Incident at TORONTO / LESTER B. PEARSON INTL ON (CYYZ) (ATS operating irregularity)


1997-09-03: MES3113 SAAB FAIRCHILD 34 MESABA AIRLINES TSC440, inbound to Toronto (LBPIA), was instructed to descend and maintain 17,000 due to same direction traffic (MES3113) at 16,000. As TSC440 approached 17,000, it appeared that the aircraft leveled, then continued to 14,000 and then began to climb. The controller did not see TSC440 break his altitude due to deviations causing extra workload and, when he became aware, instructed TSC440 to level off the climb at 15,000. The pilot of TSC440 advised via telephone that they were assigned 17,000 and had set the autopilot to 17,000. As they approached the altitude, they had a TCAS warning so they disconnected the autopilot, levelled at 17,000 and when the TCAS was clear, continued the descent. Separation was reduced to one mile lateral as TSC440 passed abeam MES3113. The controller had passed traffic previously and MES3113 had visual contact with the L-1011. A (NAV CANADA) occurrence report will follow. Ops. impact -- unknown.


CADORS Number 1997O0238
Occurrence Type Incident
Reported By NAV CANADA
Occurred At 1997-05-15 - 14:00
Day or Night?
Fatalities 0
Aerodrome ID CYYZ
Geographic Location Ontario, Canada, North America, Ontario Region, Toronto, Ontario (40nm NE)
TSB Occurrence Number
TSB Class of Investigation
AOR Number
Reported By NAV CANADA
Categories Airprox/TCAS alert/loss of separation/(near) midair collisions,ATM/CNS
Events ATS operating irregularity

Aircraft Details (1 aircraft)

Type Aeroplane
 Silhouette image of Aeroplane
Canadian Registration
Foreign Registration
Country of Registration Canada
Occurrence Type Incident
Operator AIR TRANSAT Commercial
Make  Silhouette image of LOCKHEED
Model L 1011
Year Built
Engine Type
Engine Make
Engine Model
Gear Type Land
Private No
Amateur Built No
Flight Number TSC440
Flight Rule
CARS Subpart
Phase of Flight Descent
Damage Unknown
Fatalities 0
Injuries 0
Events TCAS alert

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