Report on serious incident at Oslo Airport Gardermoen on 31 October 2012, aircraft proximity (AIRPROX) between LN-DYC (NAX741) and LN-NOM (NAX740), both operated by Norwegan Air Shuttle ASA

Aviation report 2013/25 eng

English translation now available. On 31 October 2012, an aircraft proximity (AIRPROX) situation occurred between two aircraft from Norwegian Air Shuttle during a simultaneous missed approach (NAX741) and departure (NAX740) at Oslo Airport. There was a strong tailwind on final. The AIBN believes that the flight crew on NAX741 had unrealistic expectations regarding the possibility of being stabilized no later than at 1000 ft Above Field Elevation (AFE). The decision to initiate a missed approach procedure was taken at a late stage. The expectations of the final controller and tower controller, that the landing speed would be reduced sufficiently during the approach, were not met. The missed approach of NAX741 came into conflict with the simultaneous departure of NAX740.

Visibility conditions were such that the tower controller could not maintain visual separation between the two aircraft. Both were climbing, one after the other. The tower air traffic controller instructed NAX741 to divert west. A mix-up of call signs occurred and led to NAX740 executing the clearance given to NAX741. The minimum horizontal distance between the aircraft was approximately 0.2 NM (370 m) whereas the vertical separation was 500 ft (152 m). It is the AIBN's view that the situation contained a real danger of collision, but once it was a fact, the situation awareness and sound assessments of the flight crews and tower controller prevented a further escalation of the conflict.

The AIBN considers established and practiced procedures to be conductive to recognizing situations and averting them before they become critical. Data from the Cockpit Voice Recorder (CVR) was not secured. CVR data is important to understand the sequence of events, and the AIBN therefore sees it as unfortunate when CVR data is not secured. The AIBN does not promote any new safety recommendation in this report, but refers to a previously issued safety recommendation (SL No 2012/06T), which has not been closed out.

Facts

Location Oslo Airport Gardermoen ENGM
Occurrence date 31.10.2012
ICAO Location indicator ENGM
Aircraft Boeing 737-300/400/500 / Boeing 737-300/400/500
Operator Norwegian Air Shuttle / Norwegian Air Shuttle
Registration LN-DYC/ LN-NOM
Meteorological conditions IMC
County Akershus
Type of occurrence Serious incident
Type of operation Scheduled air transport / Scheduled air transport
Category of operation Heavy, aeroplane (> 10 000kg) / Heavy, aeroplane (> 10 000kg)
Aircraft category Landplane, Multi-engine, Turbofan/Turbojet
FIR/AOR ENOS (Oslo ATCC)