Description

On 16 December 2002, a Saab 340 being operated by Swedish airline Skyways and arriving at Stockholm on a scheduled domestic passenger flight and an Embraer 145 being operated by Swiss on a scheduled passenger flight from Stockholm to Basel almost collided at the intersection between taxiways ‘Z’ and ‘A’ in normal night visibility. Upon seeing the Saab approaching on a conflicting track, the Embraer 145 was stopped very suddenly and the other aircraft passed within an estimated 3 metres. No persons were injured and neither aircraft was damaged. The diagram below taken from the official report shows the intersection involved.

Investigation

An Investigation was carried out by the Swedish Accident Investigation Board. It was found that the Saab 340 had failed to stop at its acknowledged clearance limit - to Taxiway ‘A’ only and that only prompt action by the Embraer crew had avoided a collision. The Aircraft commander of the Saab had been aware that his aircraft was only cleared to taxiway ‘A’ and it was therefore apparent that the error was involuntary and without his awareness. The co pilot in the Saab who was acting as PM was reportedly “occupied with the shutdown of the left-hand engine” and first became aware of the situation when the (aircraft commander) applied the brakes after passing the Embraer.

The Investigation noted that aircraft ground movement control is shared between two controller positions, GND NORTH and GND WEST and that this means that crews often have to change ground frequency. According to the Investigation findings: