Narrative:

We were flight between dca-bdl, holding short of runway 18 dca for takeoff. Another air carrier flight was to land on runway 18 after a river visual approach. He erred and lined up for runway 15. Tower tried to subtly clue him in by asking him if he had runway 18 in sight when he was on final for runway 15. He said yes, but continued for runway 15. On short final, tower cleared him for landing on runway 18 or runway 15, his choice. This apparently got his attention and he said he would land on runway 18. The subsequent sidestep maneuver, in my opinion, put his aircraft dangerously close to ours. It crossed directly over ours at what I estimate at less than 100 ft. He then executed a missed approach. I recommend that tower not allow it to seem as though the sidestep is an option at such a low altitude. I doubt the other air carrier saw us.

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Original NASA ASRS Text

Title: AN ACR B737 FLC RPTS THAT ANOTHER ACR FLEW OVER THEIR ACFT WHILE ITS FLC WAS ATTEMPTING TO LINE UP WITH THE CORRECT RWY.

Narrative: WE WERE FLT BTWN DCA-BDL, HOLDING SHORT OF RWY 18 DCA FOR TKOF. ANOTHER ACR FLT WAS TO LAND ON RWY 18 AFTER A RIVER VISUAL APCH. HE ERRED AND LINED UP FOR RWY 15. TWR TRIED TO SUBTLY CLUE HIM IN BY ASKING HIM IF HE HAD RWY 18 IN SIGHT WHEN HE WAS ON FINAL FOR RWY 15. HE SAID YES, BUT CONTINUED FOR RWY 15. ON SHORT FINAL, TWR CLRED HIM FOR LNDG ON RWY 18 OR RWY 15, HIS CHOICE. THIS APPARENTLY GOT HIS ATTN AND HE SAID HE WOULD LAND ON RWY 18. THE SUBSEQUENT SIDESTEP MANEUVER, IN MY OPINION, PUT HIS ACFT DANGEROUSLY CLOSE TO OURS. IT CROSSED DIRECTLY OVER OURS AT WHAT I ESTIMATE AT LESS THAN 100 FT. HE THEN EXECUTED A MISSED APCH. I RECOMMEND THAT TWR NOT ALLOW IT TO SEEM AS THOUGH THE SIDESTEP IS AN OPTION AT SUCH A LOW ALT. I DOUBT THE OTHER ACR SAW US.

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.