Automatic Ground Collision Avoidance System design, integration, & flight test

• Published in: IEEE aerospace and electronic systems magazine Vol. 26; no. 5; pp. 4 - 11
• Main Authors: Swihart, D E, Barfield, A F, Griffin, E M, Lehmann, R C, Whitcomb, S C, Flynn, B, Skoog, M A, Processor, K E
• Format: Magazine Article
• Language: English
• Published: New York IEEE 01-05-2011; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aerosapce control; Aerospace safety; Aerospace testing; Aircraft; Automotive engineering; Collision avoidance; Control systems; Fighter aircraft; Grounds; Level measurement; Navigation; Pilots; Reduction; Terrain mapping
• ISSN: 0885-8985; 1557-959X
• DOI: 10.1109/MAES.2011.5871385

Currently, the majority of collision avoidance systems on fighter aircraft depend on the pilot taking action whenever a warning is issued by the manual system. Any future substantial reductions in mishap rates will require extending the collision avoidance technology to systems that not only warn the pilot but also take control and fly the aircraft out of danger before returning control to the pilot. An Automatic Ground Collision Avoidance System (Auto GCAS) will provide this extension of collision avoidance technology. Much work has been accomplished over the past 20 years in the developing and testing of an Auto GCAS. In the past three years, a Fighter Risk Reduction Program (FRRP) has been undertaken by the Air Force Research Laboratory (AFRL) at Wright Patterson Air Froce Base. This program is a joint effort between AFRL, NASA Dryden, Lockheed Martin Aeronautics, and the Air Force Flight Test Center. The FRRP has advanced Auto GCAS technology to a level now capable of production transition. Results of this effort will be discussed herein. The F-16 test aircraft is shown in Figure 1. Controlled Flight Into Terrain (CFIT) is defined as collision with terrain, water, trees, or a man-made obstacle during flight prior to planned touchdown. CFIT includes mishaps where the aircraft is controllable and the pilot is actively controlling the aircraft or the pilot's ability to control the aircraft is reduced due to spatial disorientation. CFIT also includes mishaps where the aircraft is flown in controlled flight to a point where it is no longer possible to avoid unintended ground impact (attempted maneuver with insufficient altitude or airspeed, low altitude over bank, or flight into a box canyon), regardless of subsequent pilot reaction (add power, maneuver to avoid terrain, etc.). Prevention of CFIT mishaps utilizing Auto GCAS will be presented. The requirements for Auto GCAS and the order of importance of those requirements are discussed herein. This will show why prevention of a nuisance warning has a higher priority than the aircraft recovery and how an automatic system can be designed to basically eliminate nuisances. Discussions will include techniques to develop nuisance criteria by utilizing a Pilot Activated Recovery System (PARS). Discussions will include how the PARS are used to improve flight safety. In 2005, a goal of reducing CFIT mishaps by 75% was established. To accomplish this goal, the Undersecretary of Defense for Personnel and Readiness established a Defense Safety Oversight Council (DSOC). The DSOC further chartered nine Task Force teams targeting multiple areas where mishap reduction could occur. One task force, the Aviation Safety Improvement Task Force (ASITF) was chartered with reducing aviation mishaps. The ASI TF formed integrated product teams and working groups to assess aviation mishaps and recommend feasible and effective mitigation strategies. The Safety Technology Working Group (STWG) was the ASI TF working group charged with identifying technological mitigation strategies for aviation mishap reduction. The STWG recommended Auto GCAS as the means to achieve the goal of reducing CFIT mishaps.