft to comply with the EU's specifications, particularly with respect to ongoing negotiations with the United States.

The EU feels strongly that Chapter 2 aircraft cause both noise and gaseous emissions that are harmful to the health and well being of citizens of the European Union. Almost every airport in Europe has reached saturation point in tolerance to noise and noise capacity and the overall policy of the EU is to reduce noise levels of each individual aircraft progressively.

The hush-kit regulation of the EU, which disallowed member States from placing on their aircraft registers re-certificated aircraft which are originally fitted with Chapter 2 engines but are improved to meet Chapter 3 standards as of May 4, 2002, also contained a non- operation rule which prohibited non-EU member States' aircraft from operating to the territory of the EU if they were re-certificated.

However, two exceptions were recognised - one relating to an instance where the plane had already been on the register of the State on May 4, 2000 and the other if that plane operated air services to the Community from April 1, 1995 to 4 May 2000.

The EU approach to rejecting hush kitted aircraft even though they measured up to chapter 3 noise levels was that although Chapter 2 aircraft are modified to Chapter 3 levels by being fitted with hush kits, and although some noise reduction is achieved, they are not operated like Chapter 3 aircraft and do not conform to the spirit of Chapter 3 requirements.

The United States Senate, on July 22, 1999 passed a resolution to coerce the US State Department to lodge a complaint with the ICAO Council under the dispute resolution provision in Article 84 of the Chicago Convention. The complaint was aimed at requesting the Council of ICAO to determine whether the EU regulation was consistent with international aviation standards adopted under the aegis of the Chicago Convention.

The United States Senate also resolved to threaten to suspend all work on developing a State 4 noise abatement standard if the EU regulation was not suspended. Most business aircraft in the United States operating within the territory of the US, as well as aircraft operating commercial services from the US to Europe came within the ICAO and US Federal Aviation Administration approved 75,000 pound (or 34,000) kilogram) gross weight exemption for the Chapter 2 phase-out which was disregarded by the EU regulation and considered not acceptable.

The United States voiced its strong protest and opposition to the EU approach underlying the Regulation on the ground that it would discriminate against US carriers, hush kit and engine manufacturers resulting in a loss of at least two billion dollars to the US economy. The overall thrust of the US argument in favour of hush-kitted aircraft was that they complied with ICAO standards and that they effectively reduced noise emissions in aircraft.

As a political retort, the United States threatened to ban the Anglo-French Concorde SST, which at that time was considered by many as the noisiest aircraft ever certificated.

This resulted in discussions between the US and EU being accelerated, and the EU agreeing to delay implementation of the Regulation until May 2000, on the condition that the US would be actively involved in defining a next generation noise level under the aegis of ICAO.

ICAO has been a calming influence and a guiding force to all its 188 Contracting States regarding issues of aviation and the environment. The Organisation has recognised that the future development of aviation could increase and aggravate the problems of both aircraft noise and engine emissions unless action is taken to alleviate the situation.

With regard to the phase out issue, the 35th ICAO Assembly in 2004 exhorted States not to introduce any phase outs of aircraft which exceed noise levels in Chapter 3, Volume 1 of Annex 16 to the Chicago Convention, before considering four main considerations: whether the normal attrition of existing fleets of such aircraft will provide the necessary protection of noise climates around their airports; whether the necessary protection can be achieved by regulations preventing their operators from adding such aircraft to their fleets through either purchase, or lease/charter/interchange, or alternatively by incentives to accelerate fleet modernisation; whether the necessary protection can be achieved through restrictions limited to airports and runways the use of which has been identified and declared by them as generating noise problems and limited to time periods when greater noise disturbance is caused; and the implications of any restrictions for other States concerned, consulting these States and giving them reasonable notice of intention.

Balanced approach

Another area which impacts aircraft noise is land use planning. ICAO policy in this regard is clearly laid out in Assembly Resolution A 35-5 as basically hinging on land, use planning and management, which is one of the four principal elements of the balanced approach to noise management.

The number of people affected by aircraft noise is dependent on the way in which the use of land surrounding an airport is planned and managed and in particular the extent to which residential development and other noise sensitive activities are controlled, taking into consideration the risk that future growth may be constrained by inappropriate land use near airports.

The ICAO Assembly urged States that have phased out operations of Chapter 2 aircraft at their airports, as provided for in Appendix D to the Resolution A 35-5, whilst preserving the benefits for local communities to the greatest extent practicable, to avoid inappropriate land, use or encroachment whenever possible in areas where reductions in noise levels have been achieved.

