Incident
While cruising at Flight Level 350 over the Gulf of Mexico, the flight crew received a climb resolution advisory from the Traffic Alert and Collision Avoidance System (TCAS). The crew initiated a climb at 1,500 feet per minute, subsequently increasing the climb rate to 2,500 feet per minute. During this maneuver, a passenger standing near the aft galley sustained serious injuries.
Conflicting Traffic
The traffic that prompted the TCAS advisory was a NASA T-38A aircraft conducting a functional check flight. During a stall series, the T-38A had descended through Flight Level 350. The pilot of the T-38A then initiated a climb back to above Flight Level 350. The T-38A was operating under Visual Flight Rules (VFR) based on a letter of agreement, and its pilot had been advised by air traffic control not to descend below Flight Level 350 due to numerous traffic in the area.
Regulatory Context
The letter of agreement between Houston Air Route Traffic Control Center (ARTCC), NASA, Houston Intercontinental Tower, and the 147th Fighter Interceptor Group at Ellington Field, Texas, was found to be in violation of existing International Civil Aviation Organization (ICAO) agreements. The letter was rescinded on March 10, 1993, the day following the accident.