The Air Transport White Paper notes for Heathrow that:
any further development could only be considered on the basis that it resulted in no net increase in the total area of the 57dBA noise contour compared with summer 2002, a contour area of 127 sq km. 1
The Civil Aviation Authority (CAA) suggests that 615,000 ATMs are possible in 2020, and 702,000 ATMs in 2030 whilst staying within the agreed noise limit (<127 km2 at <57 dBALeq). The CAA’s impact predictions rely heavily on assumptions about future aircraft, including whole new engine ‘families’ that don’t yet exist. They use information on possible new technologies from the Advisory Council for Aeronautical Research in Europe. We believe that 1. it is unlikely that all of the future noise reductions assumed by the CAA will take place, and 2. LeqdBA is not the (only) correct metric to use in predicting the noise impacts of aviation.
The industry often points to radical new technology on the horizon that will deliver very substantial future noise reductions. The implication of projects with titles such as the
Quiet Technology Demonstrator Programme is that at some point in the not-too-distant future aircraft noise will simply cease to be a problem. But if a three-runway airport in 2015 or 2020 is to remain within the Government’s contour target for the 57 dBALeq, substantially quieter aircraft will need to have been on the market for some years. Here we examine whether this is likely.
In 2000, the Advisory Council for Aeronautical Research in Europe (ACARE) published its 2020 vision for the air transport industry2. In relation to aircraft noise, it set itself ambitious goals to reduce perceived noise by 50% by 2020 relative to 2000, and to eliminate significant aircraft noise outside the airport boundary during the same period. In practical terms, this means reducing noise by 10 EPNdB3 per take-off, and keeping the 65 LDEN4 contour within the airport boundary.
These goals are aspirational and present significant challenges to manufacturers and the rest of the industry. The earliest implementation date for any of the technologies emerging from this work is likely to be 2010, by which time ACARE hopes to be able to demonstrate a reduction of 5 EPNdB for existing in-production aircraft as well as new designs.
ACARE has just announced that it has secured 2-years funding from the EU to undertake a comprehensive progress review of the ACARE 2020 goals. Although the review will not commence until spring 2008, we understand that some progress has being made to date. Innovations in nacelle and nozzle liner concepts, inlet design and landing gear5 are all currently being used in flight tests. However, there is only limited scope for retro-fitting these technologies to the existing fleet (a new engine would probably be required,
1 ATWP 11.53
2 ACARE’s brief is to create and maintain a Strategic Research Agenda (SRA). The first SRA
was published in October 2002 and included ‘Environment’ as a top level objective, with SRA2 appearing in October 2004.
3 Effective Perceived Noise (Level) in Decibels
4 Level Day Evening Night – a 24 hour Leq with weightings for evening and night periods
5 See for example