What happened
On the evening of October 9, 2024, during twilight hours, two private aircraft experienced a loss of separation while approaching runway 07 at Carrasco International Airport (SUMU) in Uruguay. The first aircraft, a Beechcraft V35B (registration CX-MCB), was arriving from a flight in the Salto Department. The second aircraft, an AgustaWestland A139 (registration LV-KJB), was conducting a passenger transfer flight from Buenos Aires (SABE).
During the final approach, air traffic control assigned the Beechcraft V35B priority as number one in the sequence. The helicopter was instructed to follow as number two, maintaining distance from the preceding aircraft. While the helicopter was crossing the runway perpendicular to the approach path, the two aircraft reached a minimum separation of only 0.2 nautical miles (approximately 37 of 370 meters) at the same altitude. To prevent a mid-air collision, the pilot of the Beechcraft V35B was forced to execute an evasive maneuver. Both aircraft subsequently landed without damage, and all occupants were uninjured.
The investigation
The CIAIA investigation examined the communications between the pilots and the air traffic control tower, as well as the operational procedures during a shift changeover. The investigation established that the air traffic controllers were in the process of a shift handover when the incident occurred. The investigators also reviewed the flight documentation and the pilots' experience levels, noting that the helicopter pilot was not familiar with the destination aerodrome.
Findings
- Inaccurate pilot report: The pilot of the LV-KJB helicopter provided incorrect information to air traffic control by stating he had the preceding aircraft in sight when he actually did not.
- Operational error: The helicopter pilot continued on a trajectory that led to a crossing of paths with the lead aircraft at the same altitude.
- Reporting failures: There was a significant lack of immediate reporting; the helicopter pilot and air traffic control personnel did not report the incident, and the pilot of the CX-MCB did not notify authorities until 24 hours later.
- Safety culture concerns: The investigation noted that the pilot of the CX-MCB initially expressed an intention to withdraw the report to avoid the investigation process.