Airprox Serious incident Boeing 777-F1B B-2072, Thursday 14 March 2024

You can contribute by submitting additional or updated information.

Date:	Thursday 14 March 2024
Time:	04:00 UTC
Type:	Boeing 777-F1B
Owner/operator:	China Southern Airlines
Registration:	B-2072
MSN:	37310/770
Year of manufacture:	2009
Engine model:	General Electric GE90
Fatalities:	Fatalities: 0 / Occupants:
Other fatalities:	0
Aircraft damage:	None
Category:	Serious incident
Location:	near Mithi - Pakistan
Phase:	En route
Nature:	Cargo
Departure airport:	Guangzhou Baiyun International Airport (CAN/ZGGG)
Destination airport:	Riyadh-King Khalid International Airport (RUH/OERK)
Investigating agency:	AAIB Pakistan
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
China Southern Airlines flight CZ5237, a Boeing 777-F1B, was involved in a serious airprox incident with a Pakistani fighter jet.

Flight CZ5237 was in cruise on ATS Route A325 at FL320 when a Pakistani Air Force aircraft formation of 3 fighters were cleared to the Bholari training area from PAF Base Bholari up to FL300.
Bholari flying areas were active up to FL400 in coordination with Area Control Centre (ACC) Karachi (East). Only Uniform South area was restricted by ACC Karachi (East) for Military traffic from FL100 to FL300, as civil traffic CZ5237 was transiting through the active areas of Bholari maintaining FL320.

Although CZ5237 received wradar vectors by ACC Karachi (East) Controller in order to bypass military areas, one fighter aircraft climbed to FL322 and came in close proximity.
As a result, CZ5237 climbed on TCAS-RA activation up to FL329. At the time of occurrence, 400 ft vertical separation and 1.7 NM lateral separation existed between the two aircraft.
CZ5237 continued to its destination without any further incident.

Cause
1. Unauthorized climb by PAF fighter aircraft beyond the restricted FL300.

Contributory Factors
1. Due to unserviceability of direct speech circuit between Karachi ACC (East) and Bholari, proper coordination could not be done in timely manner.
2. Intermittent R/T communication between ACC Karachi (East) and CSN5237.

Accident investigation: