Abstract:

Environmental concerns in aviation have been a widely discussed agenda in many of the international meetings throughout the world in the bilateral or multilateral talks. Emission from aviation currently account for 3.5 % of the total anthropogenic radiates which is anticipated to rise to as much as 15% by 2050, if no further organizational measures are taken to decrease these emissions. Delays caused by congestion in the air traffic at the various airports across the globe are one of the major sources of environmental pollution and also the unnecessary cost to airlines, passengers, and businesses dependent on aviation transportation. Aircraft due to this reason are frequently forced to fly at such a different cruise altitude and/or the cruise speed for which for which they are not designed. This results in unnecessary fuel burn and hence the related gaseous emission which rises environmental concerns both at the local and global levels. This article addresses the role of route optimization in the raised concerns of aircraft emissions and the fuel costs. It outlines the ways it can be addressed at various levels like route optimization at operational level, aircraft designing to suit a particular flying route at manufacturing level and at the level of air traffic management. The accuracy in the flight plan also forms a part of the route optimization programme.

Introduction

The aviation sector in the recent years has witnessed an incredible increase in terms of its size and operations. It has been therefore striving hard to develop resources and means to have consistent, affordable, and environmentally-efficient supplies of energy sources together with an effective and efficient balanced approach to simultaneously address environmental impacts of aviation related to noise, air quality, and climate change in a manner which is reliable and cost-beneficial. However despite the recent instability and volatility being there in this sector, it is expected that this commercial aviation market would recover in no time and would experience a rapid and continued growth. Therefore, the associated impacts of aviation on environment are also set to become a major concern in the near future particularly absence of effective measures aimed at its mitigation. The principal concern in that also is going to be the issues regarding air qualityand climate change and its impact on human health and environment. In the event of the emissions from non-aviation sources decreasing at faster rate, the contribution from aviation sector in terms of emissions of air pollutants may relatively increase and become a major concern.[2]

The process of route optimization in a flight plan not only involves taking into account the correct calculations of aircraft performance and weather conditions, but also includes route restrictions imposed by controllers of air traffic in various air spaces and the other relevant regulatory restrictions.[3] For the calculation of an optimal flight plan and route aimed at cutting fuel costs and emissions includes scheming multiple flight routes or approaches to flight operations for each flight, ranking them in order of the total costs involved, choosing the most cost effective plan and providing summaries of the other scenarios for operational flexibility.[4] The process of route optimization can be challenging as it involves numerous different elements and the best flight route depends on various factors and the actual conditions of each flight. These factors includes the forecast of the upper air currents and temperature, the amount of payload, and the time-based costs on that particular day. The time-based costs are especially dynamic, as they are driven by again different factors which include payload value, schedule and operational limitations for the crew and the airplane.

The delays in the air traffic due to congestion in the airport systems of various nations often results in needless costs to the airlines, passengers and any such business or economic activity dependent on aviation. The probable costs of congestion to the various airline industry, passengers and shippers at various airports are esteemed to be in billions per year.[5] Furthermore this cost can be divided into two sects i.e. costs directly to the airlines and in terms of value of total passenger time. The environmental impacts of such delays are an added concern which seeks immediate attention.

There is an urgent need for a global agreement in the event of increase of aviation emissions. The global emissions by 2020 from aviation are projected to be around 70% higher than in 2005 even if fuel efficiency improves by 2% per year. ICAO forecasts that by 2050 they could grow by a further 300-700%.[6] If the present emissions levels remain unchecked it has been projected that the carbon pollution may get almost triple by 2036 and may increase by four times from 2005 to 2050 as projected by International Civil Aviation Organization (see figure 1).

It has been seen that historically, aircraft designers have been working with the primary objective of maximizing profits for the corporate shareholders.[7] Due to the rising concerns of climate change throughout the various nations, environmental performance has off late become a major designing force for the newer aircrafts. Nowadays the aircrafts are designed for better performance with least carbon and NO_X emissions at a favorable altitude and on a given flight rout. This also brings down the operation and fuel costs.

