Air traffic management technology and procedures can make a major contribution to the industry’s environmental performance. Emma Kelly reports on some of the initiatives.
Every day over 100,000 flights take off around the world. But up to 8 per cent of aviation fuel used on these flights is estimated to be wasted due to the inefficient routes that aircraft currently have to fly, according to the Air Transport Action Group (ATAG) in its Revolutionising Air Traffic Management report.
The Civil Air Navigation Safety Organisation (CANSO) estimates that on an average global basis, the current air traffic system is only operating at 92 to 94 per cent efficiency. CANSO has set a goal of reaching 95 to 98 per cent efficiency by 2050, with 98 per cent considered to be the limit of possible efficiency.
The global air traffic management (ATM) system will never achieve 100 per cent efficiency, ATAG says, as there will always be elements that get in the way, including weather, closed military airspace and congestion. ATAG also points out that each year growth in air traffic adds to the inefficiency, making gains harder to reach. “If we do nothing, the system is going to become less and less efficient. This is why a revolution in the global air traffic system is needed,” it says.
Improving aviation efficiency is no longer an option but has become an environmental and business necessity, says ATAG, pointing out that fuel accounts for over one-third of an airline’s operational costs and ATM can play an important role in reducing this bill.
The current system dates back to the 1940s and although it has served the industry well, it will continue to struggle to cope with the growth of air transport. As a result, new ATM programmes are under way around the world, with Single European Sky (SES) in Europe, NextGen in the United States and Seamless Asian Sky in the Asia-Pacific region.
Europe’s airspace is currently organised in a highly fragmented way, with nearly 40 different flight control zones and dozens of air navigation service providers (ANSP). The SES was launched in 2004 in an effort to harmonise the fragmented architecture with the aim of improving performance.
By 2020, SES aims to achieve a three-fold increase in ATM capacity where needed; improve safety performance by a factor of 10; reduce by 10 per cent the impact on the environment; and provide ATM services at a unit costs at lest 50 per cent less than current costs.
The current fragmented European system results in an estimated Euros 5 billion additional cost to airspace users per annum, around 100 million hours of delay to passengers and 8.1 million tonnes of additional CO2.
ATAG says the challenges involved are creating a mature performance system with appropriate targets and incentives across the entire ATM supply chain; modernising ATM infrastructure by ensuring key stakeholders synchronise and co-ordinate their efforts from research to industrialisation to deployment; and having the support of policy makers to change the institutional structure of ANSPs through consolidation.
SES research and development initiatives are well under way, notes ATAG, with work co-ordinated through SESAR – SES ATM Research – formed by the European Commission, Eurocontrol and industry.
ATAG says there is still a lack of progress, however, in reforming ANSPs to support the change in structure designed to lead to a truly efficient ATM system. There is also a lack of common understanding among stakeholders on the path required to get to the end goal, ATAG adds. “All parties, including the industry and governments, must work collaboratively to gain a better understanding of the requirements of air transport in the future,” ATAG adds. Any delay could threaten the estimated 55 million tonnes reduction in CO2 emissions that SES promises.
SES is estimated to deliver a 10 to 15 per cent reduction in environmental impact alone thanks to savings of 300 to 500kg of fuel and 948 to 1,575kg of CO2 per flight, according to ATAG.
The US NextGen, meanwhile, is aiming for a cumulative reduction in carbon emissions of 14 million tonnes by 2020 as well as a 38 per cent reduction in delays by 2020; the installation of 700 automatic dependent surveillance-broadcast (ADS-B) stations across the US by early 2014; significant efficiency improvements in large metropolitan areas by 2014; and increased use of alternative fuels.
NextGen is based on the use of the latest ATM technology and procedures, including performance based navigation (PBN), RNAV/RNP based airport approaches, ADS-B, optimum descents and increased use of data link instead of voice communications.
Across the border in Canada, Nav Canada is aiming for a reduction in CO2 emissions of 21 million tonnes by 2020 – or $7 billion in fuel cost savings – through its collaborative initiatives for emissions reductions (CIFER).
While North America does not face the airspace fragmentation and multiple ANSP issues that Europe faces, NextGen still has its challenges, says ATAG, pointing to implementing the programme in a co-ordinated way, financial incentives for operators to adopt the new technology and obtaining user buy-in.
ATAG says policy makers in North America need to ensure the continued funding of NextGen initiatives that provide the earliest and greatest actual benefits in reducing fuel use and carbon emissions; increase the public-private partnership for NextGen equipage; ensure NextGen implementation is co-ordinated with aircraft manufacturers’ plans and operator upgrade plans; and accelerate the process for new procedures that take advantage of new technology.
