Furthermore, if new technology is introduced, then every single current aircraft will have to be retrofitted with the technology, and the technology will have to be implemented on all future aircrafts as well. Therefore, for the purpose of this project, the team is only concentrating on operational changes for flight paths. However, for the sake of completion, other mitigation options are also briefly discussed. 1.7.1 Operational Changes As emphasized earlier, this study will solely concentrate on operational changes to reduce persistent contrail formation. Operational changes include changes to the actual flight path of the aircraft to avoid regions that are highly likely to produce contrails. As described in the graphic below, there are two major types of aircraft maneuvering- tactical and strategic. Tactical maneuvering occurs when pilots request permission from air traffic controllers, while en-route, to make changes to their flight plan. Strategic maneuvering involves filing a flight plan prior to departure to accommodate for regions that the aircraft may want to avoid. This type of maneuvering reduces the cognitive work load on air traffic controllers because they do not have to evaluate whether permission should be granted to an aircraft to make maneuvers while also remaining attentive to other air traffic in the area. 1.7.2 Jet Fuel Additives The formation of contrails occurs when hot engine exhaust mixes with ambient temperature and humidity. As aforementioned, the decomposition of jet emissions consist of carbon dioxide (CO2), nitrogen oxides (NOx), sulfur oxide (SO2), soot, and water particle (H2O). At cruising altitudes, the exhaust mixture freezes and forms ice particles upon contact with the surrounding air. This leads to the formation of visible contrails. The number of ice particles formed in contrails and their climate impact may be reduced by lowering soot emissions and sulfur content of aviation fuels, but the efficiency of such a measure has not yet been quantified [4]. The jet fuel additives provides the optimal ratio of Sulfur (S) content mixture within jet fuel (CnHm+S) during the jet fuel combustion in order to product an ideal combustion that will reduce contrail formation. The following figure shows the number of soot and ice particle per kg of fuel in contrails versus fuel sulfur content (FSC) behind the following aircraft: ATTAS (black squares), B737
Furthermore, if new technology is introduced, then every single current aircraft will have to be retrofitted with the technology, and the technology will have to be implemented on all future aircrafts as well. Therefore, for the purpose of this project, the team is only concentrating on operational changes for flight paths. However, for the sake of completion, other mitigation options are also briefly discussed. 1.7.1 Operational Changes As emphasized earlier, this study will solely concentrate on operational changes to reduce persistent contrail formation. Operational changes include changes to the actual flight path of the aircraft to avoid regions that are highly likely to produce contrails. As described in the graphic below, there are two major types of aircraft maneuvering- tactical and strategic. Tactical maneuvering occurs when pilots request permission from air traffic controllers, while en-route, to make changes to their flight plan. Strategic maneuvering involves filing a flight plan prior to departure to accommodate for regions that the aircraft may want to avoid. This type of maneuvering reduces the cognitive work load on air traffic controllers because they do not have to evaluate whether permission should be granted to an aircraft to make maneuvers while also remaining attentive to other air traffic in the area. 1.7.2 Jet Fuel Additives The formation of contrails occurs when hot engine exhaust mixes with ambient temperature and humidity. As aforementioned, the decomposition of jet emissions consist of carbon dioxide (CO2), nitrogen oxides (NOx), sulfur oxide (SO2), soot, and water particle (H2O). At cruising altitudes, the exhaust mixture freezes and forms ice particles upon contact with the surrounding air. This leads to the formation of visible contrails. The number of ice particles formed in contrails and their climate impact may be reduced by lowering soot emissions and sulfur content of aviation fuels, but the efficiency of such a measure has not yet been quantified [4]. The jet fuel additives provides the optimal ratio of Sulfur (S) content mixture within jet fuel (CnHm+S) during the jet fuel combustion in order to product an ideal combustion that will reduce contrail formation. The following figure shows the number of soot and ice particle per kg of fuel in contrails versus fuel sulfur content (FSC) behind the following aircraft: ATTAS (black squares), B737
Contrails_FinalReport.docx