Environmentally friendly air traffic management demonstration flights sound good in theory, but they need to be more than attempts to gain positive publicity. The Asia and Pacific Initiative to Reduce Emissions (Aspire) is one green ATM programme that appears to walk the walk as well as talk the talk. Processes and technology highlighted in Aspire demonstration flights are increasingly being put into daily operation, and partners are striving to make every flight perfect in terms of reduced fuel use and emissions.
Airservices Australia, Airways New Zealand and the US Federal Aviation Administration established the partnership in February 2008 to accelerate development and implementation of operational procedures to reduce aviation's environmental footprint for all phases of flight.
The civil aviation authorities of Japan and Singapore have since joined, while Aerothai was in June endorsed as the next member.
© Airways New Zealand
ANSPs must prove they can meet Aspire goals by teaming up with a local airline to carry out green demonstration flights
To join, air navigation service providers (ANSP) must show they can become regional leaders in emissions reductions. They must prove their service provision is in line with Aspire goals by demonstrating their commitment and ability to create performance metrics, implement Aspire best practices, procedures and services and participate in and support Aspire work programmes.
After joining, an ANSP is required to partner a local airline in a demonstration flight using "green" ATM procedures and technologies. Five gate-to-gate demonstration flights have been conducted across the Pacific by airline partners Air New Zealand, Japan Airlines, Qantas, Singapore Airlines and United Airlines. All used procedures including no- delay taxiing, unimpeded climb-out on departure, user preferred routes (UPR), dynamic airborne reroute procedures (DARP), performance-based navigation (PBN), reduced vertical separation minima (RVSM), optimised profile descents and tailored arrivals.
The flights saved 32,390kg (71,400lb) of fuel and cut carbon dioxide emissions by 101,990kg, Maria DiPasquantonio of the FAA's air traffic international office told the recent International Civil Aviation Organisation Colloquium on Aviation and Climate Change.
Lessons learned are being fed back into day-to-day operations. For example, changes were identified for DARP after the Qantas Airbus A380 Aspire flight between Melbourne and Los Angeles in November 2008. Airservices Australia says as a result of that flight, significant changes to automated controller-pilot datalink communications message processing within Airservices' Australian Advanced Air Traffic System were identified, designed and are in the process of being implemented.
The Aspire partners have identified 10 procedures and services that have a proven effect in cutting fuel and emissions in each phase of flight - UPR, DARP, oceanic separation reductions, RVSM, flexible track systems, surface movement and runway monitoring, departure management, arrivals management, continuous descent approaches and PBN. Aspire partners are working to implement the procedures on a daily basis throughout the region and are progressing in many areas, the partners say.
The first of nine implementation initiatives is DARP Enhancements, which is aimed at identifying and removing institutional, procedural and technological barriers to the implementation and adoption of DARP in the region. Although DARP was demonstrated in 1999, by 2008 it was used on only 5% of flights between North America and Australasia, with airlines citing an increase in dispatcher workload as one reason for not taking it up.
Aspire is promoting DARP as a standard service as it saves a considerable amount of fuel. Air New Zealand, for example, estimates it could use less fuel on 58% of its flights from Auckland to North America using DARP, with an average saving of 453kg of fuel per flight. DARP is available in all FAA South Pacific airspace for FANS-equipped aircraft and in the Auckland flight information region. Airservices Australia is automating DARP processing.
The Aspire partners are also working to remove constraints to the expansion of UPRs. UPRs are available in the oceanic portions of flights between North America and Australasia for FANS-equipped aircraft. Aircraft without FANS can request a UPR for select city pairs. The Aspire partners are examining how UPRs can be made available for flights between Japan and Singapore, while Airservices is expanding UPR availability and plans to make it available throughout the Australian FIR by mid-2011.
Oceanic and remote in-trail procedures (ITP) are also a focus, with the partners keen to foster the deployment of automatic dependent surveillance - broadcast ITP, initially in the South Pacific. Business and safety cases have been produced and operational trials are being planned, headed by the FAA. They are set to start at the end of this year, says Greg Houghton, senior adviser ATM planning at Airservices Australia.
Business and safety cases have also been completed for oceanic automatic dependent surveillance-contract (ADS-C) climb-descent procedures with a view to launching operational trials in the South Pacific in November, adds Houghton.
The Aspire partners are also evaluating a further reduction of oceanic separation standards. The FAA is conducting a feasibility study, looking in particular at whether the benefits of having additional capacity on optimal routes will exceed the costs of providing further reduced separation standards.
Arrivals and departures optimisation are key aspects of Aspire's work. Major airports in the region, including Osaka's Kansai, Melbourne's Tullamarine and San Francisco International, already support optimised profile descents on a trial basis with approved airline partners.
