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The US Air Force is implementing automatic ground collision avoidance system (auto-GCAS) technology on much of its fighter fleet nearly 30 years after the technology was developed. Auto-GCAS has the potential not only to save lives, but also save money by reducing accidents, which is ultimately what convinced the Pentagon to adopt the technology. Auto-GCAS dates from the mid-1980s when the USAF was working on the Advanced Fighter Technology Integration F-16 prototype. But while the system worked, data storage was not sufficiently developed for auto-GCAS to be implemented on operational aircraft. Nonetheless, the experience provided valuable data. The current USAF effort has its origins in the Automatic Collision Avoidance Technology/Fighter Risk Reduction Project that began in 2004. An Auto-GCAS could significantly reduce critical fighter-aircraft mishaps resulting from pilot spatial disorientation, loss of situational awareness, G-induced loss of consciousness (G-LOC) and gear-up landings. While cost savings are what ultimately sold auto-GCAS technology, its most important benefit is that it can save lives. Indeed, engineers see no reason similar technology could not be installed in civilian airliners. Given the potential to enhance safety, serious consideration needs to be given to adopt auto-GCAS for wider applications.

Potential hazard

  1. Identify any areas where an Auto-GCAS might impede a pilot’s performance of standard commercial aviation operations.
  2. Because pilots are adamant about having final authority over their aircraft, the AFTI test team initially gave the pilot an ability to always override the Auto-GCAS. Extensive testing, plus discussions with F-22 test pilots, changed that attitude.
  3. “During all-terrain testing, we found that even the slightest override of the GCAS autopilot in the wrong direction would blast you through the [MDA] floor,” Mark Skoog said. “Trying to do elevated-g fly-ups, we saw hundreds of feet of additional altitude loss due to a 0.3-sec. override. We came out of the program knowing that we’d have less protection by giving the pilot total autopilot override [authority]. So, we lock-out the pilot in roll and yaw. He can add pitch up to the angle-of-attack limits,” and can always deactivate the Auto-GCAS by hitting a “paddle” switch at the base of the control stick, or pushing with 19 lb. of force.

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