Incident at CALGARY INTL AB (CYYC) (Conflict - loss of separation, ATS operating irregularity)


2003-03-24: ACA 222, a B767, was inbound to Calgary from Vancouver and when the flight was approximately 12 NM southwest of YYC, ACA 222 came within 600 feet and 2 NM of a BAe 31 that had departed YYC for Glacier Park in Montana. The required standard in this area is either 3 NM or 1,000 feet. ACA 222 was at 10,000 feet asl intending for Runway 28 and had been inadvertently cleared to 8,000 feet by the Controller. The BAe 31 had departed from Runway 25 heading south and had been cleared to 9,000 feet. As ACA 222 showed leaving 9,800 feet in descent, the Controller queried the crew of their altitude and realized that the clearance had been given in error. He moved the aircraft behind the departing traffic, but less than the required separation already existed. Traffic was passed to ACA 222 and the crew reported it in sight. No TCAS was reported by either aircraft and besides the Controller's instructions, no evasive action was taken by either aircraft.
2003-03-25: UPDATE TSB reported that the Air Canada 767-300, operating as ACA 222, was cleared by the Calgary Arrival Controller to maintain 8,000 feet. The Flight-Ops International Jetstream 31 had departed Calgary and was level at 9,000 feet as assigned by the Departure Controller. The Arrival Controller noticed a conflict as ACA 222 descended through 10,000 feet, and vectored ACA 222 to pass behind the Jetstream. Separation was reduced to 2 nm horizontally and 600 feet vertically in an area where 3 nm or 1,000 feet is required. ACA 222 reported the Jetstream in sight and no TCAS RA manoeuvres were performed.
2003-03-26: UPDATE ANS and Airspace reported that Nav Canada will hold an Operational Safety Investigation concerning this occurrence.


CADORS Number 2003C0362
Occurrence Type Incident
Reported By NAV CANADA
Occurred At 2003-03-22 - 01:20
Day or Night? Day-time
Fatalities 0
Aerodrome ID CYYC
Geographic Location Alberta, Canada, North America, Prairie and Northern Region, 12 NM SW of Calgary
TSB Occurrence Number A03W0055
TSB Class of Investigation Class 5
AOR Number 28257
Reported By NAV CANADA
Categories Airprox/TCAS alert/loss of separation/(near) midair collisions,ATM/CNS
Events Conflict - loss of separation,ATS operating irregularity

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