Narrative:

Air carrier X, an medium large transport, landed runway 4R just as air carrier X was touching down. Approach control called me to advise that air carrier Y, a widebody transport, will land on runway 4L. I then advised 2 aircraft who are taxiing (with a clearance to cross runway 4L) to hold short of G. I then instructed air carrier X to turn left off of runway 4L and hold short of runway 4L, or so I thought! Air carrier X then crossed runway 4L with air carrier Y on about a 1/2 mi final. When I questioned air carrier X about his position, he stopped his aircraft right in the middle of the runway so I had to send air carrier Y around. When I reviewed the tape the next morning, I was surprised to hear myself tell air carrier X to 'turn left and hold short of G.' I was thinking one thing yet said another, and didn't catch my mistake! Air carrier X answered with 'roger.' perhaps a full readback would have helped me catch my mistake?

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Original NASA ASRS Text

Title: CTLR INADVERTENTLY APPROVED ACR X TO CROSS RWY WITH ACR Y ON HALF MILE FINAL. ACR Y WAS ISSUED A GO AROUND. OPERATIONAL DEVIATION.

Narrative: ACR X, AN MLG, LANDED RWY 4R JUST AS ACR X WAS TOUCHING DOWN. APCH CTL CALLED ME TO ADVISE THAT ACR Y, A WDB, WILL LAND ON RWY 4L. I THEN ADVISED 2 ACFT WHO ARE TAXIING (WITH A CLRNC TO CROSS RWY 4L) TO HOLD SHORT OF G. I THEN INSTRUCTED ACR X TO TURN LEFT OFF OF RWY 4L AND HOLD SHORT OF RWY 4L, OR SO I THOUGHT! ACR X THEN CROSSED RWY 4L WITH ACR Y ON ABOUT A 1/2 MI FINAL. WHEN I QUESTIONED ACR X ABOUT HIS POS, HE STOPPED HIS ACFT RIGHT IN THE MIDDLE OF THE RWY SO I HAD TO SEND ACR Y AROUND. WHEN I REVIEWED THE TAPE THE NEXT MORNING, I WAS SURPRISED TO HEAR MYSELF TELL ACR X TO 'TURN LEFT AND HOLD SHORT OF G.' I WAS THINKING ONE THING YET SAID ANOTHER, AND DIDN'T CATCH MY MISTAKE! ACR X ANSWERED WITH 'ROGER.' PERHAPS A FULL READBACK WOULD HAVE HELPED ME CATCH MY MISTAKE?

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.