Fuel burn rates of commercial passenger aircraft: variations by seat configuration and stage distance

Aircraft fuel consumption is a very large component of airline costs. Fuel burn is also very important because it is highly correlated with emissions and contributes directly to transport externalities. This paper calibrates fuel burn in kilos per seat per nautical mile for aircraft using the EMEP/EEA aircraft inventory database. We then employ the model with OAG flight schedule data to evaluate fuel burn by flight routes and aircraft types at a global scale. The paper shows comparative fuel use among different distance based markets as well as among a variety of routes in the long-haul market. The results show geographical heterogeneity of fuel burn rates among a variety of routes, while controlling for seat configuration and stage distance. The paper finds that stage lengths centered on 1500–2000 NM have the lowest fuel burn rates under current technology, fleet composition, and seat configuration. These findings, together with comments on the viability of long range flights provide better understandings not only for the carbon taxation debates but also for operational efficiency of current aviation markets. The lower rates for moderate distance flights seems to favor networks without extreme links, and supports the use of a hub connection scheme.     

An analysis of the greenhouse gas emissions profile of airlines flying the Australian international market

International commercial flights (with the exception of flights between countries in European Union including Iceland, Norway and Liechtenstein) are currently not subject to greenhouse gas emission reduction regulation. To formulate effective and efficiency policy to manage greenhouse gas emissions from air transport, policy makers need to determine the emissions profiles of all airlines currently flying into their country or region. In this paper, we use 2012 data on airlines' aircraft characteristics, passenger load and cargo load (obtained from statistics reported by Australian Government Bureau of Infrastructure, Transport and Regional Economics) to estimate the volume and carbon efficiency on each international route flying to and from Australia. This is the first study to use actual passenger and cargo load data to determine the greenhouse gas (specifically CO₂) efficiency of airlines operating in the Australian international aviation market. Airlines' CO₂ emission profile is dependent on many factors including but not limited to the aircraft used, payload, route taken, weather conditions. Our results reveal that the airlines’ CO₂ emission profile is not only dependent on the aircraft used and the number of passengers but also the amount of cargo on each flight.     

Airline fuel usage and carbon emissions: Determining factors

Using annual data on individual US airlines over the 1995–2015 period, this paper presents regression results relating an airline's total fuel usage to seven variables: the available ton miles of capacity (passengers plus freight and mail) provided by the airline; the average seat capacity of its aircraft, average stage length (flight distance); average load factor (measured by weight); the average vintage (construction year) of its aircraft; the percentage of the airline's flights that are delayed; and the average annual fuel price. The results show how fuel usage and carbon emissions depend on a small set of crucial variables. The estimated fuel-price effect allows the emissions impact of an optimal emissions charge to be computed, and the estimated delay effect shows the emissions impact of an industry-wide reduction in flight delays. The regression model is generated from a theoretical framework.     

Where does flygskam come from? The role of citizens’ lack of knowledge of the environmental impact of air transport in explaining the development of flight shame

A growing number of citizens are concerned about the environmental impact of air transport, and aviation has become synonymous with high carbon emissions and global warming, which has led to the development of flygskam (or flight shame) in Europe. While its impact on air traffic remains unclear, flight shame has forced the airline industry to react and better understand its origin. In this research, building on the growing literature on industry and organizational stigma, we assume that flight shame can be partly explained by a distorted public perception of the environmental impact of air transport. Accordingly, we investigate the level of knowledge of the environmental footprint of air transport. Based on a sample of 1018 French respondents, we reveal that more than 90% of respondents overestimate the share of air transport in global carbon emissions. We also show that 98% of the respondents underestimate the reduction in carbon emissions per passenger. Finally, we investigate the awareness of the measures taken by the industry to curb its carbon emissions and highlight, for instance, that 70% of respondents overestimate the fuel consumption of the newest generations of aircraft. Based on these results, we draw lessons for airlines and for the air transport industry to help cope with flight shame in Europe.     

