In the years ahead, the technology will be installed in the fifth-generation, “fly-by-wire” F-35 Lighting II jets, said Amy C. Burns, the Air Force Research Laboratory program manager of the automatic collision avoidance technology initiative.
“It comes on at the very last second, it quickly recovers the jet and (then) gives control back to the pilot,” she said.
Seventy-five percent of F-16 crashes involve the single-engine fighter jet flying into terrain, a pilot experiencing spatial disorientation or G-induced loss of consciousness, according to Air Force statistics. The new technology could prevent crashes in all of those instances, AFRL says.
‘A good safety net’
For 40 years, pilots found manual warning systems a nuisance in F-16s, and the older systems did not improve the rate of accidents per flight hour, AFRL researchers reported.
The Ohio Air National Guard’s 180th Fighter Wing was one of the first to install the Auto Ground Collision Avoidance System in the Toledo-based unit’s F-16s. The fighter pilots, who stand watch on a continuous homeland defense mission, gave feedback to AFRL researchers about the new technology, said 1st Lt. Justin Guinther, a F-16 pilot.
“I wouldn’t say we fly any differently having the Auto GCAS there, but it’s definitely a good safety net,” Guinther said. “We like the fact that it’s always running in the background and it can save us from our mistakes.”
Pilots can turn the system off for low-level bombing strikes, an Air Force spokesman said.
Another 24 percent of F-16 losses are attributed to mid-air collisions. AFRL is at work on an aerial collision avoidance system and has flight tests on an integrated system with both technologies set through 2017.
The Air Force has no plans to install the technology on F-15 Eagle or A-10 Thunderbolt II jets because they are controlled by hydraulic cable flight controls, unlike later “fly-by-wire” combat aircraft controlled through electrical signals, said Wright-Patterson spokesman Daryl Mayer.
The Air Force counts more than 1,000 F-16s in its fleet. The oldest models — some 400 in all — carry analog flight control computers that aren’t compatible with Auto GCAS.
AFRL researchers are working on a fix to install the technology in the future, Mayer said.
Saving lives
In the past year, AFRL credited GCAS with saving the lives of two pilots, one on a strafing mission at an undisclosed location and a second pilot in a training dogfight over the Mediterranean Sea, said Burns, the AFRL program manager.
In November 2014, a pilot on the strafing mission made “multiple passes” with frequent radio communications chatter, Burns said. “The pilot was very fixated on this target,” she said.
The F-16 was in a dive at about 575 miles per hour with the right wing down. A manual warning system began chiming “altitude, altitude, altitude” about 2,000 feet above the ground, Burns said.
GCAS kicked in less than four seconds before impact, the researcher said. Typically, the system rolls the wings level in a 5G recovery, but the pilot aided in pulling the Fighting Falcon jet out of its dive and sustained nearly 8Gs a little more than 500 feet above the ground.
“If the pilot would not have pulled the extra Gs, it would have actually pulled him out about 300 feet above the ground,” she said. “So it’s very last second.”
In January, GCAS was credited with saving the life of an F-16 pilot in a dogfight over the Mediterranean Sea, Burns said, who added the aviator thanked researchers for saving his life and the aircraft.
Richard Aboulafia, a long-time aviation analyst with Virginia-based Teal Group, said some pilots accustomed to being in command in the cockpit may be resistant to giving up control.
“There is some institutional resistance from the pilot community, but on balance it seems like something that will be accepted more and more as they refine the technology,” Aboulafia said. “It has been proven to save lives.”
Aboulafia added the Air Force has relied more and more on high-altitude precision bombing and less on lower altitude strikes where the technology works.
How it works
Engineers program digital maps of the terrain the jet flies over with the aid of Global Positioning System satellites and Inertial Navigation System technology to avoid obstacles and steer clear of the ground, Burns said.
NASA flew more than 100 flights testing the technology at Edwards Air Force Base in the California desert before the Air Force installed it in F-16s last year.
“During this flight test, we proved this system was not only nuisance free, but also could have protected against almost all past, historical mishaps that we’ve lost due to controlled flight into terrain,” Burns said.
Along with real world flights, AFRL researchers tested the software in high-tech flight simulators at Wright-Patterson that mimic flying low to the ground in an F-16 cockpit.
The accuracy of the digital maps is critical to the performance of the system.
Burns said the crash avoidance system might not have worked in two prior mishaps. In one, an F-16 crashed into a ground tower, and in the other, electrical wires had a role in the crash.
Both obstacles were not in the digital terrain database, Burns said.
“The system is only as good as the digital map that you load on board the aircraft,” she said.
About the Author