Airprox between Alitalia AZA116 and Condor CFG869 North of Aosta (D-AICI)

Incident Overview On 9 February 2003, at 13:45 UTC, an airprox occurred north of Aosta between Alitalia flight AZA116, an Airbus 319 registered I-BIME, and Condor flight CFG869, an Airbus 320 registered D-AICI. The Alitalia aircraft was operating from Milan Malpensa to Amsterdam, while the Condor aircraft was en route from Palma de Majorca to Erfurt. ## Sequence of Events At 13:33 UTC, Condor CFG869 contacted Swiss radar on the Geneva MS3 sector frequency of 126.05 MHz and was cleared on route IRMAR–KINES–DITON at flight level 300. At 13:42 UTC, Alitalia AZA116 reported on the same frequency and was cleared to climb to flight level 290. The pilot acknowledged the clearance. At 13:45 UTC, the radar controller informed the Alitalia pilot that a higher-level clearance would be issued after flying 15 NM due to traffic 1,000 ft above. One minute later, the controller observed that the Alitalia aircraft had climbed above its authorized flight level. The controller instructed the Alitalia pilot to make a 30-degree right turn, instructed the Condor pilot to climb to flight level 310, and instructed the Alitalia pilot to descend immediately to flight level 280. ## Separation and Alerts According to the radar plot, the minimum distance between the two aircraft was a lateral distance of 3.4 NM and an altitude difference of 400 ft. The STCA alarm tripped at 13:45:57 UTC. The Alitalia pilot reported a TCAS TA alert but no resolution advisory, and stated that visual contact was made after the alert. The Condor pilot reported only a TCAS TA alert without a resolution advisory. ## Findings The control frequencies of sector MS3/MA3, 126.05 MHz and 132.315 MHz, were coupled. The radar controller in charge was a trainee controller under the direct supervision of an instructor. All radiotelephone exchanges were conducted in English. The traffic load was average, with eleven aircraft in contact on the sector frequency. The incident occurred under visual meteorological conditions. The wind at flight level 300 was from 330 degrees at 55 knots. ## Analysis The Alitalia pilot reported that he selected flight level 300 instead of the cleared flight level 290. The controller's response, including the turn instruction, vertical separation instructions, and essential traffic information, was described as logical and effective. The controller's actions increased the crossing distance from 2.7 NM to 3.4 NM and prevented TCAS resolution advisories from being activated. The prior information about the delayed higher-level clearance was not sufficient to alert the Alitalia pilot to the traffic above.