From passenger growth to aircraft movements

Airlines are able to deal with passenger growth by either increasing the frequency or the aircraft size, which may entail different numbers of aircraft movements. Forecasting the latter is necessary for evaluating technologies, approaching future emissions or anticipating capacity constraints. Purpose of this paper is to forecast a typical fleet mix and the growth of aircraft movements on flight segments worldwide based on an assumed passenger growth. The methodology is implemented in a model called Forecast of Aircraft Movements. Basic approach is the assignment of each flight segment worldwide to a distance, passenger number and aircraft category. For each combination of distance and passenger numbers a typical fleet mix is defined. The forecasted worldwide growth of passenger demand and the empirically determined fleet mix is applied to all segments in order to derive a future scenario. Assuming a certain seat load factor, the frequency growth can be deduced from the aircraft movements generated for all segments. The paper includes a forecast for aircraft movements in a future scenario based on real schedule and passenger data and gives a detailed overview of the methodology and results considering airlines' behaviour.     

Analysis of greenhouse gas emissions of freight transport sector in China

Due to the increasing commercial activities in China, the rapid growth of energy consumption and greenhouse gas (GHG) emissions in the freight transport sector has alarmed the Chinese central government. However, there is a lack of standard measure for evaluating GHG emissions generated from freight transport operations. To improve this situation, Chinese policy makers need to evaluate GHG emissions for energy saving and pollution reduction. This background leads us to examine the GHG emission trajectories and features of Chinese freight transport patterns in the last decade, i.e. between 2000 and 2011. In this study, we examine different regions’ freight turnover and energy consumption by various transport modes (i.e. railway, highway, waterway, aircraft, and oil pipeline) in China. Our results show that the total amount of GHG emissions caused by the Chinese freight transport sector reached 978 million tons in 2011, indicating an average annual growth of 74 million tons CO₂e for the last decade. Shandong, Anhui, and Henan are the main provinces producing GHG emissions, representing 11.7%, 10.3%, and 10% of total emissions generated from the freight transport sector in China, respectively. This study also compares the regional GHG emissions from different freight transport modes including railway, highway, waterway, air transport, and oil pipeline. Based on the findings, policy implications are provided on how to mitigate freight transport emissions among different Chinese regions.     

The potential for European aviation CO2 emissions reduction through the use of larger jet aircraft

There is increasing pressure to reduce global CO₂ emissions, with aviation targeted as an industry with high future expected growth and limited potential for reduced emissions. In Europe, air transport is likely to be included in the Emissions Trading Scheme from 2012, allowing open trading with other sectors. The proposed scheme may be economically efficient but will it do much towards curbing aviation emissions? A number of papers have looked at the ETS impact on air traffic growth rates, and others have forecast the rate of likely future fuel efficiency gains. This paper examines the potential for greater fuel efficiency through the use of larger aircraft and different patterns of operation. Fuel efficiency was found to be related to aircraft size with more benefit from trading up with short/medium-haul than with long-haul aircraft. This relationship only held for long-haul aircraft if those aircraft with two main decks were removed from the sample (these types showing inherently lower fuel efficiency). Combining these findings with manufacturers' and other forecasts of average aircraft size suggests that less than 1% a year of fuel efficiency gains will be available from this source over the next 20 years.     

The cost of abatement options to reduce carbon emissions from Australian international flights

In 2012, a total of 13.1 million tonnes of carbon dioxide were emitted by 14 airlines while transporting 72 per cent of international passengers into and out of Australia in 2012. With passenger and cargo traffic growing at between five to six per cent annually from 2013 to 2033, acquiring more fuel efficient aircraft to both renew the existing fleet and to service growth has the greatest potential in reducing emissions over the next 20 years. Our analysis shows that implementing carbon dioxide emissions abatement options such as installing light weight seats, iPad electronic flight bags, winglets, washing aircraft engines and reducing the number of engines used during taxiing, all offer net financial savings when considered over 20 years. Acquiring new fuel efficient aircraft has the biggest impact on emissions reduction. Low interest loans and longer loan repayment periods may incentivise airlines to acquire more fuel efficient aircraft to service traffic growth but other complimentary incentives and penalties are required to influence airlines to replace their current fleet with more fuel efficient aircraft.     