This article therefore draws on the various factors of route optimization and focuses on different elements like conflicts in air, optimizing payloads, flight operations, air traffic management (ATM), and accuracy of flight plans among others. It also outlines the various levels at which this concern can be addressed for a cost effective flight mitigating the bearing on environment.

The basic understanding of the conflicts in air traffic is that, it means and occurs when two or more aircraft intrude upon the minimum required separation of each other in flight, such separation as defined by the regulator of air traffic. The detection of such conflicts is understood as the identification of probable conflicts that may occur, by predicting the future trajectories the aircrafts in flight based on their current flight plans, position and headings. In the event of detection of a conflict, it is resolved by altering the flight plan of one or more of the aircraft so as to satisfy the minimum separation requirements. Yet, the whole aim is to ensure that there is conflict-free optimal trajectories planned for all the aircrafts which enter or exit a given airspace. For that purpose, a static conflict resolution algorithm is developed which is then used dynamically to create conflict free trajectories and also to resolve the possible conflicts.

The global commercial aviation industry today works with the primary purpose of moving people and goods around the world in a way which is both quick and economical. The aircraft manufacturing industries are in business for making profits for its shareholders by creating produces and services to suit their needs and demands. The national governments worldwide are also a stakeholder in this industry to ensure public safety and for managing the entry and exit of aircrafts in their airspace through various regulations. There have been some government regulations in the past for limiting the air and noise pollution levels in and around the airports. With the growing government concerns anthropogenic climate change today, there is a growing debate on expanding these emission and noise control regulations to cover the complete flight regime by way of enforcing a financial penalty for emissions beyond permitted levels. The real cost of these emissions have not been understood seriously at this time, but is expected to be significant in the coming years. As a result, it is incidental for designers of the aircrafts to consider aircraft emissions and engine performances during the conceptual designing process with a view to understand and convey to the policy makers the tradeoffs between economic performance and environmental performance. The economic performance of the aircraft also  to a greater extent depends on the route network over which the aircraft operates depending on the total emissions that the airfield allows. However, this is mostly dictated to the aircraft designers to suit a given flight route network.

It would be important to discuss here that we are concerned only with the aircraft emissions that have an adverse environmental impact. The most influential of all those emissions are CO2, NO_X and contrail formation. These emissions are directly proportional to the fuel burnt in the aircraft and also depend on the altitudes that they fly or are forced to fly in case of airport congestion or conflicts in airspace. In particular NO_X emissions are related directly to the design of the fuel combustor, engine design, fuel burn, engine cycle and mainly the overall pressure ratio in the fuel burn process. The modeling of the emissions by contrail formation can also be possible, but for that there has to be a good detail of the local atmosphere and the conditions along the various segments of the flight route.

For the purpose of route optimization and therefore aircraft emissions controls there can be resolve at the following levels. The first being the operational level where emissions can be controlled by reducing the fuel usage at the operational level of the aircraft. At the level of airlines it can be mitigated at the level of aircraft designing and manufacturing itself. Finally at the level of air traffic management there can be optimization by providing the aircrafts with an accurate flight plans that can be optimized in route according to the needs of the flight. These optimization at various levels have been discussed at length below.

Operational level – This is the most direct way for an airline to improve on its fuel efficiency. This can be achieved by modernizing their aircraft fleet with those which use the modern technologies and high performance and efficiency engines.

One of the major problems faced by the airports at operational level is the congestion at the airports. The airplanes in that event are often forced to fly at a different cruise altitude and speed for which they are not designed. They are made to stay in flight which also results in unnecessary fuel burns and emissions. It may be noted here that the significant magnitude of the delays in air traffic presently observed, is an indication that the current air traffic control infrastructure is not capable enough to handle the current levels of air traffic. In the light of the forecast that is being projected about the growth in aviation sector over the next decade, there would be an urgent need of air traffic control decision-support systems or such automation tools for addressing the problems of congestion at the various air fields in the world. Additionally it is also required to develop advanced algorithms for air traffic conflict detection and resolution for the overall development of the air traffic management (ATM) system. This is important especially when issues like safety, growing capacity and their environmental implications are considered.

