Secretary of Transportation’s Award Goes to Kathryn Ciaramella

The DOT Secretary’s Award has been presented to Tech Center mathematician Kathryn M. Ciaramella for improving the safety of the NAS through stress analysis that confirmed the need for, and specifying the limitations of, a proposed change to the Traffic Alert and Collision Avoidance System algorithm.

On July 1, 2002, a mid-air collision between a Boeing B757-200 and Tupolev TU154M occurred near Ueberlingen (Lake Constance), Germany. Kathryn Ciaramella performed an analysis of the incident using different versions of the Traffic Alert and Collision Avoidance Systems (TCAS) logic for the National Traffic Safety Board. Since that time, a number of near mid-air collision incidents, similar in geometry, have occurred and were documented both within the U.S. and Europe.

As part of its investigation into these incidents, Eurocontrol researchers identified a section of the TCAS algorithm which it believed could be modified to allow an escape maneuver reversal by an aircraft when its TCAS recognized that the other aircraft was behaving contrary to the resolution advisories issued by its TCAS. Eurocontrol presented its logic change proposal (CP112-E) to the FAA and RTCA for evaluation and adoption. If adopted, then a change to the minimum operational performance standards would follow.

Ms. Ciaramella was charged with stress testing the Version 7 TCAS logic with CP112-E to verify that it would perform as expected as compared to the baseline version. She conducted this simulation with intruder aircraft equipped with the current operational logic versions, i.e. Versions 6.04A and 7, at varying altitudes, pilot response models, and geometries. Out of the 10.5 million simulated encounters run, not only was she able to isolate 450 cases where the change did not perform as well as desired, but identified the altitude region where CP112-E benefits could be realized.

She presented her work at the RTCA Special Committee 147 Requirements Working Group (RWG) meeting in June 2005 where it was examined and accepted “as-is” and unanimously by the TCAS experts from the FAA, Eurocontrol and MIT Lincoln Laboratory with the avionics manufacturers in attendance.