Exogenous shocks and managerial preparedness: A study of U.S. airlines’ environmental scanning before the onset of the COVID-19 pandemic

Managerial preparedness is a constant concern for firm stakeholders. This concern is exacerbated during times of immense stress brought about by exogenous shocks. In this paper, we analyze the preparedness of U.S. commercial airline management teams to the largest systematic exogenous shock to date, namely the COVID-19 pandemic in 2019 and 2020. We do this by underpinning the paper with theory on environmental scanning and managerial dysfunction and then documenting the signals and actions of management around multiple public health scares. These include the SARS outbreak, the Swine Flu outbreak and the COVID-19 outbreak. Our results, based off of corporate filings with the SEC, is that airline management had multiple “dry runs” before the COVID-19 outbreak that should have lead them to prepare for financially catastrophic scenarios such as the one observed in 2020. Instead, management teams failed to learn from these, and other, prior shocks. Instead, they focused on other, less serious threats while diffusing their financial buffers through dividends and share buybacks.     

The effect of flight distance on fuel mileage and CO2 per passenger kilometer

In this study, the effect of distance on fuel mileage (fuel burn per nautical mile) and CO₂ intensity, based on a large amount of actual flight data, is discussed for narrow-body commercial aircraft performing domestic flights for flight distances of between ～200 and ～800 NM, in Turkey. For twenty-nine domestic routes, the average CO₂ intensity is calculated to be 88 gr/pa-km, with an 80% load factor, ranging from between 112 gr/pa-km (207 gr/pa-NM) for the shortest route and 78 gr/pa-km (145 gr/pa-NM) for the longest route. An overall runway-to-runway analysis reveals that the average flight fuel consumption increases by 5.1 kg for each additional nautical mile. The discussion is extended to cover wind effect, through westbound and eastbound flights, on fuel consumption. The average fuel mileage of the eastbound flights, above 30 kft, is found to be 11.2% lower than those for the westbound flights. A sensitivity analysis is also carried out to reveal the effects of three main flight performance parameters, namely, cruise altitude, cruise speed and aircraft mass on the cruise CO₂ intensity.     

Exploring the dynamic impacts of COVID-19 on intercity travel in China

Many studies have explored the effects of transportation and population movement on the spread of pandemics. However, little attention has been paid to the dynamic impact of pandemics on intercity travel and its recovery during a public health event period. Using intercity mobility and COVID-19 pandemic data, this study adopts the gradient boosting decision tree method to explore the dynamic effects of the COVID-19 on intercity travel in China. The influencing factors were classified into daily time-varying factors and time-invariant factors. The results show that China's intercity travel decreased on average by 51.35% from Jan 26 to Apr 7, 2020. Furtherly, the COVID-19 pandemic reduces intercity travel directly and indirectly by influencing industry development and transport connectivity. With the spread of COVID-19 and changes of control measures, the relationship between intercity travel and COVID-19, socio-economic development, transport is not linear. The relationship between intercity travel and secondary industry is illustrated by an inverted U-shaped curve from pre-pandemic to post-pandemic, whereas that with tertiary industry can be explained by a U-shaped curve. Meanwhile, this study highlights the dynamic effect of the COVID-19 on intercity mobility. These implications shed light on policies regarding the control measures during public health events that should include the dynamic impact of pandemics on intercity travel.     

Analysis of the recent evolution of commercial air traffic CO2 emissions and fleet utilization in the six largest national markets of the European Union

This paper presents the results of a study performed to analyze the evolution of commercial air traffic and CO₂ emissions in the European Union, from 2010 to 2013. Data sources are the European Commission's Eurostat Air Transport Statistics (Eurostat) and EUROCONTROL flight plans database. The changes in the fuel efficiency are analyzed and the potential reasons for those changes investigated. The evolution in the airline fleet composition during the last decade is presented as one of the reasons for the improvement in fuel efficiency, measured in burnt fuel per total Revenue Tonne Kilometre (RTK), as well as the different parameters depending on the airline business model (network carriers, low cost companies, etc.) and the aircraft type.Results show a slight reduction in the traffic, both for passengers and cargo (about −0.8%), and a more important reduction in CO₂ emissions (−4.3%), thanks to an improvement in the fuel efficiency parameter (−3.5%) for the three years period. There has been a relevant change in the fleet composition in the last ten years, with the replacement of older models for more efficient ones, and a shift to larger aircraft, particularly in the regional segment. Traffic has decreased in shorter distances (internal EU traffic), but increased in more efficient long range flights (extra-EU traffic), resulting also in an improvement of the efficiency parameter as average aircraft size and stage length increases.     

