Description

On 21 August 2010, an ATR72-200 being operated by Golden Air on scheduled passenger service from Stockholm Bromma to Ängelholm and a Jetstream 32 being operated by the AIS Airlines, a Dutch professional pilot training organisation from Jönköping to Stockholm Bromma received and responded to co-ordinated TCAS RAs in day Visual Meteorological Conditions (VMC). Controller intervention during the RA response was ignored. The location of the conflict was approximately 30 nm north-east of Jönköping.

Investigation

An Investigation was carried out by the Swedish AIB using ATC recordings and an interview with the controller. It was established that traffic in the area, which was under the control of Stockholm ACC, was light and that the usual en route separation standard of 5nm horizontally or 1000 feet vertically was prescribed in the Class ‘C’ airspace where the conflict occurred.

The experienced controller involved was found to have cleared the Jetstream to climb to FL150 after forgetting that the opposite direction ATR72 was at FL140 and would conflict. She had then become distracted when turning away from her radar screen in order to arrange the hand-off of the Jetstream and a second aircraft to another sector being controlled from an adjacent position in the same ACC.