The U.S. Air Force is more than midway through the first phase of flight tests of the Automatic Integrated Collision Avoidance System (Auto ICAS), thought to be the world’s first fully automatic integrated combat flight safety system designed to prevent both air-to-air and air-to-ground collisions.
Auto ICAS builds principally on the Automatic Ground Collision Avoidance System (Auto GCAS), which has been officially credited with saving at least three F-16s and their pilots since entering service with the Air Force in late 2014. The system, which was developed by Lockheed Martin, the Air Force Research Laboratory and NASA, was integrated into the Air Force’s F-16 Block 40/50 fleet as part of the M6.2+ operational flight program (OFP) software update. Auto GCAS protects pilots by taking temporary command of the aircraft and executing an automatic recovery maneuver when it detects an imminent impact with terrain.
Auto GCAS continually compares the trajectory of the F-16 with a terrain profile generated from an onboard digital terrain database. When the system detects a threat, an evasion command is issued; if no action is immediately taken by the pilot, the system automatically assumes control. The Auto ICAS will extend this protective envelope by integrating the ground-collision-avoidance function with the recently developed Automatic Air Collision Avoidance System (Auto ACAS) that completed its initial flight testing in 2014.

Following evaluation of both Auto AGAS and Auto ACAS, F-16s of the Air Force’s 416th Flight Test Sqdn. are now testing the combined Auto-ICAS safety system. Credit: U.S. Air Force


Auto ACAS, which is hosted on a modified ASQ-T50(V)1 P5 wingtip-mounted air combat maneuvering instrumentation (ACMI) training pod, is fail-safe. It will not activate with bad data or failures that prevent safe operation, and it is designed not to interfere with normal operations or impede mission performance during combat training. The system works cooperatively, sharing position data with other pod-equipped aircraft in its area. The Auto ACAS algorithm works by continually building trajectories that look 4.5 sec. into the future. The trajectories change as the systems on each aircraft cooperatively negotiate and evaluate automatic avoidance maneuvers.
“The design premise of Auto ICAS is to prioritize Auto GCAS functions while making the Auto ACAS function 'terrain aware' to ensure that Auto ACAS never commands an avoidance maneuver that would require a corresponding Auto GCAS maneuver,” says Ed Griffin, Lockheed Martin program manager of the Automatic Collision Avoidance Technology Fighter Risk-Reduction Program.
Testing of the initial Auto ICAS by the Edwards AFB, California-based 416th Flight Test Sqdn. began in May, and by early August, 17 flights had been completed for a total of 33.5 hr. The flights build on an initial evaluation conducted in September 2015 under a small, student-led test management project (TMP) at the U.S. Air Force Test Pilot School. The TMP, which was similar to those conducted for the early phases of Auto GCAS and Auto ACAS, proved the basic concept by flying the school’s NF-16D Vista (Variable Stability In-Flight Simulator Test Aircraft) in maneuvers against virtual targets and another F-16.
“Completed testing includes regression of F-16 systems, multiple collision avoidances with a virtual aircraft, target aircraft equipped with a legacy ACMI pod and a dissimilar fighter aircraft using the F-16 radar,” says Griffin. The initial dissimilar flight test was flown in July against a NASA F-15. Two- and three-ship collision avoidance and nuisance potential testing is planned later in Phase 1, which is scheduled to conclude this September. 
Because Auto ACAS processing is contained primarily in the ACMI pod and Auto GCAS is hosted internally on the advanced data transfer equipment, the two systems in Auto ICAS are designed to communicate across the standard F-16 1553 data bus. A planned upgrade to the ACMI pod, which would have provided additional processing power as well as RF bandwidth, encryption and compatibility with the F-35, has been delayed, however. 
Lockheed says the second phase of flight tests is expected to start in February 2017 after the implementation of system software improvements. Phase 2 is expected to conclude in the summer of 2017 after the combined completion (including Phase 1) of around 110 flights.
Meanwhile, new details of the latest acknowledged “save” of an F-16 and its pilot have emerged; the incident occurred during basic fighter maneuvering training. During the maneuvering, a student pilot in a single-seat aircraft blacked out and, despite repeated calls from the instructor flying close by, was descending rapidly toward terrain when the system recovered the aircraft. The student regained consciousness and landed safely. A fourth suspected save—involving a near collision with terrain during low-level training—is also being investigated.