May 21, 1999

Incident at MONTRÉAL / PIERRE ELLIOTT TRUDEAU INTL QC (CYUL) (TCAS alert)

Two aircraft: ICN2205 (F28), IFR from Halifax (CYHZ) to Ottawa (CYOW), and HLA608 (A124), IFR from Toronto (CYYZ) to Gander (CYQX). While at FL280 100 NM east of Dorval (CYUL) near the Beauce (St-Georges) VOR (VLV VOR), ICN2205 (F28) informed the controller that it had received a TCAS alert and was pulling up. The traffic ahead was HLA 608 at FL270. On initial contact, the two aircraft confirmed that they were in straight and level flight at the respective flight levels. No loss of separation. Deux aéronefs: ICN2205 (F28), IFR en provenance d'Halifax (CYHZ) vers Ottawa (CYOW) et HLA608 (A124), IFR en provenance de Toronto (CYYZ) vers Gander (CYQX). Alors qu'il était au FL280 et à 100nm à l'est de Dorval (CYUL), près du VOR de Beauce (St-Georges) (VLV VOR), ICN2205 (F28) a informé le contr,leur qu'il avait reçu une alerte du système d'averstissement et d'évitement d'abordage (TCAS) et qu'il effectuait une remontée. Le trafic devant lui était HLA 608 à FL270. Les deux aéronefs, sur contact initial, ont confirmé être en palier à leurs niveaux de vol respectifs. Aucun manque d'espacement.

January 3, 1999

Incident at Northwest of Saint John NB

ICN2205 ATR43 enroute Halifax to Montreal FL180. ICN2243 ATR43 enroute Saint John to Montreal FL160 requesting FL180. At time of occurrence, both aircraft were proceeding direct Millinocket (MLT) ICN2243 ahead of ICN2205 by aprx 7.5 miles, 20 knots faster was given clearance to climb with a speed requirement. ICN2243 then turned northerly towards Houlton then gradually turned back towards Millinocket When ICN2243 reported at FL180 the speed restriction was restated. At the time of handoff to Boston ATC, ICN2243 had continued the turn and was tracking westerly 255-270 degrees and the spacing between ICN2243 and ICN2205 was decreasing. The Controller issued a descent instruction to FL160 to ICN2243 three (3) times before the aircraft left FL180. A turn of 30 degrees right was issued to ICN2205. Aircraft were aprx 5 miles apart. TSB case closed. Update: The separation between the two aircraft deteriorated to 4.7 miles horizontal where 5 miles horizontal or 1000 feet vertical is required. Separation was restored when ICN2243 descended to 16,000 feet and ICN2205 was instructed to turn 30 degrees right. The operator will have further information for TSB.