In nailing down his first patent, Air Force Lt. Grant Schlichting embraced an old technology, made some tweaks and potentially developed an innovative approach to aerial towing.
“Aerial Tow Re-hookup is essentially trying to extend the range of an aircraft,” Lt. Schlichting said. “It’s similar to aerial refueling, but instead of transferring fuel, we treat powered aircraft like gliders mid-air.
“An airplane would take off on its own, then shut down an engine. It would then be towed to its area of operation and relaunched, performing an air start with the windmilling turbine. This is useful for various applications, including electric air vehicles, which can recharge during the towing sequence.”
With fuel savings and extended aircraft range, the concept has several other potential benefits, especially in the context of future warfare.
“There are 'loyal wingmen' — unmanned fighter drones that will fly alongside our fighter pilots,” said Lt. Schlichting, who found the inspiration for his idea through the United States’ use of Gliders in World War II and the Air Force Academy’s glider program. “These drones will require a lot of fuel, and we may not have enough refueling capabilities to support a significant increase in the number of drones in the sky."
Aerial towing offers a solution by allowing manned aircraft to transport multiple drones to the battle, reducing the need for individual refueling.
“You could have a four-ship of aircraft flying with their loyal wingmen, bringing them to the fight," said Lt. Schlichting, a graduate of the Air Force Academy with a master’s degree in aerospace engineering from Georgia Tech. "Instead of using drop tanks like on previous airplanes, you'd simply drop the tow rope."
Drop tanks are used on fighter aircraft to carry extra fuel. Once they reach a battle zone, they need to be combat ready. They have limitations, so they’re sometimes dropped.
This approach not only extends the range of unmanned aircraft but also addresses the challenge of anti-access aerial denial, which makes it harder to launch from a runway within a certain radius. Towing offers a way to deploy aircraft from safer distances.
And there are hypersonic considerations in the technology, as well.
“One of the limiting factors for space tests, hypersonic vehicles and weapons employment in general is safe separation and storage space,” Lt. Schlichting said. “These factors are fixed, but with a glider vehicle, you can tow a package of any size and launch or recover it with a different system.”
Lt. Schlichting also sees this technology as an asset for companies like Amazon or FedEx.
“Instead of taking a giant load to one city and dispersing it from there, one plane could tow multiple gliders, launch them and deliver to smaller locations,” he said. “This would cut delivery times and reduce the time spent on the road.
“Imagine an aircraft towing multiple packages, bringing them up to 30,000 feet, and then releasing them for delivery, or having them take off on their own. I envision that in the future.”
When it came down to locking up the patent, Lt. Schlichting did find some difficulty in establishing his aerial vehicle towing system as truly unique.
“Every time I researched the patent lineage, something would come up that could potentially mitigate my patent, so I'd have to rework it, rephrase it and really try to find the uniqueness,” he said. “Ultimately, the unique aspect was the ability to reconnect mid-flight.
“Another challenge was self-doubt. You want to make sure you're creating something worthwhile and not just something that's already been devised and wasting people's time.”
As for the future of this technology, Lt. Schlichting has some thoughts about what’s next.
“The next step would be to conduct flight testing with an actual system, such as drones, and prove that you can have a tow platform, a ‘mothership,’ with three drones connecting mid-flight,” Lt. Schlichting said. “By demonstrating and quantifying the increased combat capability or fuel savings, we could then make a case for this technology to receive a grant or other funding to further develop it.”
Currently, Lt. Schlichting is in the Euro-NATO Joint Jet Pilot Training Program at Sheppard Air Force Base in Texas.
United States Patent Office Patent: #12, 134, 482
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