Incident
at THUNDER BAY ON (CYQT)
(Conflict - potential, Conflict - loss of separation, ATS operating irregularity)
The Primac Air Courier Cessna 208 aircraft (C-GIKN) was on an IFR flight from Sault Ste. Marie Airport (CYAM) to Thunder Bay Airport (CYQT). The Ministry of the Solicitor General Pilatus PC-12 aircraft (C-FOPD) was departing on an IFR flight from Thunder Bay Airport (CYQT) to Lake Simcoe Regional Airport (CNB9). C-GIKN was inbound and the pilot received a clearance to descend to 4,400 feet, estimated to arrive at 1155Z. The flight crew of C-FOPD were cleared to depart and initially maintain 3,400 feet. Once C-FOPD was radar identified with sufficient radar separation (five (5) miles), the aircraft was cleared to maintain FL250. However, radar separation began to deteriorate at 11:51:48Z to 3.52 miles and was re-established to the required separation standard of five (5) miles at 11:53:44Z. Ops. impact -- unknown. The 1100Z weather at Thunder Bay Airport was: ceiling broken at 2,600 feet AGL with visibility 15 SM in light snow. The 1200Z weather observation at Thunder Bay Airport was: few clouds at 2,600 feet; visibility of 15 SM.
Supplemental information from T.S.B. Initial Notification (#A02C0239): The PRIMAC AIR Cessna Caravan C-GIKN was inbound to Thunder Bay (estimating at 0655 EST) from Sault Ste. Marie and was cleared to descend to 4,400 feet. The ONTARIO PROVINCIAL POLICE Pilatus PC-12 C-FOPD departed Thunder Bay at 0651 EST for Lake Simcoe Regional Airport. On initial contact (0651 EST) with air traffic control, C-FOPD was cleared to maintain 3,400 feet. C-FOPD was subsequently radar identified and, as the required separation (between C-FOPD and C-GIKN) of 5 NM existed, C-FOPD was further cleared to maintain FL250. During the climb, separation between the two aircraft decreased to 3.4 nautical miles. It was reported that the En-route Controller momentarily confused the terminal separation requirement of 3 NM with the en-route requirement of 5 NM.