Etihad Airways, the national carrier of the United Arab Emirates, has successfully performed the world’s most intensive sustainable flight testing program, operating 42 flights over five days to test operational efficiencies, technology, and procedures that will reduce carbon emissions.
The program, coinciding with Earth Day 2022, included 22 contrail prevention flights over three days.
Tony Douglas, Group Chief Executive Officer, Etihad Aviation Group, said: “We believe this is the most intensive sustainability flight testing program ever conducted, the results of which will contribute to reducing aviation’s carbon emissions and environmental impact as the learnings are implemented into standard airline operations across the industry.
“Some of the technologies and operational efficiencies we have tested can be implemented today and we’re well in the process of putting these innovations into standard operational procedures, which we hope to see replicated across the industry, while some technologies are still in their infancy and we’ll continue to work with our partners to test and develop these for future use. However, there are several impactful solutions which are ready to go, but require industry and regulatory response to become practical, that the industry needs to raise to the challenge for.”
Etihad points to Sustainable Aviation Fuels (SAF), which are more than six times more expensive than conventional aviation fuels at the moment and incredibly difficult to the point of impractical to procure, acknowledging that both SAF and Lower Carbon Aviation Fuel (LCAF) are needed for aviation’s energy transition.
“This challenge needs policy changes from Governments, continued R&D, supply chain enhancements, and refining improvements,” said Douglas.
“The other big area, which has a simple solution but requires fundamental restructuring to the way things currently work, is for the industry, traffic controllers, and regulators to modernize flight paths for controlled climbs and continuous descent. In our demonstration EcoFlights, we’ve been able to take at least 40 minutes out of flight times and reduce the CO2 content by around six tonnes, which is incredible.”
Etihad’s newest aircraft and sustainability beacon alongside its established Greenline program, the Sustainable50 A350-1000, officially became the first A350 to operate as an EcoFlight.
“Operating EcoFlights on the A350-1000 is a big step forward as an example of the world’s two largest aircraft manufactures working in tandem for the mutual objective of aviation decarbonization through Etihad’s comprehensive Sustainable50 and Greenline sustainability program.”
Technology and processes tested included:
Optimized Flight Paths: Coordinated with ANSPs to optimize flight paths, direct routing, and optimized descent.
Contrails Prevention: When water vapor is ejected from the engine exhaust into the sufficiently cold air, it condenses, creating tiny ice crystals. In certain atmospheric conditions, these ice crystals create layers of cirrus clouds, causing a ‘blanket’ effect that keeps warmer air trapped in the lower atmosphere. Working with UK-based SATAVIA, Etihad avoids flying into these areas, reducing non-CO2 emissions.
Variable speed during the cruise: Pilots use specific software that suggests an optimal cruise speed based on actual atmospheric conditions and the weight of the aircraft. Etihad is one of the few airlines that partner with Boeing for the development of this software. The fuel savings are about 1.5% for each flight.
Reduced Flaps for Landing: when landing on sufficiently long runways, using reduced flaps reduces the drag and requires less thrust and less fuel consumption during the approach phase. It reduces the noise disturbance near airports as well. This results in approximately 30kgs of fuel-saving for each approach.
Reduced engine taxi: most of the ground movements are conducted utilizing only the power of one engine. By shutting down a single-engine aircraft when it lands, Etihad reduced carbon emissions produced by 20 to 40%.
Cabin lights off for one minute during flight: a symbolic act for Earth Day happening across the world from 8:30 pm to 9:30 pm, Etihad’s EcoFlight was a first for the industry.
The Greenline and Sustainable50 programs in partnership with Boeing, Airbus, GE, and Rolls Royce is Etihad’s platform to foster industry collaboration and tackle the biggest challenges the industry faces for decarbonization, operating as a testing platform as well as call to industry, governments, and regulators for solutions-driven collaboration.
Through these programs, and Etihad’s ongoing research and testing initiatives such as EcoFlights, Etihad encourages and invites partners from across the aviation sector to join and test sustainability initiatives on scheduled 787 and A350 operations. The results are then processed and validated, with the most sustainable initiatives used as a base for improving the performance of the global airline community.
The results and data from Etihad’s Earth Day EcoFlight and Contrail flight testing program will be formulated and analyzed over the coming weeks, to be added to the knowledge base it has built to support the aviation industry on its journey to decarbonization.