The new technologies for flight operations can be adopted in like manner as were adopted in 1970s for the purpose of flight management system. In that there was a new technology introduced for fuel efficiency, the flight management system used to automatically set the most efficient cruise speed, altitude, engine power based on the fuel availability and other such cost parameters involved.^[8] The other ways to improve on fuel efficiency at operational level is by reducing unnecessary weight, increasing load factors Continuous Descent Approach; restraining from the use of auxiliary power and reduction in the taxiing of the plane at the large airports. It has been projected that such improvements in the air traffic management (ATM) could cause less fuel consumption, increase in efficiency estimated to be in the order of 6 -12 %^[9].

At the level of route optimization- The best route for an aircraft to fly depends on the various factors for each flight. These include the weather forecast, air currents at the upper atmosphere, winds, temperatures the amount of payload and the co0sts based on time for that day. The costs which are time based are especially dynamic as they are determined by the value of the payload and the schedule and operational limitations for the crew and the airplane. Wind speeds also have a significant impact on the selection of the optimal route for the aircraft. Most of the Flight planning systems make use of the wind forecasts from the U.S. National Weather Service and U.K. Meteorological Office, which are regularly updated every one to six hours, so as to include the winds in making the best suited flight plan and calculations for aircrafts. However the routs can be optimized by nearly every flight planning system to calculate best flight routs, many airlines still prefer to use fixed “company routes” most of the time. A possible reason for the limited adoption of the route optimization has been the restrictions placed by Air traffic Control (ATC) organizations, overflight permissions, policies of various companies on the routing of aircrafts in certain airfields. For developing an effective flight planning system, there is need to have algorithms which contains models of all these restrictions. These models are then applied together with all the information such as wind condition, temperature, payload and other costs while still obeying with all restrictions.

Airlines– In recent times, airlines around the globe have carried out a range of procedures at operational, maintenance and flight planning levels to ensure that their current fleet of aircrafts flies at optimum efficiency levels. These measures range from reducing the weight of crockery on flight to washing their flight’s engine. For example an airline introduced a new cart for beverages on flight the weight of which was reduced by almost 9 Kgs. than the earlier model and the savings out of it is expected to be around $500,000 in annual fuel costs across the fleet.

Several other measures like reducing the weight of the passenger seats, removing electrical appliances to minimum needs like ovens for serving hot meals on selected flights, replacing hard cabin divides with curtains, using carbon fiber seats instead of aluminum alloys etc. are just some of the ways to reduce unnecessary weight on aircrafts to increase fuel efficiency. All these measures put together can save a lot of fuel in flight over the time. Another example of such initiative is a successful airline initiative to save weight by matching the quantity of drinking water with the number of passengers on board in a more calculated way, instead of filling the water tanks completely for each flight.^[10] The fuel consumptions can also be reduced by the routinely inspection of the aircraft during systematic maintenance checks for the identification of the possible defects like damaged seals, chipped metal, paints, this can lower the fuel consumption annually by as much as 0.5%.^[11]

In India, the operators are being advised on improvement in fuel efficiency in their respective fleet. The operators have already started to reduce fuel consumption by adopting better operational procedures such as minimum usage of APU, reduced flap takeoff and landings, idle reverse on landing, proper flight planning system, adhering to proper maintenance of aircraft, weight reductions in the form of reducing the weight of cabin equipment, catering services, avoiding carrying extra fuel on board, etc^[12]. IATA estimates that within India, a streamlined ATM system can cut airlines’ fuel bills and thus emissions by more than 50 %^[13].

