Air Traffic Incident Involving TAP Air Portugal and OMNI Aircraft Near Lajes (CS-TEH)

Incident Overview and Aircraft Details On August 20, 2004, a TAP Air Portugal Airbus A310-300, registration CS-TEH, departed Lisbon Airport for a scheduled passenger flight to Lajes Airport. The aircraft carried 135 passengers and 9 crew members. Separately, an OMNI Beechcraft B200, registration CS-DDU, departed Lajes Airport for a positioning flight to Cascais Aerodrome with 2 crew members on board. ## Sequence of Events The TAP aircraft was descending toward Lajes when it received traffic information regarding the OMNI aircraft, which was climbing. At approximately 09:18 UTC, the OMNI aircraft was cleared to climb to flight level 160. As the two aircraft approached each other, air traffic control issued instructions for both to turn right. The TAP aircraft's Traffic Collision Avoidance System (TCAS) subsequently issued a resolution advisory for an immediate descent. ## Consequences and Injuries The TCAS-mandated descent caused the TAP aircraft to experience negative G-forces, resulting in a 600-foot altitude change. Passengers and cabin crew who were not wearing seat belts were thrown against the cabin ceiling and seats. This resulted in minor injuries to 36 passengers and 2 crew members. No fatalities or serious injuries were reported. The aircraft landed safely at Lajes Airport, and the injured were transported to a hospital in Angra do Heroísmo. ## Investigation Findings The investigation determined that the incident was caused by a loss of minimum separation between the two aircraft. The TAP aircraft was equipped with TCAS, while the OMNI aircraft was not. The analysis of flight data and TCAS performance did not lead to significant changes from the preliminary report's conclusions.