The French civil aviation authorities (BEA – Bureau d’Enquêtes et d’Analyses pour la Sécurité de l’Aviation Civile) have closed and released an inquiry on a loss of separation (airprox) incident between an Air France Airbus A319 and a Eurocopter Cougar while flying east of Marseille. In its final report, the BEA rated the near miss (quasi-collision) as a serious incident.
On 27 June 2016 at 15:45 (UTC +2), an Air France Airbus A319 (F-GRHX) operating flight HOP25PG from Bordeaux was performing a visual approach for runway 31R at Marseille-Provence. The Eurocopter Cougar (F-ZWBS) was returning from a VFR flight east of Marseille and descending to 1,500 ft to the aerodrome circuit entry points.
Since the transponder of the helicopter failed during the flight, air traffic control only had primary radar contact. At a certain point, the helicopter was hovering without informing air traffic control and radar contact was lost. The two aircraft crossed each other without the crews having received information about their respective presence.
Visual contact between the crews of both aircraft was established only after crossing each other, the minimum separation between the A319 and the helicopter was 0.19 NM horizontally and 240 ft vertically.
The near-collision results from the combination of the following factors:
- the absence of segregation measures by air traffic control over the Cougar without a transponder, in dense airfield traffic where the compatibility of IFR and VFR traffic is based on traffic information and visual contact between crews;
- non-compliance by the Cougar crew with the altitude of the aerodrome circuit;
- the failure of the Cougar crew to provide information on its hovering and inaccurate position reports which led the controller to construct an erroneous mental representation of the situation and to provide unsuitable traffic information as a consequence;
- the lack of provision of information on the existence of zones of non-visualization of primary radar echoes to the controllers
Contributed to the serious incident:
- the absence of an overall strategy for sequencing VFR and IFR traffic on arrival;
- the workload that did not allow the tower controller to sufficiently anticipate the arrival of the HOP flight;
- excessive flexibility in the management of parallel runways;
- a high occupancy rate of the tower frequency due to traffic density, also favoured by the use of non-standard phraseology, which did not allow the HOP flight crew to intervene and benefit from traffic information in a timely manner;
- possible overconfidence between the tower controllers and the Cougar crew, professionals based on the same platform, which may have led to less rigour in the accuracy of the position reports and their use for the traffic management.
The BEA sent five safety recommendations to DSNA concerning the following aspects:
- spatiotemporal segregation of flights with transponder failure;
- information of the controllers of Marseille-Provence on the restrictions of performances or the limitations of their equipment of visualization and in particular of the primary radar;
- evaluation of the possible extension of this measure to other air traffic organizations;
- implementation of procedures within tower and approach organizations of Marseille-Provence so that flight management is part of a common strategy of traffic sequencing;
- study of the implementation of working methods in Marseille-Provence allowing to sequence the traffic on one or the other parallel runways in complete safety.