The Asia-Pacific region is heading towards a Seamless Asian Sky. The Civil Air Navigation Services Organisation (CANSO) describes seamless airspace as “contiguous airspace that is technically and procedurally interoperable, universally safe and in which all categories of airspace users transition between flight information regions, or other vertical or horizontal boundaries, without requiring a considered action to facilitate that transition and without any noticeable change in type or quality of service received, air navigation and communications performance standards and standard practices to be followed.”
Rather than a single sky as in Europe, in Asia there would be a system of information exchange and co-ordination between ANSPs, resulting in far greater efficiency, says ATAG. “This is particularly critical in a rapidly growing market such as Asia, where a failure to stay in front of the capacity curve will directly impede growth and economic expansion,” it adds.
Asia-Pacific currently handles 26 per cent of the global passenger traffic and this is expected to rise to 30 per cent by 2015, with aircraft numbers to increase threefold over the next 20 years. The region will not be able to handle increases of this magnitude effectively and efficiently without significant enhancement of ATM processes, says the International Air Transport Association.
The region is aiming for Seamless Asian Sky by 2035. A report on the programme, including implementation timeframe and guidelines, is due to be presented at the next meeting of APANPIRG in June in Bangkok, Thailand.
The International Civil Aviation Organisation’s Block Upgrades (BU) programme, which was adopted by ICAO members in 2011, is designed to bring all of the initiatives together with the aim of achieving global interoperability by 2030. “The aviation industry agrees and is fully supportive of the block upgrades project which will bring much-needed efficiencies and even greater safety to our skies and our operations,” says Paul Steele, ATAG executive director.
The BU framework is based on specific performance capability modules which reflect the sector-wide consensus of the latest technologies and procedures entering service from existing ATM modernisation programmes, says ATAG. The BUs should be adopted on a global basis in order to deliver a seamless ATM system. The programme covers specific performance areas in four blocks of time. The first block upgrades are already widely available and include PBN and continuous climb and descent operations.
Projects and demonstrations involving new technology and processes included in ICAO’s BU plan conducted in recent years and ongoing have clearly demonstrated the possible capacity, efficiency, environmental and financial benefits.
Required navigation performance (RNP), which allows aircraft to fly precisely-defined paths without relying on ground-based radio navigation signals, offers huge potential, for example. Because of its precision, RNP allows aircraft to land in weather conditions that would otherwise have required a hold or diversion and shortens the distance an aircraft has to fly, reducing fuel burn, CO2 emissions and noise pollution.
The Brisbane Green Project in Australia in 2007, which involved Airservices Australia, Qantas, the Civil Aviation Safety Authority and GE Aviation, was the world’s first integration of RNP into a busy terminal environment.
In the first 18 months of the project, Qantas reported savings of 125,700 gallons of fuel, 1,100 tonnes of CO2, 17,800 track miles and 4,200 airborne minutes. RNP approaches were added to further airports in Australia, with airports seeing an average saving of 25 gallons of fuel and 250kg of CO2 per approach over conventional procedures. Qantas estimates that once the RNP system goes nationwide, it will save at least US$20 million a year in fuel and other costs.
Alaska Airlines’ Greener Skies project in 2009, involving the US Federal Aviation Administration, Boeing, Jeppesen and the Port of Seattle, saw the airline conducting RNP approaches to Seattle-Tacoma International Airport. The programme resulted in annual fuel savings of 6,500 tonnes and over 22,000 tonnes of CO2 emissions. As a result, Greener Skies became a national initiative in late 2011.
Flexible routing initiatives around the world, including IATA’s iFlex project, have also shown the possible fuel savings and reduction in emissions. ATAG says that although more than 90 per cent of aircraft today could fly a flexible route that takes advantage of the wind, fewer than 10 per cent actually do so. ATAG says based on a fuel price (as of end of 2011) of $979.90 per tonne, a Boeing 747 on a 12 hour flight with a 4.7 per cent weight penalty could save 156kg in fuel, 490kg of CO2 and $153 cost saving from a one minute saving on a direct route segment. At the end of the year, a single daily minute saved could result in a 88,950kg saving in jet fuel, 279,934kg of CO2 and $87.163.
IATA’s iFlex project is based on ultra-long-haul flights, using existing best practices, current technology and solutions that can be used across several FIRs. The first iFlex trial, operated by Delta Air Lines between Johannesburg and Atlanta, resulted in an average time saving per flight of eight minutes, equating to 900kg of fuel and 2.9 tonnes of CO2.
