Growing Concerns

The need to burn extra fuel on account of congestion could well be avoided through better infrastructure and enhanced efficiency in ATM, through universal use of modern systems including ADS-B, RVSM, satellite navigation and related airborne equipment

All forms of combustion including fuel burned in the engines of aeroplanes release gaseous outputs, primarily carbon dioxide (CO2) that pollute the atmosphere with consequent long-term deleterious effects on the environment. According to the United Nations Intergovernmental Panel on Climate Change (IPCC), globally, the aviation industry as a whole accounts for two per cent of the total human-generated CO2 emissions. Although the targets set in the Kyoto Protocol pursuant the United Nations Framework Convention on Climate Change are focused on CO2 emissions, there are other greenhouse gases (GHG) such as methane, water vapour and oxides of nitrogen (NOx) that also contribute to global warming leading to climate change. The IPCC is, therefore, of the view that if these gases are also taken into account, the total contribution of aviation to climate change would be about three per cent.

Enter Regional Aviation

Driven by the steadily rising demand for air travel in the wake of resurgent economies over the last five decades, the global airline industry has been growing annually at an average of around nine per cent. Despite the current economic slowdown, the growth rate of the airline industry in the foreseeable future is expected to be high enough to generate global concerns about the growing impact of aviation on climate change. Meanwhile, a significant transformation that is taking place within the airline industry is the increasing share of regional aviation wherein lower capacity regional jets and turboprop aircraft are taking over from larger capacity airliners. Regional aviation aircraft operate on the low-density routes connecting a wide network of Tier -I and -II cities with major traffic hubs in what is described as a ‘hub and spoke’ arrangement. However, compared with the large airliners flying on long routes, fuel consumption per passenger kilometre on regional aircraft is higher. This is on account of shorter stage lengths and shorter flight time because of which airliners engaged in regional aviation are required to take off, climb, descend and land more often than aircraft operating on long routes. For every hour of flying, compared with regular airliners, regional aviation aircraft thus inherently spend more time on the ground with the engine running, as also operate flight profiles wherein fuel consumption rates are not optimum.

Another factor to be taken into account is the fact that regional fleets are inducting more jetliners than turboprops. When compared with turboprop aircraft, jetliners are less energy-efficient. While the engine efficiency of the regional jet has been improving continuously, that of the turboprop engine as compared with pure jet engines, has always remained higher by 10 to 30 per cent. However, despite the higher fuel efficiencies of turboprops, airlines are able to achieve higher load factors on regional jets. Also, for similar power output, the turboprop engine is heavier; adding to the weight of the aircraft and a disadvantage that partially degrades the benefits of higher engine efficiency. Aerodynamically, both jet and turboprop airliners display similar levels of efficiency.

As the growth potential of regional aviation is predicted to be high so also will be its contribution to environmental degradation through emission of GHG. Measures to reduce the impact of aviation on the environment must, therefore, necessarily take into account the growing share of regional aviation in the industry.

Challenges before the Industry

In comparison with other modes of transportation, the contribution of the aviation industry to climate change is relatively small. Nevertheless, the stakeholders of the industry i.e. both manufacturers and operators, are striving incessantly to minimise damage to the environment by the ever-expanding aviation activity. The focus of efforts to mitigate the adverse impact of the aviation industry has been on technological innovations in respect of both engines and airframe, development of alternative fuels and propulsion systems and enhancing efficiency of the operating environment through better infrastructure and more efficient air traffic management (ATM).

As the power plant on the aircraft is the primary source of GHG emissions, advancement in engine technology to reduce fuel burn is the first and the most logical step in technology evolution. This would provide cost efficient performance through reduced fuel burn and an environment friendly approach through reduction in emission levels. ATR of France is the first green-certified regional aircraft manufacturer, and armed with the ISO 14001 certification, it is a market leader in the world in this regime. The company aims to reduce the environmental footprint of its aircraft throughout its life cycle. In the regional aircraft segment, ATR has been producing regional aircraft, the ATR 42 and ATR 72, with high-technology engines and enhancing propeller efficiency of their aircraft to ensure that airlines benefit from unrivalled fuel efficiency and a remarkably low noise signature, all contributing to exceptional environmental performance. The notable achievements of ATR have been lowest CO2 emissions, 50 per cent reduction in fuel consumption per passenger kilometre and compliance with ICAO’s 1971 vintage standards and recommended practices for aircraft noise certification.

One of the leading manufacturers of aero engines and part of United Technologies Corporation, Pratt & Whitney is a world leader in the design and manufacture of aircraft engines. The company has been at the forefront of efforts to reduce the impact on climate change by providing the most environmentally-responsible products that reduce GHG emissions worldwide. Forover two decades, the company has made significant investments in technologies like the geared turbofan and its technology for advanced low nitrogen oxide (TALON) family of combustors. The company is developing next-generation propulsion systems and technologies that provide avenues for fuel efficiency, lower emissions and noise reduction.