Air Traffic Management– One of the key methods to save on fuel during flight operations is modern approach for flight descent known as Continuous descent operations (CDO) in which an aircraft descends from its cruise height towards the airport in a continuous approach with minimum thrust. In earlier approaches the aircrafts went through a conventional series of stepped descents requiring the pilot to increase engine thrust to maintain level flight. This new technique helps in saving on a lot of fuel and up to 40 % less fuel is used in the course of approach phases if CDO is adopted. Additionally, there is also a significant reduction in noise footprints together with a remarkable 25-40 % less consumption of fuel through the final 45km of the flight.^[14]

Usually an aircraft flight is divided into two cycles; first Landing and take-off cycle — LTO and second Climb, cruise and descent cycle — CCD. Looking at the rate of fuel burn in these cycles separately, the proportion of fuel burnt in both the cycles varies depending on the flight operations. Particularly the contribution from short haul flights is more in LTO as compared to long haul flights.^[15] For example, the assessments of Airbus A340 and Boeing 747 average emissions has shown the fuel consumption by long haul flights are comparatively less for LTO operations.[16] As the fuel consumptions in LTO is fixed, it can be concluded that long haul flights are more efficient than short haul ones.

The emission modeling is generally done on the basis of carbon footprints per passenger kilometer basis. It has been found that the carbon efficiency of the short distance flight is comparatively lower that long haul flights if we generally look at the carbon dioxide per emissions per seat per kilometer. As the fuel consumption is highest in landing and take-off cycles and therefore it forms the major part of the emissions. In the case of larger aircrafts in medium or long haul flights the climb, cruise and descent cycle forms the major part of the fuel burn and the LTO is not that significant. However the flight efficiency tends to decrease slightly with an increase of the distance owing to the larger amount of fuel that has to be carried for long distances.^[17]

Taking into consideration other non-CO2 emissions, one of the key methods which has been adopted internationally involves the Air Traffic Management (ATM) aimed at decreasing inefficiencies in flight patterns and encouraging the flight patterns that take into consideration the atmospheric condition that prevails in flight route.^[18] By the use of futuristic ATM measures like continuous descent operations (CDO), Controlled Time Arrival (CTA) and System wide information management system (SWIM) can significantly reduce the emissions by efficiently managing the air traffic, they have already been proposed for adoption by airlines worldwide.^[19]

In another measure to cut down on the fuel burns, the airports have been providing direct electricity to the aircrafts in place of using their auxiliary power unit. As in the aircrafts, there is such an auxiliary power unit (APU) in the form of a generator, which provides power to the aircraft when the main engines are turned off for the purpose of lightening air conditioning and such other needs when parked at the airport gate. Many of the airports by providing direct electricity connection to the aircrafts have reduced the need for switching to APU.  There is also research being done to introduce the use of power generated by fuel cells to replace the APUs. These cells could reduce carbon emissions by over 6,000 tonnes per aircraft over its operational life.^[20]

In India, the new airports are being designed on Green Building Codes to reduce their carbon footprint. More emphasis has been laid on encouraging them to use clean and renewable sources for their needs by making use of solar panels, waste management plants, waste water treatment and rain water harvesting systems. They are also being encouraged to use Compressed Natural Gas (CNG) operated vehicles inside and in the vicinity of the airport for reducing emissions.^[21]

The air navigation service providers (ANS) are also implementing Performance Based Navigation (PBN) procedures for optimizing the utilization of airspace and enhancing the capacity of the airports by taking benefit of airborne capabilities and Global Navigation Satellite Systems (GNSS). For providing sustained and cost effective benefits to the stakeholders in terms of fuel savings, emission reductions capacity enhancement and improved airport access, PBN Implementation Roadmap of India has been established with a view to have a sustained effort in implementing PBN procedures at all airports and airspace in India.^[22]

The importance of accuracy in flight plans.

Fuel consumption and costs can be greatly reduced also by improving on the flight plans in terms of their accuracy. This means having accurate flight plans and having a calculated plan for integration with other systems and data systems through accurate engineering and information. The flights can make use of the accurate fuel requirements so as to avoid carrying extra fuel by carrying just the fuel they need to complete the flight. For that there has to regular inputs of flight information, weather conditions together with calculated and accurate algorithms and advanced engineering to select the best flight plans, routs, requirements and to integrate with systems both inside and outside the aircraft.

