Qantas’s big announcement earlier in May was that they would be starting 19-hour-plus ultra-long-haul flights direct from Sydney to London and New York by the year 2025.
The airline said the plan had been in the works for a number of years before COVID put it on ice temporarily.
In 2019 Qantas ran three trial flights to gather data for the Australian Civil Aviation Safety Authority about whether cabin crew, pilots and passengers can cope with that length of time in the air without a break.
During these test flights pilots wore brainwave monitors and were subjected to urine tests before and after the flight to track melatonin levels. Passengers in the cabin wore devices that allowed scientists to monitor and study their health and wellbeing and to assess how their body clocks were impacted throughout the flight.
The handful of journalists who joined the test flights say every aspect of the experience was meticulously planned to help reduce jet-lag from the 11-hour time zone leap. Measures included everything from instructions for an exercise regime down to the meal planning (for instance, chilli to boost metabolism).
Professor of sustainable tourism at Griffith University, Queensland, Susanne Becken, says despite the multiple airlines in the race to have the world’s so-called “longest flight”, the future of air travel would be much shorter, more sustainable flights.
The world’s longest flight currently is the 18 hour 40-minute haul from Singapore to New York City operated by Singapore Airlines. Other competitors include Cathay Pacific, which operates a roughly 17-hour Hong Kong to New York route.
“We know that more people are sustainability-minded and are considering their carbon emissions and other environmental factors when booking flights,” Becken told Cosmos Weekly.
“Long-haul flights are the most difficult to reduce the carbon of with new technologies. We have seen Qantas’s announcement and that in some ways is quite an unsustainable trend. But then there’s probably not really a trend in there.”
The maker of A350-1000, Airbus, is currently working on three concept aircraft with the aim of delivering the world’s first zero-emissions commercial flights by 2035. All three concepts in development are hybrid-hydrogen aircraft powered by hydrogen combustion; they use liquid hydrogen as fuel for combustion with oxygen in a modified gas turbine engine.
The plane maker says the hydrogen fuel cells will create electrical power that complements the gas turbine, resulting in a “highly efficient hybrid electric propulsion system”.
Airbus’s concept planes carry fewer passengers (between 100 and 200, depending on the aircraft) and have a much shorter flight distance (just over 3000 kilometres) than current commercial aircraft. But these designs and their capacity will increase over time as technology advances.
Becken says that along with Airbus’s investments there are many start-up projects looking at commercial electric aeroplanes, and that more efficient biofuels for shorter flights will greatly reduce emissions into the future.
Small electric aeroplanes have been rumoured to be just on the horizon for many years, with one Slovenian company already selling a fully electric small plane that has received airworthy certification. Its flight time is only 90 minutes maximum.
Ian O’Hara, deputy dean of the Faculty of Engineering at Queensland University of Technology, says despite aviation being one of the hardest industries to decarbonise, there is significant progress being made in the field of biofuels. He says these fuels are the future of commercial aviation.
“We have seven certified pathways for aviation biofuels to be blended which have been certified for commercial use and we are starting to get some significant global production,” O’Hara says.
He says many of these certified fuels are limited to 10% to 20% blends with traditional fuels, but that in some cases the biofuel can be up to 50% of the blend.
O’Hara says the pathway from which most of the world’s production of biofuels currently emanates is the hydroprocessed esters and fatty acids (HEFA). These are produced from used cooking oil, tallow and vegetable oils.
“However, production is starting to be developed focussed on the larger amounts of feedstocks available from surplus agricultural biomass, such as sugarcane bagasse, and also from the organic fractions of municipal solid wastes,” he says.
Sugarcane bagasse is a key ingredient in alcohol-to-jet synthetic paraffinic kerosene (ATJ-SPK). Fischer-Tropsch (FT) synthesis is a catalytic process applied to biomass waste to convert it to synthetic liquid fuels.
Another promising biofuel, according to O’Hara, is the High Hydrogen Content Synthetic Paraffinic Kerosene (HHC-SPK), which uses oils produced by algae. However, there’s limited production at the moment, and these fuels currently have low blend rates.
“Global aviation emissions will continue rising with travel numbers around the world, and for countries like Australia who are highly reliant on tourism and travel for that connectedness, it’s important that we dramatically invest in biofuels and sustainable options,” O’Hara says.
“We can reduce carbon emissions from flights by up to 80% compared to traditional fossil-based fuels [using these blended fuels],” he adds.
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O’Hara says that work on blended fuels is vital for the future of aviation. He says air travel customers were demanding more sustainable options for flying, and that without them people would turn away from the industry.
“Airlines are really driving this investment in research and development, but at the moment biofuels remain more expensive than fossil-based fuels, though that will change as more significant output of biofuels comes online,” he says.
O’Hara says that as well as industry, governments had a significant role to play in encouraging confidence and investment in the development of biofuels for the aviation sector. In the US, for example, the government had announced major signals to industry that biofuels had a huge role to play from 2030 and beyond.
“It’s all a matter of sending signals to industry, and for industry to bring more of that capacity online in a major way to drive down costs, because the technology is there,” he says.
Becken says that the broader future of air travel was hard to predict, especially as it was yet to be seen whether business travel would bounce back from the COVID pandemic, or whether the increased investment in remote working technologies would hamper business travel into the future.
“Airlines make more money off business travellers than tourists, so it’s hard to tell if this part of travel will be bounce back,” she says. “If it doesn’t, you could see a consolidation – less airlines around.”
“In five years from now, air travel will look largely the same as it does today, though in 10, 15 or 20 years, that’s when you will really start to see these investments in sustainability kick in,” she adds.
At the end of the day, science and the technological advancements in development will drive the future shape of air travel. Whether science can match the demands of increasingly environmentally conscientious travellers is yet to be seen.