Incident at Thunder Bay, Ontario (ATS operating irregularity)


1996-09-27: An operating irregularity occurred between CDR1331, a FK28, IFR Winnipeg to Thunder Bay and BLS362, a SW4, IFR Sioux Lookout to Thunder Bay. Both aircraft were being radar vectored for straight in ILS approaches for runway 07 circling for runway 12. It was initially planned that BLS362 would be first so he was given descent to 5000' and CDR1331 would follow him and was given descent to 6000'. Both aircraft were on parallel left base legs with BLS362 inside of CDR1331. Approximately 20 miles west of the airport, the plan changed due to the faster speed of CDR1331. CDR1331 was given clearance to 4000' and a turn to intercept the localiser with the instruction to expedite his descent. BLS362 was given a 30 degree turn to the right for spacing. Vertical separation of 1000' was expected prior to encroachment of the 3 miles of radar separation that was required. When it became apparent that the required 1000' vertical separation would not be achieved in time BLS362 was turned a further 15 degrees and CDR1331 was turned 10 degrees to maintain radar separation. The aircraft passed with 800' of vertical separation and 2.13 of radar separation. Controller qualification training was in progress at the time of the operating irregularity.


CADORS Number 1996C0408
Occurrence Type Incident
Reported By NAV CANADA
Occurred At 1996-09-26 - 19:49
Day or Night? Day-time
Fatalities 0
Injuries 0
Aerodrome ID
Aerodrome Name
Geographic Location Ontario, Canada, North America, Ontario Region, Thunder Bay, Ontario
TSB Occurrence Number
TSB Class of Investigation
AOR Number
Reported By NAV CANADA
Categories ATM/CNS
Events ATS operating irregularity

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