Investigations on the distribution of air transport traffic and CO2 emissions within the European Union

This study analyses the structure of air traffic and its distribution among the different countries in the European Union, as well as traffic with an origin or destination in non-EU countries. Data sources are Eurostat statistics and actual flight information from EUROCONTROL. Relevant variables such as the number of flights, passengers or cargo tonnes and production indicators (RPKs) are used together with fuel consumption and CO₂ emissions data. The segmentation of air traffic in terms of distance permits an assessment of air transport competition with surface transport modes.The results show a clear concentration of traffic in the five larger countries (France, Germany, Italy, Spain and UK), in terms of RPKs. In terms of distance the segment between 500 and 1000 km in the EU, has more flights, passengers, RTKs and CO₂ emissions than larger distances. On the environmental side, the distribution of CO₂ emissions within the EU Member States is presented, together with fuel efficiency parameters. In general, a direct relationship between RPKs and CO₂ emissions is observed for all countries and all distance bands. Consideration is given to the uptake of alternative fuels. Segmenting CO₂ emissions per distance band and aircraft type reveals which flights contribute the most the overall EU CO₂ emissions. Finally, projections for future CO₂ emissions are estimated, according to three different air traffic growth and biofuel introduction scenarios.     

The impact of airport capacity constraints on future growth in the US air transportation system

This paper simulates airline strategic decision making and its impact on passenger demand, flight delays and aircraft emissions. Passenger flows, aircraft operations, flight delays and aircraft emissions are simulated for 22 airports in the US, under three airport capacity scenarios. The simulation results indicate that most system-wide implications for operations and environmental impact seem to be manageable, but local impacts at congested hub airports may be significant. The response of the air transportation system to avoid airports with high delays could significantly impact passenger demand and air traffic for these and directly dependent airports. The simulations also suggest that frequency competition effects could maintain flight frequencies at high levels, preventing a significant shift toward larger aircraft, which would otherwise reduce the impact of the capacity constraints.     

Air carrier's liability for the safety of passengers during COVID-19 pandemic

The paper aims to determine the situations when the air carrier is liable for the transmission of COVID-19 in the course of air transport. It must be emphasized here that the carrier's liability results from bodily injury or death that are caused by an accident on board an aircraft or during the operations of embarking or disembarking. Accordingly, in this paper, we addressed if the transmission of COVID-19 an ‘accident’ within the Conventions' meaning and the period of air carrier's liability for passengers' contraction of COVID-19, taking into consideration the exoneration of air carrier's liability in COVID-19 cases. In addition, this paper will study the scope of the safety measures as required by ICAO to prevent the spread of COVID-19 and therefore protect the passengers' safety. In our opinion, we found that the estimate is left to the judge because the assessment of this matter is based on an objective criterion based on the reasonable person test and the fact of each case.     

A robust mathematical model and heuristic algorithms for integrated aircraft routing and scheduling,with consideration of fleet assignment problem

One of the most important airline's products is to determine the aircraft routing and scheduling and fleet assignment. The key input data of this problem is the traffic forecasting and allocation that forecasts traffic on each flight leg. The complexity of this problem is to define the connecting flights when passengers should change the aircraft to reach the final destination. Moreover, as there exists various types of uncertainties during the flights, finding a solution which is able to absorb these uncertainties is invaluable. In this paper, a new robust mixed integer mathematical model for the integrated aircraft routing and scheduling, with consideration of fleet assignment problem is proposed. Then to find good solutions for large-scale problems in a rational amount of time, a heuristic algorithm based on the Simulated Annealing (SA) is introduced. In addition, some examples are randomly generated and the proposed heuristic algorithm is validated by comparing the results with the optimum solutions. The effects of robust vs non-robust solutions are examined, and finally, a hybrid algorithm is generated which results in more effective solution in comparison with SA, and Particle Swarm Optimization (PSO).     