Optimised arrivals offer clear environmental benefits, with an estimated 617kg of fuel saved per flight using a tailored arrival into San Francisco, for example. The Aspire partners say they are creating mechanisms to expand arrivals optimisation to additional airports.
Auckland airport allows optimised arrivals on an ad hoc basis, with procedures and technology to be in place next year to standardise optimised profile descents. In addition, the Singapore civil aviation authority has completed its second optimised profile descent operational trial in conjunction with Singapore Airlines at Changi airport and is looking to expand the programme with other carriers. In Australia, Airservices is rolling out required navigation performance (RNP)-based arrivals optimisation at airports throughout the country.
© Airservices Australia
Aspire partners have identified 10 procedures that save fuel and cut emissions
The partners have also put in place initiatives to optimise departures through minimising ground delays and optimising the climb to cruise level. In Australia, for example, Brisbane, Melbourne and Sydney airports are using an auto-release procedure whereby tower controllers can clear aircraft for take-off without having to rely on time-consuming voice communications with the terminal area controllers. In New Zealand, trajectories are optimised for individual flights, allowing for uninterrupted climb where possible. The FAA is developing a tool to improve the efficiency of the climb, while Japan's civil aviation bureau is developing a departure optimisation programme.
The Aspire partners aim to encourage emissions reductions at the same time as allowing for continued traffic growth in the region through reduced horizontal separation through the use of RNP10 and RNP4 performance-based separation standards in the South China Sea and the Bay of Bengal. The Singapore authority has been leading efforts in this programme, implementing 50nm (93km) longitudinal separation in the South China Sea in 2008, with plans to implement 30nm longitudinal-30nm lateral separation next year.
Aspire partners are also working to implement ADS-B in the region, with ADS-B supporting emissions reduction through more efficient routeing as well as increasing safety. Aspire is working with Vietnam and Indonesia to implement ADS-B in the South China Sea. Australia, meanwhile, completed the implementation of ADS-B in its upper airspace at the end of last year. In Australia, the implementation of ADS-B has allowed separation standards to be reduced from 30nm to 5nm at and above flight level 290, resulting in improved flow management, less restrictive weather diversions, quicker access to preferred routes, less position reporting, a reduced cockpit workload and improved situational awareness, according to Airservices.
To assess the success of its initiatives, the Aspire partners have undertaken several performance measurement tests. These include the development of a model showing efficiency gains in the South Pacific over the past decade to highlight how much individual procedural changes have contributed to emissions reductions. Between Australasia and the US West Coast, for example, initiatives such as RVSM and UPR have resulted in average fuel savings of 2.6% in oceanic en route airspace over the decade, according to the partners.
The group is also developing an "ideal flight" benchmark metric to show the greatest emissions cuts possible using the current fleet and using all available fuel-saving procedures and services. The metric will be used to develop emission-reduction targets for each phase of flight. A baseline flight metric is also being developed to determine average emissions for Australasia-North America as now flown to act as a baseline to measure the effects of future implementations.
The Aspire partners realise that to achieve maximum emissions reductions, best practices need to be used every day. To encourage airlines and ANSPs, Aspire is developing a concept for green Aspire star-rated city-pair designations, whereby higher star ratings will be given to those city pairs that have more best-practice procedures and services available.
For example, a route with RVSM and 30nm/30nm separation would have two stars, while one with RVSM, 30nm/30nm separation, DARP and UPR would be an Aspire four-star route. The partners say airlines will be encouraged to document and publicise their use of Aspire star routes, motivating ANSPs to implement best-practice procedures and services and resulting in a network of green routes throughout the Asia-Pacific region.
Meanwhile, Airservices is to expand the activities pioneered by Aspire across the Indian Ocean under a new initiative - the Indian Ocean Strategic Partnership to Reduce Emissions (Inspire). While Aspire is focused on the South Pacific, North Pacific and South-East Asia, Inspire will aim for environmental benefits in the Arabian Gulf-Australia, southern Africa-Australia/South-East Asia, and south-west Indian Ocean-Arabian Gulf regions.
Initial partners Airports Authority of India, South Africa's Air Traffic and Navigation Services, the United Arab Emirates General Civil Aviation Authority and Oman's Directorate General of Meteorology and Air Navigation are on board, says Airservices Australia, which aimed to have an Inspire "informal commitment signed off"by the end of July, leading to a formal signing and finalisation of the group's strategy and work priority, says Houghton.
Inspire will include demonstration flights, similar to those operated under Aspire, with the possibility of simultaneous flights. Emirates and Etihad Airways are "very enthusiastic" about being involved, says Houghton.