ABSTRACT
The Intergovernmental panel on Climate Change has sounded its alarm through its special report on the impact of global warming of 1.5oC and called for a strengthened global response to the threat of climate change. Despite that the COVID-19 pandemic has left a devastating effect on the aviation industry, this is forecasted to bounce back and recover within a few years. It is therefore important now to revisit opportunities for a better balance between social, environmental and economic impact of the sector. The European Union has been leading the way in limiting the environmental impacts of aviation. Despite that most of the R&D effort has been focused on the airborne phase, the European Union is legislating so that all aircraft movements on the ground are set to be emission-free by 2050. The paper focuses on engineless aircraft taxiing with the aim to reduce emissions on the ground. We demonstrate that upon landing, an aircraft has enough kinetic energy, which if recovered could power a 5-minute engineless taxiing process. When scaled to a large fleet such as low-cost carriers, this emissions problem can be turned on its head and becomes an opportunity for fuel savings and a reduction in emissions on the ground. The paper also demonstrates that the cost to retrofit such technology can be recovered in a short timeframe and therefore there is an economic incentive to the airline. © 2022 ICAS. All Rights Reserved.
ABSTRACT
Airport emissions have received increased attention because of their impact on atmospheric chemical processes, the microphysical properties of aerosols, and human health. At present, the assessment methods for airport pollution emission mainly involve the use of the aircraft emission database established by the International Civil Aviation Organization, but the emission behavior of an engine installed on an aircraft may differ from that of an engine operated in a testbed. In this study, we describe the development of a long-path differential optical absorption spectroscopy (LP-DOAS) instrument for measuring aircraft emissions at an airport. From 15 October to 23 October 2019, a measurement campaign using the LP-DOAS instrument was conducted at Hefei Xinqiao International Airport to investigate the regional concentrations of various trace gases in the airport’s northern area and the variation characteristics of the gas concentrations during an aircraft’s taxiing and take-off phases. The measured light path of the LP-DOAS passed through the aircraft taxiway and the take-off runway concurrently. The aircraft’s take-off produced the maximum peak in NO2 average concentrations of approximately 25 ppbV and SO2 average concentrations of approximately 8 ppbV in measured area. Owing to the airport’s open space, the pollution concentrations decreased rapidly, the overall levels of NO2 and SO2 concentrations in the airport area were very low, and the maximum hourly average NO2 and SO2 concentrations during the observation period were better than the Class 1 ambient air quality standards in China. Additionally, we discovered that the NO2 and SO2 emissions from the Boeing 737–800 aircraft monitored in this experiment were weakly and positively related to the age of the aircraft. This measurement established the security, feasibility, fast and non-contact of the developed LP-DOAS instrument for monitoring airport regional concentrations as well as NO2 and SO2 aircraft emissions during routine airport operations without interfering with the normal operation of the airport.
ABSTRACT
The increasing attention of opinion towards climate change has prompted public authorities to provide plans for the containment of emissions to reduce the environmental impact of human activities. The transport sector is one of the main ones responsible for greenhouse emissions and is under investigation to counter its burdens. Therefore, it is essential to identify a strategy that allows for reducing the environmental impact produced by aircraft on the landing and take-off cycle and its operating costs. In this study, four different taxiing strategies are implemented in an existing Italian airport. The results show advantageous scenarios through single-engine taxiing, reduced taxi time through improved surface traffic management, and onboard systems. On the other hand, operating towing solutions with internal combustion cause excessive production of pollutants, especially HC, CO, NOX, and particulate matter. Finally, towing with an electrically powered external vehicle provides good results for pollutants and the maximum reduction in fuel consumption, but it implies externalities on taxiing time. Compared to the current conditions, the best solutions ensure significant reductions in pollutants throughout the landing and take-off cycle (−3.2% for NOx and −44.2% for HC) and economic savings (−13.4% of fuel consumption).