The future of airports post COVID-19

COVID-19 pandemic has hit most sectors of the world and has led to many industries coming to a standstill. It has led to restrictions of movement and travel ban. As a result of these restrictions, transport sector especially in aviation has impacted badly.With the uncertainty of further impact of the current situation, there is a likelihood of the aviation business rebounding at a slower pace bringing V-shape and U-shape recovery as per analysis of economic impacts on civil aviation by International Civil Aviation Organization (ICAO (2020). Currently, airline capacity is down 70 to 80 percent in April 2020 compared to April 2019, and multiple large airlines have temporarily ceased operations. Largely, almost 60 percent of the global fleet was grounded in early April 2020 as per McKinsey report (Curley et al., 2020).In order to support the sinking capacities and revenues, the International Air Transport Association (IATA) calls on the European governments to provide relief to their airlines to sustain their operations. Furthermore, this document highlights the future of airport and air transport industry based on revenue generation sources, cost control strategies and integration of innovations with respect to variable demand and capacity during and post COVID-19.     

Efficiency evaluation of Brazilian airlines operations considering the Covid-19 outbreak

In this paper we evaluate the operational efficiency of the Brazilian airlines considering the novel coronavirus Covid-19 outbreak. This novel coronavirus was first reported end of 2019 in Wuhan, China, however the powerful contamination spread among people forced the World Health Organization to characterize the Covid-19 as a pandemic in March of 2020. Here we analyze the main Brazilian airlines operations response due to lower demand because Covid-19 outbreak in first quarter of 2020 comparing with first quarter of 2019. The analysis here aims to verify the efficiency of airlines in domestic air transport market in Brazil through Multicriteria Data Envelopment Analysis (MCDEA) model. We used MCDEA to avoid limitations of classical DEA models for the case, especially the numbers of decision units and variable. In this paper we used an improvement of the MCDEA model to seek benchmarks considering a dual model all objective functions of MCDEA. The results highlight the challenges for the airlines, due to flight restriction and demand dropping. And also, the evaluation exposes the different company configuration of aircrafts age and network reconfiguration which was reflected by the efficiency difference on the period. The assessment shows the company with a better mix of aircraft models has a leverage on efficiency response due to unpredictable period as the pandemic Covid-19 outbreak.     

Aircraft selection by applying AHP and TOPSIS in interval type-2 fuzzy sets

The selection of the appropriate aircraft can bring competitive advantages to airlines, however, there are a number of factors which introduce a degree of uncertainty to the selection process. By removing this uncertainty, airlines can increase their chances of achieving their long-term goals. New Multi-Criteria Decision Making (MCDM) methods provide decision-makers with a satisfactory solution for choosing suitable aircraft. Therefore, we focused on the multi-dimensional evaluation and selection of the most suitable commercial aircraft alternatives by using new MCDM method. This article provides decision support to airline planners on the selection of commercial aircraft under uncertainty. In the study, unlike other studies in the literature on aircraft selection, the model presented here uses an Interval Type-2 Fuzzy Analytical Hierarch Process (IT2FAHP) and Interval Type-2 Fuzzy Technique for Order Preference by Similarity to an Ideal Solution (IT2FTOPSIS) hybrid methods. The proposed model for aircraft selection allows commercial airlines to evaluate the aircraft in terms of specific criteria: economic performance, technical performance, and environmental impact, and, as a result, it helps decision makers select appropriate aircraft in an uncertain environment. In addition to use by commercial airlines, the methods in the study can also be applied to the selection of training aircraft, cargo aircraft and military aircraft. Our findings show that the Airbus A321neo is the most suitable commercial aircraft in terms of technical aspects, economic aspects and environmental aspects for airlines.     

The impact of aircraft takeoff thrust setting on NOX emissions

Reduced thrust takeoff has the potential to reduce aircraft-related NO_X emissions at airports, however this remains to be investigated using flight data. This paper analyses the effect of takeoff roll thrust setting variability on the magnitude and spatial distribution of NO_X emissions using high-resolution data records for 497 Airbus A319 activities at London Heathrow. Thrust setting varies between 67 and 97% of maximum, and aircraft operating in the bottom 10th percentile emit on average 514 g less NO_X per takeoff roll (32% reduction) than the top 10th percentile, however this is dependent on takeoff roll duration. Spatial analysis suggests that peak NO_X emissions, corresponding to the start of the takeoff roll, can be reduced by up to 25% by adopting reduced thrust takeoff activities. Furthermore, the length of the emission source also decreases. Consequently, the use of reduced thrust takeoff may enable improved local air quality at airports.