What happened
On July 11, 2015, a Boeing 787-800 was performing a final approach to runway 10C at Chicago O’Hare International Airport. During the approach, the aircraft's Traffic Collision Avoidance System (TCAS) issued a Resolution Advisory (RA) to the crew, indicating a need to perform a maneuver to maintain separation from other traffic.
In response to the alert, the crew disconnected the autopilot and executed the maneuver as directed by the TCAS system. Following the completion of the RA maneuver, the crew continued the approach and landed the aircraft safely.
The investigation
The investigation, conducted by the operator, established that the TCAS alert was triggered by another aircraft that was simultaneously conducting an approach to a parallel runway. The crew reported the incident to air traffic control services following the event.
Findings
- The primary cause for the TCAS Resolution Advisory was the presence of another aircraft on an approach to a parallel runway.
- The crew followed standard procedures by executing the TCAS-mandated maneuver and subsequently notifying air traffic control.