Initial information from T.S.B. Initial Notification (#A99O0237): Upon arrival at Toronto (LBPIA), the Boeing 737 aircraft was taxiing to gate C25 at Terminal 3. During the auxiliary power unit (APU) start-up, the flight crew detected a rapid rise in the exhaust gas temperature (EGT). The ground crew advised the flight crew that smoke was visible from the APU exhaust and they deployed the fire bottle. ERS were dispatched as a precaution. Maintenance determined that there was no fire, however, the APU was replaced. 93 S.O.B. -- six (6) crew; 87 passengers. The aircraft was on a scheduled IFR flight from Edmonton to Toronto.

CDN952 B737 was enroute Vancouver to Edmonton 120 NE VR at FL270, lost pressurization and made an emergency descent to 10,000. Once below 10,000 returned to Vancouver. Crew 6, Passengers 29 - Fuel 10,000lbs. Landed at 1512Z on runway 26 without further incident.

Enroute Edmonton to Toronto, overhead the Wiarton VOR, the pilot reported a medical emergency - there was a very sick person on board. The aircraft landed at Toronto at 2030Z. Ops. Impact -- unknown.

While on approach for runway 24R, the crew received a TCAS Resolution Advisory (RA). The crew retarded the throttles to descend but the target disappeared. Toronto ATC advised that there was no traffic in the area. The flight crew continued the approach and landed without further incident. Ops. Impact -- unknown. From a TSB Initial Notification.

The B737 reported a birdstrike while departing Runway 08. A runway inspection was done - nothing found.

Approximately 25NM west of Toronto, CDN952 started a descent to 7,000 feet, coming within two to three (2-3) miles and 300 feet of ONT234. CDN952 had not been given a descent to 7,000 feet. ONT234 was at 12,000 feet and CDN952 had been given and reported level at 13,000 feet. Ops. impact -- none.

A320 CDN952 & A320 ACA111 - OPERATING IRREGULARITY OCCURRED BETWEEN BOTH A/C. CDN952 WAS ENROUTE YEG TO YYZ VIA YEGT468 AT FL370. ACA111 WAS ENROUTE YUL TO YVR VIA DIRECT MW DIRECT XH AT FL370. WHEN A/C WERE APPROX 20 MILES OPPOSITE DIRECT, CONTROLLER TURNED BOTH A/C 30 DEGREES AND DESCENDED ACA111 TO FL350. A/C PASSED APPROX 1-2 MILES LATERAL SEPARATION AND APPROX 1800' VERTICAL. TIME = 1656Z.