DEPARTING AND ARRIVING planes came within 800 metres of each other in near-miss incident at Dublin Airport in March.

The Air Accident Investigation Unit (AAIU) released a report today which outlines how two Boeing 737 airplanes came close to colliding due to a blocked transmission.

Earlier this year on 8 March, Dublin Airport was busy, with a large volume of inbound traffic. The incident occurred just before 10pm when a departing aircraft was cleared for take off as the arriving aircraft was on its final approach to the runway.

The air-traffic controller tried to stop the departing aircraft from taking off after he re-appraised the situation. But a blocked transmission meant that the departing plane didn’t hear the order.

There were over 300 passengers on both airplanes.

Identify the gap

The air-traffic controller’s job was to identify a suitable gap in the arriving schedule to facilitate a departure. When he saw a moment, he instructed the departing aircraft to take off.

However, the arriving aircraft “seemed to slow down” as it was arriving, which made the controller change his mind. He instructed the departing flight to stay on the runway.

But the departing flight didn’t get this instruction and as it passed the stop line, the controller decided it was safer to let the arriving aircraft land rather than make it stop.

The planes came within 807 metres of each other at their closest point.

Good communication essential

The report outlines how good communication is essential to avoid dangerous incidents happening.

“Good communications are essential to the safe and orderly flow of air traffic,” reads the report.

“With traffic levels building up at that particular time of the evening, increased coordination was necessary between the Air Movements Controller and the Approach Controller in order to identify gaps for departing traffic.”

After the incident, the Irish Aviation Authority installed a ‘Time to Touchdown’ facility (TTT) for the Tower Controller (AMC) which displays the time to touchdown of the next aircraft on final approach.

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