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Annual Safety Review 2014
Emerging Issues
PAGE
138
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The risk assessment conducted using the ARMS
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method concluded that the risk to civil aviation is
high and indicates the need for mitigating measures in order to reduce risk to an acceptable level.
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Aggravating factors to the increase in safety risk are the lack of situation awareness of civil Air Traffic
Control (ATC) units and of civil aircraft, and the increased complexity of the airspace due in particular
to new operational concepts (e.g. free route airspace).
On the basis of the technical investigation, the Agency made eight recommendations designed to support risk
reduction associated with this type of occurrence. In addition, the issue of safety occurrences involving civil and
non‑cooperative military traffic has been recently discussed at the ICAO fora, the European Air Navigation Plan‑
ning Group (EANPG) and the High‑Level Safety Conference (HLSC). These discussions resulted in two additional
conclusions addressed to Contracting States that emphasise the need to enhance civil‑military coordination so
as to effectively mitigate the identified safety risk. The Agency fully agreed with these two conclusions as it con‑
siders that they support the actions required to mitigate the safety risk.
Technical Investigation on Radar
Detection Losses in June 2014
On the 5th and 10th of June 2014, occurrences documenting the loss of radar from ATC displays in central Europe
were reported. The affected ACCs were located in Vienna, Prague, Bratislava, Karlsruhe, Munich, Warsaw and Bu‑
dapest. This loss of radar caused capacity to be reduced in some of the affected ATC sectors, the introduction of
flow measures, and in delays. As these types of events may also have a serious impact on safety, EASA was man‑
dated by the Commission to perform a technical investigation and propose recommendations.
The aim of the technical investigation was to better understand the events from a technical point of view, to ex‑
plain what occurred, to assess the impact on safety and to evaluate the need for enduring preventative actions.
The Agency commenced the technical investigation by first obtaining the factual information and collecting
a consistent set of data from the safety investigation authorities, ANSPs and NSAs of the affected Member States,
the Network Manager and other industry stakeholders.
The results of the investigation led the Agency to conclude that:
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The source of the interference was a system or installation, which over‑interrogated the transponders
on board aircraft and in so doing interrogated two specific transponders types, Honeywell TRA-67A
and Rockwell Collins TDR-94D, at rates both beyond their requirements and beyond design limits;
22 ARMS (Aviation Risk Management Solutions) method for Operational Risk Assessment (ORA).