Rannoch Corporation has completed initial testing of an alerting system that provides runway incursion alerts directly to pilots of GA (general aviation) aircraft.

Rannoch's  PathProx system uses ADS-B (automatic dependent surveillance-broadcast) and/or TIS (traffic information system) uses data from other aircraft and ground vehicles, within a defined proximity of the user's aircraft, to track their movement.  When prescribed decision rules are met, the system alerts the pilot, with annunciations analogous to those of TCAS (traffic alert and collision avoidance system), based on the traffic's location and movement.

The system can be used in a standalone mode where it receives information from other aircraft and vehicles, or it can use of any other ground-based airport surveillance information that may be available, Rannoch says.

In the user's aircraft, a PathProx displays a moving map of the airport, and the runway in use, along with traffic information including its identification, distance and time to potential incursion, if applicable.

Like TCAS, the system has two levels of warning implying two levels of severity, but unlike TCAS, it doesn’t provide advisories or guidance. (The feasibility of avoidance guidance is being studied, however.) The first level, a "runway traffic alert," indicates the potential for a runway incursion, while the second "runway conflict alert," indicates a runway incursion that has potential for collision, and appropriate action should be taken.

The GA testing consisted of both flight and simulator tests conducted at Ohio University's Snyder Field in Athens, Ohio, and at NASA's research center in Langley, Virginia.  An Ohio University King Air C90 and a Rannoch test vehicle were each equipped with PathProx, a prototype EFB (electronic flight bag) and an airport surface moving map display, provided by Strategic Aeronautics Corporation.  The EFB was used to display traffic information and to annunciate the incursion alerts.  Sixteen pilots flew a variety of runway incursion scenarios in the simulator at NASA Langley, using different GA cockpit displays.

Rick Cassell, Rannoch's director of safety systems, said the system's advantages include situational awareness, self-separation, and conflict detection and alerting without reliance on ground infrastructure and air traffic control.

PathProx was originally developed for commercial operators, but over the last two years, under contract to NASA, Rannoch adapted it to GA operations.  10-21-2005.

SAFETY BENEFITS OF PATHPROX
This paper analyzes the safety benefits of the implementation of PathProx, a runway incursion alerting system. Airport surface incursions have been identified by the National Transportation Safety Board (NTSB) as one of the most significant safety hazards in civil aviation. PathProx is a system developed by Rannoch Corporation to help address this problem. It is an aircraft-based runway incursion alerting system, providing runway incursion alerts directly to the pilot(s) in the cockpit.

INITIAL TEST RESULTS OF PATHPROX
This paper describes the initial test results of PathProx - a runway incursion alerting system, intended to help minimize the number of runway incursions and provide conflict alerts for all aircraft and vehicles on the airport surface. Rannoch Corporation is the developer of PathProx, an avionics system designed to provide timely alerts directly to the pilot. The test results presented in this paper are primarily based on testing accomplished at Dallas - Fort Worth International Airport October 2000m as part of NASA Runway Incursion Prevention System (RIPS) tests.