Aircraft crossing the Atlantic can save between one and two per cent of the fuel costs per flight by varying their speeds and heights they fly, according to the latest results of a trial conducting by air navigation service providers in Canada and the UK and five partner airlines.

This translates to a reduction of 200 to 400 litres of fuel and 525 to 1,050 kilograms of GHG emissions. With close to 400,000 flights each year, the potential economic and environmental benefits are substantial.

As a flight transits the ocean, fuel is consumed and the weight of the aircraft decreases, resulting in the most efficient flight level becoming higher (assuming zero wind conditions). Therefore, an efficient flight profile may include a progressive or continuous altitude change and/or change in Mach (or speed), according to the trial’s organisers Nav Canada.

The project, titled ENGAGE II, was supported by The SESAR Joint Undertaking as part of its Atlantic Interoperability Initiative to Reduce Emissions (AIRE) programme.

The trials took place in airspace over the North Atlantic beyond the reach of Canadian or UK civil radar. The project was designed to promote the sustainable implementation and expand the scope of the concepts trialed during the first phase, completed in 2011. In addition to project partner Air France, four other international carriers – KLM, British Airways, United and Delta – participated in phase two.

ENGAGE II is paving the way for significant changes to operations in the North Atlantic At the June 2014 meeting in Paris of the North Atlantic Systems Planning Group – a body established by the International Civil Aviation Organization (ICAO) - the group endorsed a Proposal for Amendment to the North Atlantic Regional Supplementary Procedures that would allow some aircraft to fly at variable speeds.

The proposal to remove the requirement was made by Iceland, which provides air traffic services for a portion of the North Atlantic from Reykjavík. The proposed amendment will now proceed to ICAO for formal processing and documentation.