The Aircraft Accident Investigation Board of Norway issued its final report explaining how confusion between two aircraft with similar call signs resulted in a near-collision at Oslo Airport in October last year. The incident occurred as a Norwegian Air Shuttle Boeing 737-800 (NAX 741) executed a missed approach as another of the company’s aircraft (NAX 740) was taking off.
The crew of NAX 741 experienced a strong tailwind during arrival and failed to stabilize the aircraft on final approach by 1,000 feet agl. The decision to initiate a missed approach was made late in the arrival and was unexpected by either the final or tower controller. Visibility conditions made visual separation from the tower impossible as both aircraft began climbing toward each other.
The tower controller told NAX 741 (the go-around aircraft) to head west. A mix-up of call signs led NAX 740 (the departing aircraft) to execute those instructions and brought the two aircraft to within less than a quarter of a mile laterally with just 500 feet of vertical separation.
The English summary of the Norwegian report did not indicate whether the controller used the wrong call sign or the pilots mixed them up.