Wrong flight number, 2 planes violated safety separation

On June 21, speaking with Tuoi Tre Online , Director of the Civil Aviation Authority of Vietnam Dinh Viet Thang said he had received information about two flights violating horizontal separation due to air traffic control's mistaken flight number.

The incident occurred in the airspace controlled by the Ho Chi Minh Area Control Center (ACC Ho Chi Minh) on the morning of June 19.

According to Mr. Thang, during the flight, the air traffic controller mistakenly ordered an aircraft to adjust altitude to avoid another aircraft. In fact, that flight was not adjusting altitude but was instead approaching another aircraft.

The reason for the confusion was that at that time air traffic control was operating many flights, including two flights with flight numbers HVN 1575 and HVN 1557 that could easily cause confusion.

"The incident caused two planes, flight numbers HVN 1575 and VJC 244, to fly in opposite directions at the same altitude but 8 nautical miles (NM) apart, equivalent to about 15 km. Meanwhile, the horizontal separation on the same plane is at least 10 nautical miles, about 18.5 km," said Mr. Thang.

According to Mr. Thang, the two planes were traveling in opposite directions, violating the horizontal separation of about 3 km, but both the ground system and the aircraft's collision warning system warned of a conflict, so the pilots and air traffic controllers were able to handle it.

The Civil Aviation Authority preliminarily determined that this was a level D incident (an incident that posed a safety threat), but the incident was under control as the pilot and air traffic controllers both knew about it and needed to make adjustments, so the Authority assigned the Vietnam Air Traffic Management Corporation to verify and report to the Authority.

According to information from the Vietnam Air Traffic Management Corporation, on the afternoon of June 19, this enterprise received a preliminary report from the Southern Air Traffic Management Company on the incident related to the conflict warning involving flights HVN 1575, HVN 1557 and VJC 244 at division 1 (Ho Chi Minh City Long-distance Control Center).

The incident occurred at around 6:30 a.m. on June 19 when air traffic controllers gave instructions to flight HVN 1557 from Hanoi to Da Lat to adjust flight level.

Meanwhile, flight VJC 244 from Ho Chi Minh City to Thanh Hoa is maintaining a flight level close to flight HVN 1557. At that time, division 1 was operating 12 flights.

The short-term air traffic control system detected a violation of separation between the two aircraft and issued a warning signal. The on-board collision warning system also issued a warning. The air traffic controller immediately issued instructions for the two aircraft to change course to avoid the violation of horizontal separation.

Immediately after the incident, the air traffic control crew reported it. The Southern Air Traffic Management Company temporarily suspended the relevant air traffic controllers and conducted an investigation into the incident, as well as reported to the competent authority as prescribed.

Upon receiving the information, Vietnam Air Traffic Management Corporation decided to establish an internal investigation team led by the Head of the Quality Safety Department to clarify the cause of the incident.

Source: https://tuoitre.vn/khong-luu-nham-so-hieu-chuyen-bay-2-may-bay-vi-pham-phan-cach-an-toan-20240621212257486.htm