How Boeing converted F-16s into unmanned aerial targets
Boeing test pilot Jason Clements goes through final flight checks in the cockpit of an F-16. He makes sure all his switches are set, the throttle is free and clear, and the lights are on. Clements does a final radio check, and the jet is ready for takeoff. He then steps out of the cockpit and closes the canopy via remote switch. The F-16 takes off with no human occupant. What in the world just happened?
Clements is part of a joint Boeing/Air Force project to convert retired F-16s into unmanned systems; these aerial drones will present a unique challenge for pilot trainees — the most realistic, 4th-generation targets short of a full-scale engagement. Cadets will fire real weapons systems at these “QF-16s”, and while the drones won’t shoot back, they’ll present a modern, highly maneuverable, and difficult to visually acquire target. And when the QF-16s crash, it will cause zero casualties. Welcome to the Air Force of the future (or, at the very least, the most realistic training simulation on Earth).
“Training realism” is the main goal of the program, noted former Air Force Major General Steve Sargeant, now the CEO of Marvin Test Solution, a T&M company that services legacy fighters, among other projects.
Over the course of a long, distinguished career in the United States Air Force that spanned more than three decades, Steve flew a number of aerial systems, including the F-16 Falcon, which he described as a “very capable multirole fighter.”
This is key, because prior to the QF-16, the military relied on a modified version of the F-4 Phantom, a legacy aircraft (3rd-generation) in use since the Vietnam War. The QF-16 provides trainees with a highly-realistic 4th-generation aerial target.
“It’s a replication of current, real-world situations and aircraft platforms they can shoot as a target. Now we have a 9G capable, highly sustainable aerial target,” said U.S. Air Force Lt. Col. Ryan Inman, Commander, 82nd Aerial Targets Squadron.
Under the QF-16 Air Superiority Target (AST) Program, the USAF plans to convert up to 126 retired F-16s into remote-controlled aerial systems that, according to Boeing, can be tracked and targeted—and ultimately shot down—by warfighters as part of their training in weapons and tactics. The F-35 Joint Strike Fighter — the “backbone of America’s tactical aviation fleet for decades to come” — will replace the F-16 (among other jets) in the near future, so this recycling program, as it were, is a great way to mitigate spiraling defense costs.
Boeing accomplished this conversion process — a true technical marvel — by applying reverse engineering practices and performing rapid prototyping as part of their risk reduction plan. The company utilized a technology called the “X-ray Backscatter Non Line of Sight Reverse Engineering System,” and according to Boeing, the QF-16 program applied reverse engineering practices to accurately design the modifications required for conversion of the aerial targets.
“Prior to contract award, we used the X-ray scanning and laser scan data to develop 3-D models of the design,” said Bob Insinna, QF-16 program manager. “We reduced program risk by performing rapid prototyping of the flight termination system and a smoke generation system.”
Indeed, creating viable F-16 drones was no easy task. I spoke with Paul Cejas, Chief Engineer of the QF-16 program, and he noted that while the actual conversion process was straightforward, the challenge was “finding sufficient space in a jet with existing systems to add over 3000 wires and several new systems. That required us to remove some hardware that was not essential to our mission, and create new installations in the same footprint.”
“The other biggest challenge was understanding the electrical systems and displays of the F-16 and tapping into them without affecting performance,” he said. “This allowed us to send aircraft on-board information to the ground station so that it could be flown safely. The most difficult part, however, was the flight software, especially to land the aircraft safely.”
The first retired F-16 arrived at Boeing's Cecil Field facility in Jacksonville on April 22, and the aerospace giant has already converted six jets into QF-16 aerial drones. The QF-16 flew its maiden voyage on September 19, 2013, performing a series of simulated maneuvers, reaching supersonic speeds, returning to base, and landing. Two pilots controlled the modified F-16 from the ground, and the first unmanned QF-16 Full Scale Aerial Target flight was a smashing success. Lt. Col. Inman called it “a great flight all the way around.”
So we know that the QR-16 will be an invaluable training aid, replacing a particularly obsolete aircraft. But could it be more than that? After all, unmanned systems intrinsically allow for increased pilot safety. One could argue that safety is a UAV’s chief advantage over the manned variety. “The unmanned vehicle is another tool to help accomplish those missions safely,” noted Paul Cejas.
In her blog post, “Will the QF-16 be the next step in drone warfare?”, my colleague, Kasey Panetta suggested that the QR-16 could represent the natural evolution in aerial warfare. Kasey ponders “Why risk a pilot’s life when the planes can be controlled from the ground?” And the F-16 sports aerial capabilities that dwarf our current arsenal of Predators, Reapers, and other UAVs.
But for now, at least, the QR-16 will remain a training tool. Until we create a truly autonomous aerial platform that doesn’t require human input, unmanned vehicles will be at the mercy of its human (ground-based) pilot.
The QF-16’s performance capabilities are also subject to the whim of its design. While an unmanned system that isn’t saddled by the biological limitations of human could theoretically outperform manned fighters, we’re not there yet.
“In this application,” notes Cejas, “unmanned does not allow us to increase G-forces because the airframe is still limited.”
“A new unmanned airplane could potentially provide higher G-forces, but that would provide benefit in only limited circumstances,” he said.
We’d also need to prevent adversaries from hacking the data link and capturing an advanced 4th-generation drone. Iran’s recovery of a U.S. RQ-170 was a prescient reminder that cyber warfare is very real (and costly).
And from my conversations with Paul Cejas and Steve Sargeant, I got the impression that a human pilot (in the cockpit) would still outperform a remotely-piloted vehicle. “The fighter pilot, unlike the UAS platforms, has to be responsive to a very dynamic and complex environment,” claimed Sargeant.
Only an autonomous aircraft — with an airframe that can accommodate higher g-forces — could truly outperform manned aircraft (remotely piloted or not). For now, the Air Force will have to “settle” for a highly-capable, 4th-generation aerial target.