States are also required to ensure that the potential reductions in noise levels gained from the introduction of quieter aircraft, particularly those complying with a new Chapter 4 standard, are also not compromised by inappropriate land use or encroachment.

From a practical standpoint, States are urged by the Resolution to minimise aircraft noise problems through preventive measures, where the opportunity still exists, by locating new airports at an appropriate place, as away from noise-sensitive areas; by taking the appropriate measures so that land use planning is taken fully into account at the initial stage of any new airport or of development at an existing airport; by defining zones around airports associated with different noise levels taking into account population levels and growth as well as forecasts of traffic growth and establish criteria for the appropriate use of such land, taking account of ICAO guidance; by enacting legislation, establishing guidance or other appropriate means to achieve compliance with those criteria for land, use; and by ensuring that reader, friendly information on aircraft operations and their environmental effects is available to communities near airports.

Impact on air transport

Development and environmental degradation are complimentary and the latter is a corollary to the former. Human activity continues to affect the environment and aviation is no exception. The enormous impact of rapidly growing mass air transport on the global environment, particularly through the expansion air ports and air routes calls for concerted action on a global scale aimed at confronting the issues.

Firstly, it must be noted that aircraft, which are the primary causes of pollution relating to environment, belong to airlines.

Therefore, by implication, airlines have to take steps of their own to alleviate the environmental problem, however small, caused by aviation. Indeed airlines have improved their product, as claimed by Giovanni Bisignani, Director General and CEO of the International Air Transport Association. Fuel efficiency of modern aircraft has been improved and, over the past 40 years, engine emissions have been reduced by 70 per cent per passenger kilometre. Aircraft noise has also decreased by 75 per cent.

The aircraft manufacturer has also consciously attempted to design aircraft which increasingly reduce engine noise. Major improvements in aircraft efficiency are claimed to have been achieved as early as the 1970s when the manufacturing industry introduced high by pass ratio engines on the twin engine aircraft that were being introduced.

Economic efficiency and technological innovation can effectively be harmonised through the reduction in unit costs as well as increases in capacity. For example, it is claimed that the Airbus A 380 can burn up to 20 percent less fuel per passenger than competing aircraft in its size category, while significantly reducing noise at airports. Fuel burn and efficiency also affects the ratio of noise reduction in an aircraft engine.

The role of ICAO as the regulator in environmental protection relating to aviation has already been discussed. In addition to its work on aircraft engine emissions and noise, ICAO has also been active in modernising the Rome Convention of 1952 relating to damage caused by foreign aircraft on the surface.

In considering issues relating to the justification for modernising the Rome Convention, no single issue stands out as much as environmental damage caused to persons and property on the surface by foreign aircraft.

The formal proposal made by Sweden at the 31st Session of the Legal Committee with regard to international rules contained in the Rome Convention of 1952, drew the attention of the Legal Committee to the fact that the concept of damage to the environment, including preventive measures and measures of reinstatement, was a factor to be considered and that environmental questions are of great importance.

Environmental awareness of carriers and their responsibilities in terms of minimally affecting the environment by their operations was considered a critical issue. The proposal also called for recognition that measures should be in place for the repair and reinstatement of the environment in case of damage.

A fortiori, the Committee was advised that such measures were already being contemplated in other fora, necessitating a revision of existing principles of liability under the Rome Convention. The modernising process is progressing steadily within under the stewardship of ICAO.

Obstacle to progress

The aviation industry is influenced by politics in most areas of its activity and environmental protection is no exception. The singular obstacle to meaningful progress is the lack of coordination.

Regulators, airlines, airports and manufacturers act separately in developing the overall aviation product and this separation has proved to be quite costly in achieving real value for all the work done so far individually by the players.

For example, fuel efficiency, which is initially achieved by the design of the aircraft and its engines, is later impacted by efficient air traffic management and effective and lean route structures.

This calls for cooperation and coherent coordination from the very commencement of an aviation plan between the manufacturer, the airline and the regulator, along with all the ICAO member States. Solutions must be sought not only through rigid and formal structures of international bureaucracy and politics but also through individual efforts in implementation through voluntary programmes calculated to maximise the effects of regulation.

The politics of aviation must be routed through and practiced through a collective look at both air transport economics and air navigational technology. This calls for a closer look at existing policies and positioning of bureaucracy and industry.

The writer is the Coordinator, Air Transport Programmes, International Civil Aviation Organisation, Montreal, Canada