ACR MLG HAD TO MAKE A GAR FROM AN IAP ILS APCH BECAUSE THE PROCEEDING ACFT WAS SLOW TO START TKOF AND SPACING WAS INADEQUATE.

Narrative

WHILE MAKING AN APCH TO RWY 29L AT MSP IN A SNOW STORM; WE WERE INSTRUCTED TO MAKE A MISSED APCH; SINCE THE ACFT ON DEP IN FRONT OF US HAD STARTED ITS TKOF ROLL TOO LATE FOR US TO SAFELY LAND. OUR INITIAL HDG WAS GIVEN TO US AS 290 DEGS; THEN WE WERE TOLD TO CONTACT DEP CTL; WHO GAVE US A SWESTERLY HDG TO 220 DEGS. ALTHOUGH WE WERE NOW BACK ON INSTS; OUR TCASII DISPLAY SHOWED US TO BE RAPIDLY CLOSING IN ON THE DEPARTING ACFT. DEP CTL SUBSEQUENTLY TOLD US TO TURN R 'IMMEDIATELY'; A TURN WE COULD 'SEE' ON TCASII WOULD TAKE US DANGEROUSLY CLOSE TO THE DEPARTING ACFT. AT THE TIME; WE ENTERED VISUAL CONDITIONS AND COULD VISUALLY CONFIRM THE DEPARTING ACFT WAS TO OUR R; IN THE DIRECTION DEP ORDERED US TO TURN. I REFUSED THE TURN. DEP THEN TURNED US L; WE DID SO. WE THEN MADE A ROUTINE APCH AND LNDG. I BELIEVE THE FOLLOWING TO A SYNOPSIS OF THE EVENTS: THE ORIGINAL MISSED APCH WAS CAUSED BY THE LATE DEP OF THE ACFT IN FRONT OF US. OUR ACFT (A WDB) CLOSED ON THE DEP ACFT (A MLG) MUCH MORE RAPIDLY THAN ATC ANTICIPATED. THE RAPID CLOSURE RATE CREATED A POTENTIALLY HAZARDOUS CONDITION. TCASII HELPED US IN REJECTING THE TURN THAT WOULD HAVE PUT US VERY CLOSE TO THE DEPARTING ACFT.