What happened
On October 26, 2022, at approximately 12:20 UTC, a serious incident involving two helicopters occurred near the LONES waypoint, vertical to the São José dos Campos (SBSJ) aerodrome. The first aircraft, a BK117 D-3 registered PS-HAI, was conducting an IFR training flight from São Paulo. The second aircraft, an A1/A109E registered PT-SVB, was performing an IFR proficiency check ride for the renewal of its crew's instrument ratings.
During IFR procedures, the two aircraft experienced a loss of separation, reaching a minimum longitudinal distance of 0.2 NM and a vertical separation of only 100 ft. The crew of PT-SVB reported receiving a Traffic Collision Avoidance System (TCAS) Resolution Advisory (RA), which prompted an abrupt evasive maneuver. Neither aircraft sustained damage, and there were no injuries to the four crew members or one passenger involved.
The investigation
CENIPA's investigation focused on the air traffic control (ATC) environment and the flight profiles of both aircraft. Investigators found that the aircraft PT-SVB climbed to 7,000 ft, exceeding its authorized altitude of 6,000 ft. The investigation also noted that the radar track for PT-SVB had become uncorrelated in the controller's system, making it difficult to monitor.
At the time of the incident, the air traffic controllers were managing a combined sector (T-12 and T-14) that contained eight aircraft, exceeding the maximum allowable limit of six. The investigation established that the process of decombining these sectors was delayed, and the handover of traffic information was occurring simultaneously with the occurrence, which hindered effective monitoring.
Findings
- High Controller Workload: The delay in decombining sectors T-12 and T-14, combined with the number of aircraft exceeding the operational limit, compromised the air traffic controller's ability to identify conflicting flight paths.
- Loss of Situational Awareness: The decorrelation of the PT-SVB radar track and the high workload led to a degradation in the controller's ability to perceive and project the future status of the aircraft.
- Unauthorized Altitude Change: The crew of PT-SVB climbed above the authorized altitude, contributing to the breach of minimum separation standards.
- Communication and Coordination Failures: Inadequate interaction among the ATC team and a lack of timely communication regarding sector decombination contributed to the escalation of workload.
- System Inadequacy: The failure of the SAGITARIO system to maintain a correlated track for PT-SVB reduced the controller's attention toward that specific aircraft.