Point of Recovery: Ground Collision Avoidance System saving pilots lives

  • Published
  • By Tech. Sgt. Brandon Shapiro
  • Airman Magazine

Frantic calls of “Two recover, Two recover, Two recover,” echoed across the airwaves.

Maj. Luke O’Sullivan, F-16 Fighting Falcon instructor pilot, watched helplessly from his cockpit as his student’s jet descended from an altitude of over 3 miles to under 4,400 feet in a matter of seconds.

While executing a more than 8-G turn, the over 1,000 pounds of pressure had drained the blood from the student’s brain, causing tunnel vision and impairing his ability to rationalize.

Within seconds, he was a victim of gravity-induced loss of consciousness.

Given the rapid rate of descent, O’Sullivan knew there was no way the pilot could regain consciousness in time to pull out of the free fall.

In less than four seconds, his student would be dead — except, he didn’t die. Instead, the essentially pilotless F-16 rolled upright, pulled a 5-G climb and then leveled off.

The pilot’s savior: a technology developed in the 1980s known as the Automatic Ground Collision Avoidance System.

“When I saw the aircraft pull out of the rapid descent, all I felt was relief; I was very, very thankful that the jet had recovered,” O’Sullivan said. “At first, I had no way of knowing if it was Auto GCAS that righted the aircraft or if it was the student who had regained consciousness in time to execute the recovery. It wasn’t until after the mission and when we watched the HUD (head-up display) tape, we could piece together he had lost consciousness and the system engaged – ultimately helping to save the student’s life and the aircraft.”

Auto GCAS was initially masterminded by five computer scientists, who were also aerodynamicists, at the Air Force Research Laboratory (AFRL) at Wright Patterson Air Force Base, Ohio. The system was designed to automatically fly an airplane away from an impending ground collision, preventing the loss of the pilot and aircraft.

After years of testing and improvements in digital mapping, the system became fully functional in the early 1990s; however, the program was halted based on data referencing spatial disorientation flight into terrain.

In 2003, Col. Pete Mapes, a pilot physician, was asked to go to AFRL and conduct an extensive review of the program. There he found inconsistencies with the reported data, specifically on Auto GCAS. After the colonel cross-referenced the previous data and conducted his own research, he realized the initial analysis of the program was missing a crucial component.

“The study I received did not have denominators and was not usable, so I set about verifying all of the mishap report data and getting denominators from (the Air Force Operations Training Division) in the form of flying hours,” Mapes explained. “Once that data was collected, the pattern became extraordinarily clear. The majority of deaths in fighter/attack aircraft were not due to combat, and it wasn’t due to mechanical causes; the deaths were occurring either because the reaction timing of the human beings in the cockpits sometimes fell below the reaction timing required to avoid collision with the ground or because the human was incapacitated.”

Mapes had found the answer. He now had the concrete evidence needed to lobby the for the program’s integration.

“Imagine that,” Mapes exclaimed. “A single technology addresses more than three quarters of the deaths in fighter aircraft and preserves the combat capability as well.”

Less than a year later, Mapes presented his findings to the Joint Safety Summit in Destin, Florida. There he unveiled a case for the system that allowed for its implementation.

He concluded that for every dollar spent on Auto GCAS, the Air Force would preserve $65 in airframe acquisition, in addition to the ultimate benefit of returning pilots back safely to their loved ones.

Mapes’ extensive research led the Air Force to give approval for the software’s integration on select F-15 Eagles and F-16s that contained digital computers compatible with the Auto GCAS software.

The AFRL’s development and testing, which evaluated 103 flights and recorded 1670 automatic fly-ups without a single failure, was concluded in the fall of 2010.

By 2016, the anti-collision software was installed on more than 600 F-16 aircraft, resulting in three confirmed reports that Auto GCAS saved both the pilot and aircraft. In May, the system reported its fourth.

“The value of the four lives saved so far is incalculable, the combat capability preserved is precious to this country, and the public affairs worth of preventing our enemies from claiming a ‘kill’ is immense,” Mapes said.

According to predictions based on historical accident rates, the Air Force expects that Auto GCAS will save 10 lives, upward of 14 aircraft, and more than $530 million over the projected remaining service life of the F-16 inventory alone. Add in the fact that the software is scheduled to be installed on both the F-22 Raptor and the F-35 Lightning II and the figure may exceed $18 billion.

In layman’s terms, Auto GCAS is a system that takes control of the aircraft when there is an impending certainty of a ground collision. It accomplishes this feat through a predicted trajectory, based on GPS positioning and system altitude, which is compared with an on-board Digital Terrain Database.

Once the program recognizes the aircraft is likely to crash, it prompts the pilot to evade either a ground crash or a controlled flight into terrain situation. If no action is taken, Auto GCAS assumes temporary control, engaging an autopilot maneuver to roll the aircraft upright and initiate a 5-G climb, diverting the plane and pilot out of harm’s way.

After putting the aircraft on a safe trajectory, the system then returns aircraft control to the pilot.

According to Amy Burns, a program manager with AFRL, it takes a very specific set of circumstances for the system to engage. The system must also satisfy three requirements in order of priority before initiating: do no harm, do not interfere, and prevent collisions.

Do no harm: The system shall not cause the aircraft to depart controlled flight, automatically maneuver outside aircraft or pilot limits, or put the aircraft or pilot in a dangerous situation.

Do not interfere: The system shall operate in the background, allowing the pilot to fly low-level missions, employ air-ground weapons, perform air combat maneuvers, and fly in close formation. It should only activate when required to prevent ground collisions.

Prevent collisions: The system shall automatically maneuver the aircraft to prevent ground collisions.

Auto GCAS system has been both revolutionary and lifesaving, but continued research has yielded an additional upgrade to the program: the Automatic Air Collision Avoidance System.

Auto ACAS, like its big brother, automatically prevents crashes; however, in this case, it prevents air collisions.

From Auto GCAS to Auto ACAS to the effort to combine both into an even newer Auto ICAS (Automatic Integrated Collision Avoidance System), the Air Force continues to ensure that the safety of the pilot and the integrity of the aircraft remain paramount. Over the next five years, modifications will be made to the fighter fleet, ensuring that the mission prevails and pilots return safely to their families.