Could drones supplant MacDill's aerial tankers?
As local politicians and business leaders jockey to bring as many as 36 of the next generation of aerial refueling tankers to MacDill Air Force Base — providing a big boost for the local economy — consider this:
In a report about unmanned aviation systems published in January by the Congressional Research Service, Jeremiah Gertler broaches the idea that the KC-135 Stratotankers — and by extension the next-generation KC-46As — could someday be replaced by drones.
"Tanker flight profiles are relatively benign compared to many others, and they tend to operate far from enemy air defenses," wrote Gertler in the report, titled "U.S. Unmanned Aerial Systems."
"Except for operating the refueling boom (to refuel Air Force aircraft), the refueling crew's primary job is to keep the aircraft flying straight, level, and at a steady speed."
Gertler describes himself as a "specialist in military aviation."
I'm no specialist, but having watched a KC-135 crew out of MacDill refuel a B-52 several miles in the air, straight, level and steady, it is no easy feat.
That said, Gertler wrote his report because unmanned aerial systems "comprise a rapidly growing portion of the military budget, and have been a long-term interest of Congress. At times, Congress has encouraged the development of such systems; in other instances, it has attempted to rein in or better organize the Department of Defense's efforts."
I came across the report last week while researching the maritime version of the Predator, called Guardian.
Gertler only devotes a few paragraphs of his 55-page report to unmanned refueling systems, but with manned tankers playing a key role in the local economy, it's worth listening to what Gertler has to say.
He cites two unmanned aerial vehicles as potential replacements for planes like the KC-10 and the KC-135, 16 of which are based at MacDill.
The first is a proven unmanned vehicle, the Global Hawk, a jet-powered drone. The second is the experimental X47-B, a "tailless, strike fighter-sized unmanned aircraft currently under development by Northrop Grumman as part of the U.S. Navy's Unmanned Combat Air System Carrier Demonstration Program," according to the company's Web site (Northrop Grumman also makes the Global Hawk).
"In July 2010, the Defense Advanced Research Projects Agency awarded a contract to demonstrate refueling by Global Hawk UAVs, and a March, 2011 test demonstrated the Global Hawk's ability to receive refueling autonomously," Gertler wrote. "The Global Hawk's 2001 transoceanic flights (from the United States to Australia and from the United States to Portugal) demonstrate the ability of current UAVs to fly missions analogous to aerial refueling missions."
This same technology, he wrote, could allow drones to refuel manned aircraft. Northrup Grumman hopes to demonstrate "autonomous aerial refueling by the X-47B aircraft" in 2014.
That's all well and good, but Gertler doesn't factor in payload.
The Global Hawks can carry a payload of about a ton and a half, according to Northrop Grumman. While the company doesn't specify the payload of its experimental X-47-B, no fighter-sized aircraft could compete with what are essentially flying gas stations.
With a payload capacity of 200,000 pounds, the KC-135 can carry about 70 times as much fuel as the Global Hawk. And the KC-46A can carry even more fuel — 207,000 pounds, according to the Air Force.
On top of that, U.S. Reps. Kathy Castor and C.W. Bill Young insist that the new tankers remain a priority for the Air Force.
So while drones may have value as eyes in the sky, replacing the Stratotanker or its replacement may be pie in the sky.