Due to pressure from pilots the U.S. Air Force accelerated the development of Auto-GCAS (Automatic Ground Collision Avoidance System) for the F-35 by about seven years. The initial tests of the F-35 version took place in November 2018. Pilots were already well aware of how many fatal (or nearly fatal) flight accidents have been avoided in jets using Auto-GCAS.
In 2014 the U.S. Air Force addressed the growing incidence of, frequently fatal, problems fighter pilots encountered in training or combat; disorientation and blackouts. High-speed maneuvers sometimes cause blackouts and loss of control of the aircraft. Disorientation is possible at any altitude but is most common when at low altitudes. Accidentally hitting the ground while flying low or in bad weather has long been a problem. The solution was new flight control software, much of it based on of decades work on similar software for commercial aircraft. By 2014 two new systems were in use for some jet fighters that had digital controls and space to add the computer hardware required. So far that means F-22s and 600 late model F-16s. In the four years since F-16s got Auto GCAS and PARS in 2014 at least seven pilots and their aircraft have been saved. That includes avoiding $350 million in losses. F-22s have this equipment as well and it is being implemented in late model Navy F-18s.
Auto GCAS will automatically take over the controls and return the aircraft to flying straight and level if it detects an imminent collision with the ground. Versions of his capability have been used in commercial aircraft for decades. Basic versions simply produced an audible “collision alert” so the pilots could take appropriate action. But there were cases where pilots, commercial or military, were distracted and ignored the alert until it was too late. Auto GCAS will automatically kick in if the pilot does not take action. For fighter pilots, especially those in single-seat aircraft, this has already proven to be a lifesaver in combat or training when the pilot passed out or became disoriented from high-gravity situations. In less than two years of operations, Auto GCAS has saved the lives of four fighter pilots, including at least one in a combat zone.
PARS (Pilot Activated Recovery System) is often referred to as a panic button for pilots who find themselves disoriented and possibly moving in a dangerous direction. This is a common problem in bad weather and at night. PARS will, one activated, operate in a similar fashion (and using some of the same hardware and software) as Auto GCAS to return the aircraft to flying straight and level. It’s difficult to say how many lives PARS has saved so far, but pilots flying in difficult conditions (as in the Middle East and Afghanistan) say it makes work a lot less stressful.
Before Auto GCAS fighter pilots, especially those in training, often died because high G-forces caused them to pass out unexpectedly. In training new pilots are taught how to handle these situations but while making a high-speed turn at high altitude a tiny miscalculation can cause an unexpected blackout. Fighter pilots are equipped and trained to deal with handling up to at least 9 Gs. But some of these methods require the pilot to contract abdominal muscles and take a deep breath to maintain consciousness. It is believed that many deaths were the result of the pilot forgetting to tighten up and take a deep breath, as he was concentrating on the complex, and high-G, a maneuver he was undertaking. The more recent fighter aircraft, especially those with digital controls, give pilots the option to get close to the high-G pass out threshold without passing out. In combat, this can be a lifesaver but learning how to do it can be dangerous, especially without GCAS.
G (gravity)-forces are not a problem for most other aircraft but are a critical shortcoming for modern fighters. Since the 1990s more powerful engines and computer-assisted flight controls have enabled fighters to not only execute increasingly violent maneuvers but to do it more quickly and in different directions. Because of this, medical doctors have gotten involved in the design of these aircraft, because the flight control systems have to be designed so that the aircraft cannot easily make a maneuver that the pilot cannot handle.
Since the 1960s a growing number of aircraft have been capable of executing maneuvers, usually sharp turns while moving at high speeds, that create a gravitational force (G-force) that causes the pilot to blackout. At first, it was believed special flight suits were the answer. These use small liquid or air-filled bladders to help prevent blood from rushing from the brain, and causing a blackout. But even with the G suit pilots found they still had to use their abdominal muscles and a deep breath to avoid blackout.
Since the 1980s computer-assisted flight controls have been developed that prevent the pilot from executing a maneuver that would exceed 9 Gs. But as aircraft become faster and more agile, there are more directions the aircraft can be going while pulling lots of Gs. Pilots now have to worry about neck injuries, if they execute certain maneuvers without positioning their head just so. Just another thing to keep in mind during a dogfight, in addition to the gut clench and deep breath. The basic design for a working GCAS system was available in the 1980s but the computer hardware needed to make it work was too bulky and difficult to maintain for fighter aircraft. In part, this was due to the lack of digital controls, which were slowly being introduced for commercial airliners.
It wasn’t until after 2000 that a lot of fighter aircraft were being equipped with digital controls. At the same time, computer hardware became smaller, more rugged and reliable and faster. By 2004 the air force saw that GCAS and PARS were now practical for high-end combat aircraft. Once it got installed in a lot of aircraft in 2014 and pilots could see how well it worked the entire combat pilot community became very aggressive in pushing the air force, navy and Congress to accelerate the installation of these new technologies in all modern fighters. Thus the F-35 got equipped much faster than planned.