Incident Overview
On March 14, 2024, China Southern Airlines flight CSN5237, a Boeing 777-F1B cargo aircraft registered as B-2072, was operating from Guangzhou Baiyun International Airport (ZGGG), China, to King Khalid International Airport (OERK) in Riyadh, Saudi Arabia. While transiting the Karachi Flight Information Region along Air Traffic Services Route A325, the flight experienced a Traffic Alert and Collision Avoidance System (TCAS) Resolution Advisory (RA) due to the proximity of a Pakistan Air Force fighter aircraft.
Sequence of Events
The flight was maintaining flight level (FL) 320 when it entered the vicinity of the Bholari training area, where Pakistan Air Force fighter aircraft were conducting operations. The Area Control Centre (ACC) Karachi (East) controller had provided radar vectors to CSN5237 to bypass active military areas. However, one fighter aircraft climbed to FL322, coming into close proximity with the commercial flight.
As a result, the TCAS on CSN5237 issued a Resolution Advisory, prompting the crew to execute a climb. The aircraft ascended to FL329 in response. At the time of the event, the vertical separation between the two aircraft was 400 feet, and the lateral separation was 1.7 nautical miles.
Aircraft and Operational Details
The involved commercial aircraft was a Boeing 777-F1B, serial number 37310, manufactured in 2010 and powered by GE90-110B1L engines. The flight was a cargo operation. The military aircraft were a formation of three fighters cleared to operate in the Bholari training area up to FL300, though the area was active up to FL400. Only the Uniform South sector was restricted from FL100 to FL300 for military traffic, as CSN5237 transited on its cleared route.
Aftermath
Following the TCAS RA event, CSN5237 continued its flight to Riyadh without further incident. No injuries were reported to any persons on board, and no damage was sustained by either aircraft. Meteorological conditions at the time included no significant weather, with visibility of 5,000 meters and wind from 330 degrees at 8 knots. Communications with Karachi ACC were normal throughout the incident.