- author, Michael Dempsey
- Role, Technology Reporter
American startup Aerolane is looking to discover the secret to air surfing.
Geese actually know how to do this. When you see them flying in a V-formation, they are swimming on the air currents created by the formation members in front of and around them.
At one Texas airport, Todd Graetz hopes to use the concept to revolutionize the air cargo market.
Aerolane has managed to mimic the tricks used by migratory birds, with the help of modified aircraft that are towed into the air by another aircraft.
Smoke billowing from the lead plane allowed cameras mounted on the towed plane to capture vortices in the air that the glider could exploit to stay in the air.
Their latest test aircraft is known as the “flying piano” because of its poor gliding characteristics.
Its twin engines remain running for electrical power while the plane glides with the propellers spinning for purely aerodynamic purposes.
Further tests were performed to measure the tension in the diameter line.
They discovered when the line became slack, indicating that the glider was surfing the currents generated by the aircraft in front of it.
Aerolane’s plan is to feed all this data into software that will guide a cargo drone through waves and turbulence to exploit the potential of long-distance gliding without burning fuel.
One or more of these cargo planes can be towed by a jet, also carrying cargo, to its destination where it lands autonomously.
The only fuel costs will come from saving the engines of the tugboat.
In theory, this should work like a truck pulling a trailer, with the air currents doing most of the heavy lifting. It’s what Graetz calls “a combination of gliding and surfing.”
The same idea occurred to Airbus, which tested the technology in 2021 on two Airbus A350s flying 3 kilometers (1.9 miles) apart across the Atlantic Ocean.
Although the aircraft were not connected by a tow line, the trial saw one aircraft receive lift from the wake of the flagship A350 to reduce CO2 emissions and fuel burn.
Mr. Gratz, a pilot with 12 years of experience, founded Aerolane with Jor Kimchi, a veteran of Amazon’s drone delivery project, on the premise that “there has to be a better way to get more out of existing aircraft.”
The project has amazed experienced pilots. Flying large gliders in commercial airspace requires adherence to strict flight safety rules.
For example, the towing aircraft must be confident that it can release the towing line at any point during the flight, while ensuring that the autonomous glider can descend to the runway without falling on local residents.
Aeroline says a small electric motor that drives the propeller will act as a safety net on its cargo gliders, giving them enough power to spin again if a landing goes wrong or to divert to another location nearby.
Mr. Gratz responds that Aerolane employs active commercial pilots who are rational about the practical aspects of the project.
“We have appointed outside consultants to be devil’s advocates,” he added.
He says major shipping companies are interested in anything that allows them to lower the cost of delivery per shipment.
In addition to fuel costs, air cargo companies also have to consider jet engine emissions and a pilot shortage.
James Earle, a former RAF helicopter pilot and aviation consultant, believes Graetz may be onto something.
“It makes sense that we can make gains by combining efforts in the sky. Any innovation in shipping is a good thing.”
However, he cautions that the general acceptance of unpowered cargo flights over built-up areas is another matter entirely.
“It must have a good glide range to reach the landing point in the event of a major failure of the towing aircraft. However, whether that can be communicated effectively to the public is another matter.”
Mr. Graetz responds that his team has complied with every FAA request so far. “The FAA has always been very risk-averse. That’s their job!”
Fred Lopez spent 36 years in aviation operations at shipping giant UPS. As he says, he has spent his “entire adult life” finding the most cost-effective way to run an air freight business.
Mr Lopez admits he was deeply skeptical about cargo gliders when Aeroline first approached him. But the potential for significant fuel savings convinced him, and he now sits on its advisory board.
Reducing fuel costs is a major concern in civil aviation. When the inverted wingtips that we see from cockpit windows became a standard design feature, airlines managed to cut fuel costs by about 5%.
But gliders only use as much fuel as their towing aircraft needs. And if this is also a cargo plane, a pair of gliders towed by a single jet represents a significant reduction in fuel consumption on a large shipment.
The Aerolane’s initial design relies on an autopilot in addition to what Mr. Lopez calls a human “safety pilot.” That should make it easier to obtain FAA certification.
“Aerolane is not trying to change everything at once,” he says.
Their ultimate goal is autonomous operation using artificial intelligence, or as Mr. Lopez puts it, “pulling the pilot out of his seat.”
And if a flying piano can ride waves, who knows what might happen?