For example, the performance and characteristics of the airplane are directly determined by the manufacturer data of the plane. But they must be modified installing master equpments, configurations to suit the specific needs of the flight route, flight operations.  There can be deviations from such base line data available from Boeing Airplane Performance Monitoring software. There also has to be an up to date payload predictions and information inputs and it needs to be integrated with the reservation systems to make accurate predictions. Such time-based cost effective prediction turns out to be most accurate when it is integrated with operational control and crew tracking systems. Integration with weather information systems and prediction systems for possible delays or deviations are much needed for an accurate flight plan rather than having rough guesses. The integration of well-tuned planning and information systems with the calculation of the flight plan helps in achieving the highest level of accuracy. That makes the flight crew in making more precise calculations in using the extra fuel that might be needed. That in turn has its effect on emissions as the longer the aircraft stays in the air with extra load and fuel in adverse weather conditions, the more will be the fuel urns and emissions.

Existing roadmaps

The high-level meeting on International Aviation and Climate Change, 2009 agreed on the following measures to reduce carbon emissions (CO₂) from the aviation sector^[23]:

1. a global goal of 2 % annual improvement in fuel efficiency until the year 2050, and further exploration of the feasibility of more ambitious medium and long-term goals, including carbon-neutral growth and emissions reductions;
2. development of a global CO₂ Standard for aircraft and facilitation of further operational changes to reduce aviation emissions;
3. development of a framework for market-based measures in international aviation;
4. further elaboration on measures to assist developing States and to facilitate access to financial resources, technology transfer and capacity building; and
5. submission of States’ action plans, outlining their policies and actions, and annual reporting of data to ICAO on their aviation fuel consumption.

International Civil Aviation Organization (ICAO) is the principal organization that requires the airlines to adhere to the environmental certification standards adopted by its Council. It promotes the safe and orderly development of the international civil aviation and its standards and regulations throughout the world  The ICAO Council’s Committee on Aviation Environmental Protection (CAEP) conducts the majority of ICAO’s environmental technical work and has worked to develop a range of Standards to address aircraft noise, aircraft emissions and local air quality. These rules and standards are contained in Annex 16 (Environmental Protection) to the Convention on International Civil Aviation. The Annexure presently has two volumes outlining separate standards for aircraft noise and aircraft engine emissions respectively. These regulations have been framed keeping in mind the environmental impact of aviation in the vicinity of the airports and also the society at large and are regularly updated by the organization through regular international meetings .

Currently the CAEP is working on the development of an Aircraft Carbon Dioxide (CO₂) Emissions Standard which was initiated as a result of the recommendation by ICAO Programme of Action on International Aviation and Climate Change. The programme forms a part of a set of measures which have been undertaken to reduce greenhouse gas emissions caused by the aircraft emissions. Afterwards the 37th Assembly (Resolution A37-19) adopted in October 2010, requested the CAEP to develop a standard for aircraft emissions to be known as ICAO CO2 Emissions Standard.[24]

In a recent step by the ICAO under the Committee on Aviation Environmental Protection (CAEP) process, the organization has commenced an effort to establish environmental objectives, medium and long term in nature relating to three types of technologies in the area of noise, NOx emissions and fuel burns. Additionally the segment of the expected impacts of such long and medium term measures for the improvements in emissions and noise control is also underway. This whole process is being led by panel of independent experts from across the globe to ensure transparency and involvement of all stakeholders in aviation industry. The aim of the whole process is to set goals so as to provide the R&D industries with a reasonable stretch working in cooperation with states to meet the set targets.[25]

A breakthrough in CO₂ emissions was achieved with the establishment of the worldwide Aircraft CO2 emissions Standard in the wake of CAEP reaching a unanimous agreement for the reinforcement of CO₂ standards. The emission standard was reached on 11 July 2012. It came out with a CO₂ metric system for emissions which represents the CO₂ emissions produced by the aircraft. The emission system is intended to rightfully reward advancements in aircraft technologies (i.e. structural, propulsion and aerodynamic) which results in the reduction of CO₂ emissions at the different stages of the flight. The emissions standard adopted thus accommodates full range of technological advancements which can be employed by the manufacturers to reduce the CO₂ emissions. The CO₂ metric system is based on three fundamentals associated with the aircraft technology and design: these are namely cruise point fuel burn performance; aircraft size; and Aircraft weight.

