- Author, Michael Dempsey
- Role, Technology reporter
American start-up Aerolane is looking for the secret of surfing in the air.
Geese already know how to do it. When you see them flying in a V-formation, they are surfing on the air currents created by the formation members in front of and around them.
At an airport in Texas, Todd Graetz hopes to use this concept to disrupt the air cargo market.
Aerolane imitates the tricks of migratory birds, using modified aircraft that are towed into the air by another aircraft.
The smoke from the lead plane allowed cameras in the towed plane to capture turbulence in the air. A glider can then use these turbulences to stay aloft.
Their latest test aircraft is known as the ‘flying piano’ because of its poor gliding properties.
The two engines idle for electric propulsion while the aircraft is in hover, while the propellers spin for purely aerodynamic purposes.
Other tests measured the tension in the towline.
They noticed the line going slack, indicating that the glider was moving with the current created by the aircraft in front of them.
Aerolane’s plan is to feed all this data into a program that can guide an unmanned cargo plane through wakes and turbulence, allowing it to take advantage of the potential to fly long distances without burning fuel.
One or more of such cargo planes could be towed to their destination by a jet aircraft also carrying cargo and land there autonomously.
The only fuel costs would come from the tow plane’s engines.
In theory, this should work like a truck pulling a trailer, with air currents doing the heavy lifting. This is what Mr. Graetz calls “a combination of gliding and surfing.”
Airbus also came up with the idea, testing the technology in 2021 with two A350 aircraft flying 3 km (1.9 miles) apart across the Atlantic Ocean.
Although the aircraft were not connected by a tow line, the experiment saw one aircraft lifted by the wake of the lead A350, reducing carbon emissions and fuel consumption.
Mr. Graetz, a pilot with 12 years of experience, founded Aerolane with Gur Kimchi, a veteran of Amazon’s drone delivery project, on the idea that “there has to be a better way to get more out of existing aircraft.”
The project has raised eyebrows among experienced pilots. Flying large gliders in commercial airspace means meeting strict flight safety regulations.
For example, the tow plane must be confident that it can release the tow line at any point in the flight, knowing that the glider on autopilot can reach the runway without crashing into the local population.
Aerolane says a small electric motor driving a propeller will act as a safety net for their cargo gliders, giving them enough power to re-land if a landing doesn’t seem to be going well, or to divert to another location nearby.
Mr Graetz counters that Aerolane employs active commercial pilots who are down-to-earth about the practical aspects of the project.
“We have hired outside consultants who act as devil’s advocates,” he adds.
He says major freight carriers are interested in anything that will help them reduce their cost per delivery.
In addition to fuel costs, air freight companies must also consider jet engine emissions and a shortage of pilots.
James Earl, a former RAF helicopter pilot and aviation consultant, thinks Mr Graetz may be right.
“It goes without saying that there are gains to be made by slipstreaming and combining efforts in the air. And any innovation in the cargo space is good.”
However, he warns that public acceptance of non-motorised cargo flights over built-up areas is a different story altogether.
“It needs to have a good glide range to reach a landing site in the event of a major failure of the tow plane. Whether that can be communicated effectively to the public is another matter.”
Mr. Graetz responds that his team has complied with every request from the FAA so far. “The FAA has always been super risk averse. That’s their business!”
Fred Lopez spent 36 years in the airline industry at freight giant UPS. As he puts it, he’s spent “my entire adult life” figuring out the most cost-effective way to run an air cargo business.
Mr. Lopez admits he was very skeptical about cargo gliders when Aerolane first approached him. But the prospect of serious fuel savings convinced him, and he now sits on their advisory board.
Cutting fuel costs is an obsession in civil aviation. When the upturned wingtips we see from a cabin window became a standard design feature, airlines cut fuel costs by about 5%.
But gliders only burn the fuel needed to tow their tow plane. If that is also a cargo plane, then a pair of gliders towed by a single jet plane represents a significant reduction in fuel consumption on a large shipment.
The original Aerolane design uses their autopilot plus what Mr. Lopez calls a human “safety pilot,” which should make FAA certification easier.
“Aerolane is not trying to change everything at once,” he says.
Their ultimate goal is autonomous operation using AI, or as Mr. Lopez puts it, “getting the pilot out of the seat.”
And if the flying piano can surf, who knows what else is possible?