More flights, fewer emissions and quicker passenger journey times – this is the future of air travel.
By 2050, every flight in the world could be on average 13 minutes shorter and save approximately nine million tonnes of excess fuel annually.
This equates to over 28 million tonnes of avoidable CO2 emissions and passenger savings of over 500 million hours of excess flight time on board an aircraft.
According to leading aircraft manufacturer Airbus, the future of aviation depends on sustainability.
The comany’s ‘Smarter Skies’ vision suggests five ways to optimise aircraft operation, both on the ground and in the air, by 2050.
1. Eco Climb:
As space becomes a premium and mega-cities a reality, this approach also could minimise land use, as shorter runways could be utilised.
The power needed to take off is determined based on runway length, wind speed, temperature, and the weight of the aircraft.
An assisted takeoff – using some form of propelled acceleration – would allow planes to be lighter, with smaller engines consuming less fuel and climbing to its most efficient cruising altitude more quickly.
With less time and distance required for takeoff, runways could be shortened by up to a third, minimising land use and enabling airport capacity to increase or new micro-airports to emerge.
A continuous “eco-climb” would further cut noise and CO2 emissions, particularly if renewable fuels were used.
2. Express Skyways:
While borders have fallen at ground level, the same can’t be said for the skies above. As flights transit a patchwork quilt of international airspace they are passed between disparate air navigation service providers and diverted into sets of air corridors.
The result is circuitous, zig-zag flight patterns. But what if the skies were stitched into one seamless blanket?
Aircraft could navigate more directly and thus more quickly, efficiently and safely through optimal gate-to-gate flight paths or express flyways. On an Airbus test flight from Brussels to Stockholm, a 20 minute gain meant fuel savings of 725kg, in turn reducing CO2 emissions by 2,283kg.
A generation of intelligent aircraft could also utilise 4D navigation to self-select the most efficient route, making optimum use of prevailing weather and atmospheric conditions.
Just as birds heading south for the winter save energy by flocking together, formation flight can also boost the efficiency of commercial aircraft.
Trailing planes can effectively “surf” on the energy coming from the wing tip vortices of the preceding aircraft. This reduces drag, which increases fuel efficiency and minimises engine emissions.
A safe flight separation of apporximately 20 wingspans – far less than the four nautical miles that separate civil aircraft today – is sufficient to reap the benefits.
3. Free-glide approaches to landing:
Allowing aircraft to take free glide approaches into airports would lower emissions during the overall decent and reduce noise during the steeper approach as there is no need for engine thrust or air breaking.
These approaches also would reduce the landing speed earlier, making shorter landing distances achievable with less runway needed.
Today aircraft descend in stages and often are forced to wait in the air, circling in holding patterns to avoid congested airspace or while awaiting a landing slot. However, levelling off during descent requires an increase in thrust. That means extra fuel burn and emissions – as well as unnecessary delays for passengers.
With better air traffic management, aircraft could enter a fuel-efficient descent based on when best to leave cruise level – with no risk of getting stuck in traffic.
Aircraft featuring technology to optimise landing positions with pinpoint accuracy could glide smoothly into airports with their engines running in idle, for significantly reduced fuel burn, emissions and noise.
4. Ground operations:
On landing, aircraft engines could be switched off sooner, runways cleared faster and ground handling emissions could be cut.
Technology could optimise an aircraft’s landing position with enough accuracy for an autonomous renewably-powered taxiing carriage to be ready, so aircraft could be transported away from runways quicker, optimising terminal space, and removing runway and gate limitations.
Simply switching engines off sooner on the ground would make a big difference. According to the International Air Transport Association, up to six million tonnes of CO2 could be saved each year by reduced engine taxiing.
The use of sustainable biofuels and other potential alternative energy sources will be necessary to secure supply and further reduce the environmental footprint of air travel for the long term.
This will allow the extensive introduction of regionally-sourced renewable energy close to airports, feeding both aircraft and infrastructure requirements sustainably.
The potential benefits of this solution to the long-term availability and affordability of fuel means it is fast becoming a very real and viable option with 50/50 blend biofuels already certified for commercial flights.
While it is not foreseeable that fuel cells would be used for commercial aircraft propulsion, they are one of the most promising ‘step change’ technologies to power cabin operations.
Over 1,500 commercial flights worldwide have been flown on biofuels to date. So the burning question is, when will sustainable biofuels become the industry standard?