TRACON controller described a conflict event when traffic cleared for an approach to runway 34L but ...

Narrative:

Landing runways 34L and 34C; departing on runway 34R. The final for [runway] 34C was getting strung out to about a 20 mile final when a B737 checked on frequency on a west downwind; I advise him of the length of the final for [runway] 34C and ask him if he would prefer a shorter final to [runway] 34L; they replied affirmative and told him to expect [runway] 34L. When I turned the B737 base; I instructed him to report sighting a DH8D landing 34C; eventually he did and I instructed the B737 to maintain visual separation from the DH8D landing [runway] 34C and you're cleared for the visual approach for [runway] 34L. The B737 accepted visual separation and read back visual approach runway 34L. Another air carrier was trailing the B737 and on approach to [runway] 34C; I issued traffic and when the trailing air carrier reported the B737 in sight I instructed him to maintain visual separation; and the B737 was landing [runway] 34L and you; (trailing air carrier); are landing on 34C; all read back correctly; and sent to tower frequency. The B737 flew threw the final for [runways] 34L and 34C and then came back to my frequency saying he's deviating for traffic. Both aircraft go around; and I am instructed to issue the TRACON phone number to the B737. When the captain of the B737 spoke to the operations manager; he said he knew he was cleared for [runway] 34L and read it back; but the copilot (flying the aircraft) had it in his mind he was landing runway 34R and crossed over both finals of 34L and 34C; and lined up for 34R. The captain said he told the co-pilot he was lined up for the wrong runway and tried to adjust; but by that time trailing air carrier had closed the gap and was very close. The B737 didn't tell me; or the tower about this maneuver; so no one knew what he was doing until he came on my frequency announcing his now deviation to the east. When the captain of trailing air carrier called the TRACON he told the operations manager he was going to file a near midair collision.

Original NASA ASRS Text

Title: TRACON Controller described a conflict event when traffic cleared for an approach to Runway 34L but flew through the final for Runway 34L and 34C resulting in a declared NMAC. Pilot error was listed as the causal factor.

Narrative: Landing Runways 34L and 34C; departing on Runway 34R. The Final for [Runway] 34C was getting strung out to about a 20 mile final when a B737 checked on frequency on a west downwind; I advise him of the length of the final for [Runway] 34C and ask him if he would prefer a shorter final to [Runway] 34L; they replied affirmative and told him to expect [Runway] 34L. When I turned the B737 base; I instructed him to report sighting a DH8D landing 34C; eventually he did and I instructed the B737 to maintain visual separation from the DH8D landing [Runway] 34C and you're cleared for the visual approach for [Runway] 34L. The B737 accepted visual separation and read back Visual Approach Runway 34L. Another Air Carrier was trailing the B737 and on approach to [Runway] 34C; I issued traffic and when the trailing Air Carrier reported the B737 in sight I instructed him to maintain visual separation; and the B737 was landing [Runway] 34L and you; (trailing Air Carrier); are landing on 34C; all read back correctly; and sent to Tower frequency. The B737 flew threw the final for [Runways] 34L and 34C and then came back to my frequency saying he's deviating for traffic. Both aircraft go around; and I am instructed to issue the TRACON phone number to the B737. When the Captain of the B737 spoke to the Operations Manager; he said he knew he was cleared for [Runway] 34L and read it back; but the Copilot (flying the aircraft) had it in his mind he was landing Runway 34R and crossed over both finals of 34L and 34C; and lined up for 34R. The Captain said he told the Co-pilot he was lined up for the wrong runway and tried to adjust; but by that time trailing Air Carrier had closed the gap and was very close. The B737 didn't tell me; or the Tower about this maneuver; so no one knew what he was doing until he came on my frequency announcing his now deviation to the east. When the Captain of trailing Air Carrier called the TRACON he told the Operations Manager he was going to file a NMAC.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1075651
Time
Date	201303
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Q400
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	IFR
Person 1
Function	Approach Departure
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Conflict NMAC Deviation - Procedural Clearance Deviation - Track / Heading All Types

TRACON controller described a conflict event when traffic cleared for an approach to runway 34L but flew through the final for runway 34L and 34C resulting in a declared near midair collision. Pilot error was listed as the causal factor.