AT 60 KNOTS DURING TKOF ON MIA RWY 27L AN ACR IS TOLD TO REJECT HIS TKOF AT THE SAME TIME AN ARRIVAL ON RWY 30 WAS TOLD TO GAR. THE GAR ACFT PASSED OVERHEAD WITH LESS THAN 400 FT SEPARATION.

Narrative

MIA TWR CLRED US INTO POSITION AND HOLD ON RWY 27L. AFTER ABOUT 15 SEC WE WERE CLRED FOR TKOF. AS WE APCHED THE INTXN OF RWY 30 WE WERE TOLD TO ABORT OUR TKOF AT THE SAME TIME THAT ANOTHER B737 WAS TOLD TO GAR FROM ITS APCH TO LAND ON RWY 30. THAT ACFT OVERFLEW OUR ACFT AT THE INTXN OF RWY 27L AND RWY 30 AT WHAT I WOULD GUESS TO BE ABOUT 300 TO 400 FT. SUPPLEMENTAL INFO FROM ACN 547939: WE WERE TOLD TO ABORT AT ABOUT 60 KTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE WX WAS CLOUDY WITH RAIN; THUNDERSTORMS TO THE W AND A CEILING OF APPROX 1000 FT. THERE WAS NO MAJOR FREQ CONGESTION. THE TWR WAS CTLING DEPARTURES ON RWY 27L AND ARRIVALS ON RWY 30. THE N RWY WAS APPARENTLY UNDER THE CTL OF SEPARATE CTLR. THE RPTR FINDS THIS CONFIGURATION TO BE THE USUAL ONE WITH 90 PERCENT OF THE ARRIVALS FROM THE S USING RWY 30. THE TFC LEVEL AT THE ARPT WAS BUSY WITH FOUR OR FIVE DEPARTURES WAITING TO TKOF AND AN UNKNOWN NUMBER OF ARRIVALS. THE TKOF CLRNC WAS GIVEN WITH A 'WITHOUT DELAY' COMMENT. THERE WAS NO TFC ADVISORY GIVEN WITH THE CLRNC. THE RPTR SAID THAT THEY WERE NOT ON TWR FREQ LONG ENOUGH TO HEAR THE ARRIVING TRAFFIC'S LNDG CLRNC. ADDITIONAL INFO FROM ACN 547939: THERE WAS A 10 TO 15 SECOND DELAY IN TKOF DUE TO ADJUSTMENT AND CHANGE OF TKOF THRUST POWER SETTING BECAUSE OF THE CONCERN ABOUT THE WX IN THE DEPARTURE AREA. DURING TAXI BACK FOR THE SUBSEQUENT DEPARTURE OPS AT THE ARPT WERE SUSPENDED FOR 20 MINS DUE TO A TORNADO WARNING. ADDITIONAL INFO FROM ACN 547981: THE RPTR CALLED BACK INDICATING THAT HIS COMPANY REVIEW TEAM HAD FOUND OUT FROM ATC QUALITY ASSURANCE THAT THERE WAS TRAINING IN PROGRESS AT THE TIME OF THE INCIDENT AND THE INSTRUCTOR ORDERED THE REJECT AND GAR WHEN THE TRAINEE COULD NOT HANDLE THE SIT. THERE WAS FOUND TO BE NO CONTRIBUTION TO THE ERROR BY EITHER CREW.