The CAEP after the implementation of this decision on CO₂ metric system plans to move to the next phases of developing the ICAO CO₂ emission standards. The further stages include defining the procedures for certification for each of the factors in the metric system agreed by the nations together with the determination of the applicability of the new standards. After that the next stage is the framing of the regulatory limits of CO₂ emissions using the standards of ICAO for technical feasibility, benefits to the environment, cost effectiveness, and its impact on the interdependent stakeholders. After the completion of these steps, the new standards for the CO₂ emissions will then go through the formal review process and the approval by the relevant bodies of ICAO and the member states which will then be followed by the incorporation of the same into the national regulatory frameworks of the nations. The official approval for the same is expected next year.[26]

Besides these there have been many research projects which have been in place for improving the fuel efficiency in the aviation sector. Some of the most promising initiatives are Clean Sky Joint Technology Initiative (JTI), US Federal Aviation Administration (FAA) CLEEN programme, Single European Sky ATM Research (SESAR), Atlantic Interoperability Initiative to Reduce Emissions (AIRE) and NASA Environmentally Responsible Aviation Program.[27]

In addition to the technological advancements and the designs of the aircrafts a key are of improvement is also the optimization of the air space which again includes route optimization and aircraft operations. For this, three major Air Transport Management services have been recognized internationally,^[28] developing a single sky system for Europe, an efficient Pearl River Delta in China; and a Next Generation Air Traffic System in the US.[29]

To make the European sky more manageable and efficient for reduced carbon emissions, there might be a need to regulate it under a single sky zone. The EU airspace which is split in 36 different zones for flight control, it has been planned that they will be merged into 15 larger zones in stages to be known as ‘functional airspace blocks’, or FABs. The next step will be to amalgamate these zones into a single European sky. The European Union has also been working on reducing the need to take longer routes due to military no fly zones which restrict the operation of civilian and commercial flights over that airspace.^[30]

The EU starting January 1, 2012, restricted the entry of the airlines to those who chose to join the EU emission trading scheme. Though the program generated a stiff opposition from many airlines and countries, it is aimed at spurring the airlines to invest in solutions aimed at deploying new aircraft and flight plan technologies reducing pollution from this growing source.

In Asia Pacific skies, there was a multilateral partnership established in 2008 of the air navigation system service providers known as the Asia Pacific Initiative to Reduce Emissions (ASPIRE). Presently this partnership is formed between the air navigation service providers from Australia, New Zealand, USA, Japan and Singapore, although also airlines and other industry stakeholders are associated to specific initiatives. ASPIRE aims to exchange ideas and collaborate on environmentally-friendly operational procedures, standards and best practices.^[31]

Presently the airspace in India comprises of nearly three million square meters and is divided into five flight information regions (FIRs): Mumbai, Kolkata, Delhi, Chennai, and Guwahati (a sub-FIR).[32] Currently, 14 monopulse secondary surveillance radars (MSSRs) providing en route coverage, 8 Terminal Area Radars (TARs) and 11 Area Control Centers (ACCs). There are 12 neighboring FIRs that share common Indian FIRs: Pakistan, Oman, Yemen, Mogadishu, Seychelles, Mauritius, Male, Sri Lanka, Malaysia, Myanmar, Bangladesh, and Nepal. Vertical segmentation of air space into lower, middle, upper, and super-high sectors in the airspace for efficient management and safe operations practiced in other countries have not been implemented in India yet^[33].

