Narrative:

We were vectored to a left downwind to runway 6L at day. As we approached the approach end of runway 6L approach control cleared us for the visibility. Shortly thereafter we began our left turn to base. Approach control called back and asked us to extend downwind because an light transport was approaching from the west, making a visibility to runway 36. We called the light transport traffic in sight. Approach then reclred us and asked us to keep our turn in tight. Approach then switched us to tower control. Dayton tower then told us that the light transport was making a visibility to runway 6L and not runway 36. We began a climb above and behind the light transport, passing approximately 500' above and 300' behind the light transport. We then were cleared for the visibility to runway 36. Both aircraft landed west/O complications. I called the approach control supervisor and questioned them as to what we were chain of events. I spoke with the radar facility manager. He reviewed the situation with the radar and tower controllers. He advised me that tower was controling the light transport. There was a NORDO aircraft between the light transport and runway 36, so they changed his landing clearance to runway 6L at (supposedly) the same time approach control cleared us for the visibility to runway 6L. Approach control was unaware that the light transport had been cleared to different runway, thus positioning both aircraft on a collision course. I found it extremely hard to understand how tower and approach can both control different aircraft and clear them both for the same runway at the same time. I don't completely understand the communication process between tower and approach, but at best the communication was poor, if not nonexistent. Fortunately the conflict was detected by all and a hazardous situation was avoided.

Related reports:

Google
 

Original NASA ASRS Text

Title: THE MLG WAS CLEARED FOR A VISUAL APCH TO RWY 6L WITH TRAFFIC (LTT) ON FINAL TO RWY 36. MLG HAD THE LTT IN SIGHT. TWR CHANGED THE LTT TO RWY 6L IN FRONT OF THE MLG. MLG WENT AROUND.

Narrative: WE WERE VECTORED TO A LEFT DOWNWIND TO RWY 6L AT DAY. AS WE APCHED THE APCH END OF RWY 6L APCH CTL CLRED US FOR THE VIS. SHORTLY THEREAFTER WE BEGAN OUR LEFT TURN TO BASE. APCH CTL CALLED BACK AND ASKED US TO EXTEND DOWNWIND BECAUSE AN LTT WAS APCHING FROM THE W, MAKING A VIS TO RWY 36. WE CALLED THE LTT TFC IN SIGHT. APCH THEN RECLRED US AND ASKED US TO KEEP OUR TURN IN TIGHT. APCH THEN SWITCHED US TO TWR CTL. DAYTON TWR THEN TOLD US THAT THE LTT WAS MAKING A VIS TO RWY 6L AND NOT RWY 36. WE BEGAN A CLB ABOVE AND BEHIND THE LTT, PASSING APPROX 500' ABOVE AND 300' BEHIND THE LTT. WE THEN WERE CLRED FOR THE VIS TO RWY 36. BOTH ACFT LANDED W/O COMPLICATIONS. I CALLED THE APCH CTL SUPVR AND QUESTIONED THEM AS TO WHAT WE WERE CHAIN OF EVENTS. I SPOKE WITH THE RADAR FAC MGR. HE REVIEWED THE SITUATION WITH THE RADAR AND TWR CTLRS. HE ADVISED ME THAT TWR WAS CTLING THE LTT. THERE WAS A NORDO ACFT BTWN THE LTT AND RWY 36, SO THEY CHANGED HIS LNDG CLRNC TO RWY 6L AT (SUPPOSEDLY) THE SAME TIME APCH CTL CLRED US FOR THE VIS TO RWY 6L. APCH CTL WAS UNAWARE THAT THE LTT HAD BEEN CLRED TO DIFFERENT RWY, THUS POSITIONING BOTH ACFT ON A COLLISION COURSE. I FOUND IT EXTREMELY HARD TO UNDERSTAND HOW TWR AND APCH CAN BOTH CTL DIFFERENT ACFT AND CLR THEM BOTH FOR THE SAME RWY AT THE SAME TIME. I DON'T COMPLETELY UNDERSTAND THE COM PROCESS BTWN TWR AND APCH, BUT AT BEST THE COM WAS POOR, IF NOT NONEXISTENT. FORTUNATELY THE CONFLICT WAS DETECTED BY ALL AND A HAZARDOUS SITUATION WAS AVOIDED.

Data retrieved from NASA's ASRS site as of July 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.