History of Flight
On 4 May 2025, Air Arabia flight ABY405, an Airbus A320-214 registered A6-AOS, departed Sharjah International Airport at 19:56 UTC for Chhatrapati Shivaji Maharaj International Airport, Mumbai. AeroLogic flight BOX622, a Boeing 777F registered D-AALJ, departed Frankfurt Airport at 14:38 UTC, also destined for Mumbai. Both aircraft were on converging routes and planned to transit the Muscat and Mumbai Flight Information Regions (FIRs) via waypoint PARAR.
Sequence of Events
At 20:07 UTC, Muscat Control relayed an estimate for ABY405 crossing PARAR at 20:57 UTC, maintaining FL350. At 20:36 UTC, Mumbai OCC (North) requested FL370 for ABY405; Muscat Control agreed and coordinated a level change to FL370 with an updated PARAR estimate of 20:58 UTC. However, at 20:58 UTC, ABY405 crossed PARAR at FL350 instead of FL370. At 20:40 UTC, an estimate for BOX622 placed it at PARAR at 21:00 UTC, maintaining FL350. BOX622 crossed PARAR at 21:01 UTC at FL350, traveling approximately 40 knots faster than ABY405.
Loss of Separation
By 21:05 UTC, the Mumbai OCC (North) controller observed that both aircraft were at FL350 with only a 3-minute longitudinal separation, below the required 10-minute standard for same speed and level. The conflict was not immediately detected because the controller was occupied with estimate coordination while the coordinator was on break. No conflict alert was generated.
Resolution
At 21:08 UTC, the controller instructed BOX622 via CPDLC to turn left heading 040, then heading 070 at 21:09 UTC. At 21:12 UTC, BOX622 was directed to descend to FL330, and at 21:14 UTC further to FL310, after which it was cleared direct to waypoint SUGID. Standard separation was restored. Both aircraft continued to Mumbai and landed without further incident.
Injuries and Damage
There were no injuries to any persons. No damage was sustained by either aircraft.