For the improvement of air traffic management and the resulting CO2 emission therefore, Future Indian Air Navigation System (FIANS) Master Plan has been developed which is based on the estimated growth in air traffic. For the optimum utilization of the airspace for the operations worldwide, the plan supports the requirements of cross border operations and standards as well as developing performance based operations. The main areas of focus for the implementation of an effective plan for CO2 reduction are use of digital communication; satellite- based navigation supplemented by GPS Aided Geo Augmented Navigation (GAGAN); secondary surveillance radars (SSR), ATM Automation and consolidation of 11 Area Control Centers (ACCs) into four Centers initially and two Centers in the long term; and implementing integrated weather information system.[34] In addition to this GAGAN, the (Indian Space Research Organization) ISRO is implementing an Indian Navigation Regional Satellite System (INRSS), an independent, even satellite constellation built and operated by India aimed at maintaining operations between other regional augmentations to GPS for global navigation.^[35]

Conclusion

To conclude it can be inferred from the present circumstances that there is an utter need for a reliable, affordable, and environmentally-efficient energy supply in aviation industry. Equally important is to develop an effective and stable approach to concurrently address environmental issues related to noise, air quality, and climate change impacts in a manner which is cost-beneficial and considering potential tradeoffs in order to support continued growth. Regardless of the recent instability, it is expected that the commercial aviation market shall recover with time and is expected to grow steadily. Consequently it is expected that the environmental impacts of the same shall increase in the absence of the potential effective measures for its mitigation and control.

Millions of gallons of fuel can be saved by the airlines every year by having accurate, optimized flight plans without the need of forcing the airlines to change or compromise on their schedules or service. Such benefits can be realized by the airlines by investing in a high-end system for flight planning with cutting-edge optimization capabilities along with ensuring their precision by making a comparison of the flight plan values to the actual flight data. In this process there has to be the identification of the cause of such inconsistencies, and then use this information to update the parameters used for the calculations in making flight plans. It has to be ensured that the flight planning systems take full advantage of the air traffic and of airspace and air traffic management liberalization by working together with other airlines and operations to develop the best possible ways to resolve the aviation conflicts.

References

• R. Deehan. Remarks. Greater Miami Chamber of Commerce Transportation Summit Miami, Florida, November 29, 2006
• Yenneti K and Joshi G 2010, Chapter 18: Carbon Dioxide Emission Reduction Potential from Civil Aviation Sector — A Case Study of Delhi-Mumbai Air Route in the India Infrastructure Report 2010
• Steve Altus, Effective flight plans can help airlines economize, Aero Quarterly, QTR 03|09.
• Aircraft CO2 emissions standard metric system, ICAO fact sheet, available at https://www.icao.int/environmental-protection/Documents/CO2%20Metric%20System%20-%20Information%20Sheet.pdf
• India’s Aviation Industry: An Overview by The MITRE Corporation/CAASD, 2009
• Arushi, Stefan Drews, Aviation and Environment, A Working Paper, Centre for Science and Environment, June 2011.
• Fuel saving – contributing to a sustainable air transport development, ATR Customer Services, January 2011
• ICAO Environmental Report 2010, Aviation and Climate Change, available at www.icao.int/environmental…/ENV_Report_2010.pdf.
• Air Transport Action Group (ATAG) 2010, Beginner’s Guide to Aviation Efficiency www.enviro.aero.
• ICAO, 2009, Measures Adopted by Civil Aviation Sector in India presented at High-Level Meeting on International Aviation and Climate Change, Montreal
• Lan, S., J.P. Clarke, C. Barnhart. 2006. Planning for robust airline operations: Optimizing aircraft routings and flight departure times to minimize passenger disruptions. Transportation Science 40(1) 15–28.

 

 

 

Annexure

Figure 1: total global aircraft NO_X below 3000 feet, (915 meters) AGL

Source: ICAO Environmental report 2010

Figure 2: Total aircraft fuel burn, 2006 to 2050.

Source: ICAO Environmental report 2010

Figure 3: Commercial aircraft fuel efficiency (CASFE) Fuel-Flight results

Source: ICAO Environmental report 2010

[1] Assistant Professor, MATS Law School, MATS University, Raipur, C.G.

