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Why has Blue Bay been suppressed? 1) HOW WAS THE BLUE BAY PROCEDURE WORKED OUT? The landing procedure on runway 22 consisted of a standard circling approach - an ILS let down on runway 04 followed by a visual manoeuvring with prescribed tracks: opening to the right then left-hand downwind and then final turn to the left. The minima for this procedure was for Category C of 1120 feet and 3700 meters. 
It is evident that in these conditions that no takeoff on runway 22 could take place as long as an aircraft was in procedure and was not completely touched down. Indeed, it was necessary to take into account the possibility of a missed approach before being able to authorize the following plane to carry out the procedure. Consequently the landing rate was limited to one airplane every 10 minutes: 6 arrivals per hour.With the average demand at the Nice airport being between 20 - 24 arrivals per hour, this provoked an important disorganization of air traffic with repercussions on the adjacent En Route Control Centres (Aix-en-Provence and Milan) and the neighbouring airports (Toulon, Marseille, Genoa) which received a large number of diversions. Without counting, of course, the consequences on the management of air terminals and the inconvenience to passengers. The weather conditions when in a 22 configuration, i.e. mistral conditions, usually offer ceiling visibility sufficiently superior to the minima required. Therefore it was a shame not to profit by these conditions to improve the capacity of the airport. This is the reason for contriving the Blue Bay procedure. The "Blue Bay" procedure has the same nominal trajectory as the standard circling approach, the difference being the altitude imposed in downwind (2500 feet) that was going to allow authorizing take-offs at 1000 feet below the arrivals. Of course, minimal meteorological conditions were necessary for the implementation of this procedure: 2500 feet ceiling, 6 km visibility. Below these values, standard circling approach was used. 2) WHY HAS IT BEEN SUPPRESSED? The first version of this procedure - which was not yet called "Blue Bay" - proposed a cruising of 500 feet lower than that indicated on the figure below: the arrivals were limited to 2000 feet and the departures to 1000 feet. 
Outbound aircraft were observed to be above an altitude of 1000 feet to begin with, due essentially to the delicate control of the machine at this stage of the flight. In fact the sequence of take-off for aircrafts A320, B737 or others, was flown at a marked pitch from rotation and also an important induced rate of climb. The aircraft found itself at 1000 feet while the sequence of takeoff was not ended. It often exceeded this altitude.Following the requests to remedy this situation, the crossing altitude was raised to 500 feet, as indicated on the figure above, departures being limited to 1500 feet instead of 1000 and arrivals being limited to 2500 feet instead of 2000. The problem of exceeding the altitude on takeoff was mostly solved, the rare remaining overshootings were more due to human error than problems of machine control. Then many transgressions of downwind altitude of 2500 feet appeared to an alarming degree: about twenty were recorded each year, with comparison to the configuration 22 occurrences (10 % of time on average), which amounts to approximately 1 case for every 500 arrivals. This rate is unacceptable in terms of air transport safety. Fortunately, none of these transgressions resulted in Airprox. The phenomenon were nevertheless analysed and seriously taken under consideration and numerous measures were taken to improve the safety of this procedure: - identification of the procedure under the name of "Blue Bay" ; - reinforcement of the information of a mandatory "maintain 2500 feet" in the aeronautical publications; - reinforcement of the phraseology ; - publication of an addendum "Nice specifications" in the aeronautical documentation ; - traffic information of the type "take-off in progress 1000 feet below" ; - formal adoption, with approval by users, of a tolerance of tailwind component equal to 6 kts in order to use 04 runway as long as possible ; - return report on each incident ; - switch off of NI glide path when procedure 22 is in force so that pilots are not induced to descend below 2500 feet ; - creation of a specific denomination for "abeam runway 22 threshold" as an intersection published in the aeronautical documentation (RESKO) ; - publication of a vertical profile of the procedure with top of descent from 2500 feet at the newly created waypoint ; - at the control tower, implementation of a system that would alert the controller when an airplane did not respect the altitude of 2500 feet (APW). All these measures have had a limited impact on the rate of occurrence of altitude transgressions. Safety problems have continued. This is why the civil aviation services decided to implement a new procedure in which the crossing of arrivals and departures was suppressed. This is the Saleya Procedure. A second reason - of safety also - motivated the implementation of Saleya. When the minimal weather conditions necessary to execute Blue Bay were not achieved, the standard circling procedure was used. Now, at the time of the execution of this procedure, numerous pilots were tempted to descend below the minimum altitude and therefore found themselves in safety conditions not compatible with the safety demands for air transport. Particularly this was observed from the last turn at 500 feet, with low clouds sometimes masking the relief such as Mont Boron (653 feet). |
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