Incident at CALGARY INTL AB (CYYC) (Conflict - loss of separation)

Summary

2003-01-13: UPDATE TSB reported that JZA 8236, was inbound to Calgary and was cleared to maintain 6,000 feet on a vectored approach to Runway 34. ACA 212, was also inbound and cleared to 8,000 feet. ACA 212 turned right to a heading of 160° at HANSI intersection in accordance with the published arrival procedure, which resulted in decreasing separation with JZA 8236. The Controller immediately issued a vector to ACA 212 which would ensure a parallel track to JZA 8236. ACA 212 did not immediately respond, then called to ask if the vector was for them. The Controller then issued another vector with a greater heading change, which was acknowledged by ACA 212. However, ACA 212 did not turn for about 25 seconds, during which time the separation between the two aircraft decreased to 2.82 miles laterally and 700 feet vertically where 3 miles and 1,000 feet is specified.
2003-01-09: JZA 8236, a DHC-8, was inbound to Calgary on J504 and on a vectored approach to Runway 34 and was cleared to maintain 6,000 feet. ACA 212, an A320, was inbound on J504 and cleared to maintain 8,000 feet. At HANSI, ACA 212 turned right to a heading of 160 degrees on the OPALE Five arrival. This resulted in deteriorating separation between the two a/c. Required separation in this area is either 1,000 feet vertical or 3 miles radar. When ACA 212 turned right, there was 5 miles radar separation and 300 feet veertical. The Controller immediately issued a vector to ACA 212 that would parallel the track of JZA 8236. The crew of ACA 212 did not respond to this vector and asked if the call was for them. The Controller then issued another vector to ACA 212 that would result in a tighter turn and would result in separation not being compromised. ACA 212 acknowledged this clearance but the aircraft did not turn for almost 25 seconds. A loss of separation occurred at 2044Z when ACA 212 was still in the turn and their track took them closer than 3 miles radar from JZA 8236 with only 700 feet vertical. Separation was regained at 2044:24 when there was 3 miles radar and 1,000 feet vertical. The closest the 2 flights came to each other was 2.82 miles and 700 feet vertical.

Details


CADORS Number 2003C0029
Occurrence Type Incident
Reported By NAV CANADA
Occurred At 2003-01-08 - 20:44
Day or Night? Day-time
Fatalities 0
Injuries 0
Aerodrome ID CYYC
Aerodrome Name CALGARY INTL AB (CYYC)
Geographic Location Alberta, Canada, North America, Prairie and Northern Region, Calgary Intl
TSB Occurrence Number A03W0005
TSB Class of Investigation Class 5
AOR Number 26916
Reported By NAV CANADA
Categories Airprox/TCAS alert/loss of separation/(near) midair collisions
Events Conflict - loss of separation


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