NMAC OVER APCH END OF ACTIVE RWY BTWN A METRO LINER AND A SHORTS 330. METRO DIVED IN TAKING EVASIVE ACTION.

Narrative

WE WERE CLRED FOR A VISUAL APCH TO YVR RWY 26. WE WERE GIVEN FIRST A SPD REDUCTION TO 180 KTS OR LESS ABOUT 15 MI OUT AND THEN TOLD TO 'KEEP THE SPD UP' TO THE OM AT ABOUT 8 MI OUT. A (ACR Z) 747-400 WAS CLRED FOR TKOF WHILE WE WERE ON ABOUT 5 MI FINAL. AS WE DSNDED THROUGH ABOUT 300 FT AGL; THE 747 JUST BEGAN HIS TKOF ROLL. I DECLINED THE LNDG CLRNC AND REQUESTED A CIRCLE TO RWY 12. A SHORT SD-330 WAS OVERHEAD THE APCH END OF 26 AT 6-700 FT ON L TFC FOR 12 AND AS WE INITIATED THE GAR WE PASSED ABOUT 100 FT BELOW HIM AS I DID A FAIRLY HARD PUSHOVER WHEN I SAW HIM XING FROM OUR L TO R. TWR CALLED AND VERIFIED THAT WE SAW HIM AND SAID WE WERE TOLD TO MAINTAIN 500 FT. NEITHER THE CHK AIRMAN IN THE R SEAT OR MYSELF REMEMBER HEARING THE ALT RESTR GIVEN TO US. OUR MAX ALT WAS ABOUT 600 FT. CONTRIBUTING FACTORS: CANADIANS ALLOW 2 ACFT ON THE RWY SIMULTANEOUSLY HAVING ACFT GOING TO 1 RWY OPERATING IN THE APCH/MISSED APCH CORRIDOR FOR ANOTHER RWY CLRING A HVY JET FOR AN IMMEDIATE TKOF WITH MINIMAL SPACING. HVY JETS DON'T EXPEDITE. IF WE HAD LANDED ON 26 WE WOULD HAVE FLOWN THROUGH JETWASH OF A 747 AT TKOF THRUST IN OUR METROLINER. I BELIEVE THIS COULD EASILY LEAD TO LOSS OF CTL OF THE ACFT. MY LACK OF EXPERIENCE IN THE TYPE OF ACFT FLOWN. MUCH OF MY ATTENTION DURING THE GAR MANEUVER WAS DIRECTED INSIDE THE ACFT. TRYING TO WORK TOO MANY ACFT INTO TOO LITTLE TIME LEADING TO 'SPD UP-SLOW DOWN' APCHS AND IMMEDIATE TKOFS. WE TELEPHONED THE TWR AFTER LNDG AND THEY CONSIDERED IT NO BIG DEAL.