[2] Committee on aviation environmental protection (CAEP) eighth meeting, Agenda Item 5: Future work , update on U.S. aviation environmental research and development efforts,  Montréal, 1 to 12 February 2010.

[3] Fuel saving – contributing to a sustainable air transport development, ATR Customer Services, January 2011

[4]Steve Altus, Effective flight plans can help airlines economize, Aero quarterly, qtr_03 | 2009, p 27-30, available at www.boeing.com/commercial/aeromagazine.

[5] R. Deehan. Remarks. Greater Miami Chamber of Commerce Transportation Summit Miami, Florida, November

29, 2006

[6] Reducing emissions from the aviation sector, available at https://ec.europa.eu/clima/policies/transport/aviation/index_en.htm

[7]Marla, L., C. Barnhart. 2010. Robust optimization: Lessons learned from aircraft routing. Working Paper, available at www.agifors.org/award/…/LavanyaMarla_paper.pdf.

^[8]  Air Transport Action Group (ATAG) 2010, Beginner’s Guide to Aviation Efficiency www.enviro.aero.

^[9]  Yenneti K and Joshi G 2010, Chapter 18: Carbon Dioxide Emission Reduction Potential from Civil Aviation Sector — A Case Study of Delhi-Mumbai Air Route in the India Infrastructure Report 2010

^[10] Air Transport Action Group (ATAG) 2010, Beginner’s Guide to Aviation Efficiency www.enviro.aero.

^[11] Ibid.

^[12] ICAO, 2009, Measures Adopted by Civil Aviation Sector in India presented at High-Level Meeting on International Aviation and Climate Change, Montreal.

^[13] IATA (2008a). ‘Building a Greener Future’, April, available at https://www.iata.org.

^[14] Air Transport Action Group (ATAG) 2010, Beginner’s Guide to Aviation Efficiency www.enviro.aero.

^[15] Dr Christian N. Jardine 2005, Calculating the Environmental Impact of Aviation emissions, Environmental Change Institute, Oxford University Centre for the Environment

[16] Ibid.

^[17] Ibid.

^[18] Yenneti K and Joshi G 2010, Chapter 18: Carbon Dioxide Emission Reduction Potential from Civil Aviation Sector — A Case Study of Delhi-Mumbai Air Route in the India Infrastructure Report 2010

^[19] Dr. Kota Harinarayana, 2010, Green Aviation presented in February at New Delhi

^[20] Air Transport Action Group (ATAG) 2010, Beginner’s Guide to Aviation Efficiency www.enviro.aero.

^[21] ICAO, 2009, Measures Adopted by Civil Aviation Sector in India presented at High-Level Meeting on International Aviation and Climate Change, Montreal

^[22] Ibid.

^[23] ICAO, 2010, Environmental Report 2010, Chapter 2

[24] Aircraft CO2 emissions standard metric system, ICAO fact sheet, available at https://www.icao.int/environmental-protection/Documents/CO2%20Metric%20System%20-%20Information%20Sheet.pdf

[25] Technology Standards, Certification Standards and Technology Goals, availabl at   https://www.icao.int/environmental-protection/Pages/technology-standards.aspx

[26] Technology Standards, Certification Standards and Technology Goals, availabl at   https://www.icao.int/environmental-protection/Pages/technology-standards.aspx

[27] Arushi, Stefan Drews, Aviation and Environment, A Working Paper, Centre for Science and Environment, June 2011

^[28] IATA 2007, State of the Air Transport Industry—64th Annual General Meeting, Montreal

[29] Ibid.

^[30] Air Transport Action Group (ATAG) 2010, Beginner’s Guide to Aviation Efficiency www.enviro.aero.

[31]www.aspire-green.com

[32]India’s Aviation Industry: An Overview by The MITRE Corporation/CAASD, 2009

^[33] Ibid.

[34] Arushi, Stefan Drews, Aviation and Environment, A Working Paper, Centre for Science and Environment, June 2011

^[35] India’s Aviation Industry: An Overview by The MITRE Corporation/CAASD, 2009