Efficient descents is recognised as one of the most significant changes that could save fuel and reduce emissions, with the US Three-Dimensional Paths in Arrival Management (3D PAM) and Initial Tailored Arrivals (ITA) projects, which are both part of NextGen, showing the benefits. Both projects involve flying aircraft on a fuel-efficient, conflict-free trajectory from cruise to the runway threshold with an optimised descent profile. 3D PAM involved the FAA, NASA, Boeing, United Airlines, Continental and American Airlines. Over 1,500 flight trials were conducted in 2010 and 2011 in Denver, Colorado, with a fuel-efficient, conflict-free trajectory used to meet the scheduled arrival time at a specific location. The project demonstrated schedule accuracy within 20 seconds and significant fuel-savings. 3D PAM will be implemented throughout the US between 2014 and 2018.
ITA involved the FAA, Boeing, NASA and airlines and used existing data link and ground system capabilities at US oceanic control centres to provide an electronic clearance for a fuel-efficient path to the runway. Flight trials between December 2007 and 2009 demonstrated savings of 225-1,270kg of fuel per descent. Airlines participating in the project at San Francisco saved over 1.5 million kg of fuel and reduced CO2 emissions by over 5.7 million kg. ITAs have since continued at San Francisco, Miami and Los Angeles and the FAA is looking to expand their operation at other airports.
Similar trials were conducted in the Netherlands at Schiphol Airport with KLM and by Airservices Australia at Melbourne Airport involving Qantas, Emirates and Singapore Airlines.
Collaborative flow management (CFM) is in operation by a number of ANSPs and proving its worth. Airways New Zealand, for example, has been using CFM to manage arrivals at its international airports. Ground delays are used to manage terminal area congestion at the destination airport. Aircraft do not leave the departure airport until they have been given an exact time of arrival at the destination airport, allowing flight at the optimum speed and no need to hold. Calculated arrival times are used throughout the flight.
Across the Tasman in Australia, Airservices Australia is using its Metron Harmony CFM tool to optimally align air traffic demand with available capacity. The collaborative decision making allows airlines to perform flight substitutions and other schedule changes to make the best use of their capacity.
The programme has resulted in reduced delays, fuel burn and emissions, says Airservices. Airborne holding into Sydney has been reduced by around a third and average flight times between Melbourne and Sydney have been cut by five minutes per flight, equating to more than 40,000 tonnes of CO2 a year.
A move from radar surveillance to satellite surveillance, such as automatic dependent surveillance-broadcast (ADS-B), is vital to improve the systems efficiency. ADS-B benefits are being demonstrated in Australia, the Gulf of Mexico, Canada and Indonesia. Nav Canada estimates its ADS-B deployment along the Hudson Bay, northeast coast and Greenland, could result in fuel cost savings through to 2020 of $379 million and a reduction in emissions of over a million tonnes.
An IATA cost-benefit analysis of implementing ADS-B in the South China Sea and involving Singapore, Indonesia and Vietnam, concluded there could be annual savings of around 1,300 tonnes of fuel and 4,500 tonnes of CO2 with an annual cost reduction of $4 million.
Collaborative programmes, like the Asia-Pacific and Indian Ocean initiatives to reduce emissions – ASPIRE and INSPIRE – brought together many of the ATM technologies and processes to demonstrate just what could be possible. The programmes made use of user preferred routes, dynamic airborne reroute procedures, reduced vertical separation minima, flexible tracks, continuous descent arrivals and tailored arrivals to deliver ATM best practice. The initial five ASPIRE demonstration flights alone achieved fuel savings of 32,386kg and a 101,986kg reduction in CO2 emissions. Procedures and services are now being implemented and used in every day operations.
Continued collaboration is key to improve ATM efficiency, says CANSO and Boeing in their Accelerating ATM Efficiency: A Call to Industry document released last year. “The opportunity and the needs are clear,” according to the partners. The challenge is great, but if industry implements seven steps, then change can be accelerated, they believe. The seven steps are to improve the collective understanding of the operational benefits of more efficient ATM operations; increase stakeholder collaboration; accelerate operational trials and procedures that take advantage of existing aircraft capabilities; accelerate “real time” collaborative decision making through enhanced information sharing; reduce airspace restrictions that lead to inefficient operations; accelerate the approval process for new procedures and operations; and promote best practices in ATM to ensure international harmonisation.
CANSO/Boeing say: “The aviation industry today has a unique opportunity to deliver immediate benefits in the form of increased capacity, reduced delays, increased efficiency and reduced noise, fuel burn and emissions.”