Narrative:

Air carrier B on visual approach to runway 28R overshot his final and encroached on our final. Sfo approach was reporting 5 mi with fog, sky partially obscured. Flight visibility was at least 3 mi for entire approach. There was a thick haze layer about 1000' MSL, which made the approach difficult (or impossible) to see while outside the marker (bridge). However, the entire approach was conducted with at least VFR minimums. When air carrier B (arriving from the east) was cleared for the runway 28R visual, he apparently could not see the runway and overshot his turn on slightly. ATC pointed out the air carrier B traffic (and we acknowledged in sight) about 5 mi prior. ATC also instructed us to call when we had the san mateo bridge in sight. After we called the bridge in sight and air carrier B in sight, we were cleared for the runway 28L visual approach (even though we did not see the airport yet). We were arriving from the south. The hazard in this situation was the parallel visual approachs in marginal VFR WX. The 28L and 28R runways are very close together, and even with excellent WX, wing tip to wing tip approachs can be tense. We altered our course slightly to the right (.1 or .2 mile) to allow room for air carrier B. Since we had air carrier B in sight continually (ahead of us by about 1/2 or 1/4 mi), there was no conflict. But, the potential for conflict or collision was there. Recommendation: ensure all aircraft see appropriate traffic and the runway (not just airport) on these tight parallel approachs.

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Original NASA ASRS Text

Title: POTENTIAL CONFLICT WHEN APCH CTLR CLEARING ACFT FOR VISUAL APCH TO SFO BEFORE ACFT REPORT ARPT IN SIGHT. OPERATIONAL DEVIATION. TRACK DEVIATION.

Narrative: ACR B ON VISUAL APCH TO RWY 28R OVERSHOT HIS FINAL AND ENCROACHED ON OUR FINAL. SFO APCH WAS RPTING 5 MI WITH FOG, SKY PARTIALLY OBSCURED. FLT VIS WAS AT LEAST 3 MI FOR ENTIRE APCH. THERE WAS A THICK HAZE LAYER ABOUT 1000' MSL, WHICH MADE THE APCH DIFFICULT (OR IMPOSSIBLE) TO SEE WHILE OUTSIDE THE MARKER (BRIDGE). HOWEVER, THE ENTIRE APCH WAS CONDUCTED WITH AT LEAST VFR MINIMUMS. WHEN ACR B (ARRIVING FROM THE E) WAS CLRED FOR THE RWY 28R VISUAL, HE APPARENTLY COULD NOT SEE THE RWY AND OVERSHOT HIS TURN ON SLIGHTLY. ATC POINTED OUT THE ACR B TFC (AND WE ACKNOWLEDGED IN SIGHT) ABOUT 5 MI PRIOR. ATC ALSO INSTRUCTED US TO CALL WHEN WE HAD THE SAN MATEO BRIDGE IN SIGHT. AFTER WE CALLED THE BRIDGE IN SIGHT AND ACR B IN SIGHT, WE WERE CLRED FOR THE RWY 28L VISUAL APCH (EVEN THOUGH WE DID NOT SEE THE ARPT YET). WE WERE ARRIVING FROM THE S. THE HAZARD IN THIS SITUATION WAS THE PARALLEL VISUAL APCHS IN MARGINAL VFR WX. THE 28L AND 28R RWYS ARE VERY CLOSE TOGETHER, AND EVEN WITH EXCELLENT WX, WING TIP TO WING TIP APCHS CAN BE TENSE. WE ALTERED OUR COURSE SLIGHTLY TO THE RIGHT (.1 OR .2 MILE) TO ALLOW ROOM FOR ACR B. SINCE WE HAD ACR B IN SIGHT CONTINUALLY (AHEAD OF US BY ABOUT 1/2 OR 1/4 MI), THERE WAS NO CONFLICT. BUT, THE POTENTIAL FOR CONFLICT OR COLLISION WAS THERE. RECOMMENDATION: ENSURE ALL ACFT SEE APPROPRIATE TFC AND THE RWY (NOT JUST ARPT) ON THESE TIGHT PARALLEL APCHS.

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.