Narrative:

We had been cleared for the ILS 28R at san francisco and had intercepted localizer and G/south. Descending through about 4000' on G/south, approach asked if we saw a government light transport at 12 O'clock at 1500'. We saw him as reported, he was east of brijj and southbound. We lost sight of him as he passed under th nose, we then entered a cloud layer approaching brijj outer marker at about 2000'. When we broke out below the cloud layer inside brijj at about 1600', the light transport was on our left wing at the same altitude and no more than 100 or 200' laterally, paralleling our course. We had switched to tower frequency at brijj, and tower asked if we still saw the government light transport. We continued down the G/south, and he maintained level flight, then made a right turn, passing over us by a few hundred feet. If the government light transport was under IFR control, he should not have been so close to us. If he was maneuvering VFR, he did not maintain VFR cloud clearance criteria. Neither approach control nor tower indicated that the government light transport would be turning toward the airport, or that he would follow the localizer, or that we should keep him in sight, and no followup position information was offered to us. Once he passed under our nose southbound we thought we were clear.

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Original NASA ASRS Text

Title: ACR LGT CLOSE ENCOUNTER WITH GOV LTT NEAR THE FINAL APCH FIX FOR RWY 28R AT SFO.

Narrative: WE HAD BEEN CLRED FOR THE ILS 28R AT SAN FRANCISCO AND HAD INTERCEPTED LOC AND G/S. DSNDING THROUGH ABOUT 4000' ON G/S, APCH ASKED IF WE SAW A GOV LTT AT 12 O'CLOCK AT 1500'. WE SAW HIM AS RPTED, HE WAS E OF BRIJJ AND SBND. WE LOST SIGHT OF HIM AS HE PASSED UNDER TH NOSE, WE THEN ENTERED A CLOUD LAYER APCHING BRIJJ OUTER MARKER AT ABOUT 2000'. WHEN WE BROKE OUT BELOW THE CLOUD LAYER INSIDE BRIJJ AT ABOUT 1600', THE LTT WAS ON OUR LEFT WING AT THE SAME ALT AND NO MORE THAN 100 OR 200' LATERALLY, PARALLELING OUR COURSE. WE HAD SWITCHED TO TWR FREQ AT BRIJJ, AND TWR ASKED IF WE STILL SAW THE GOV LTT. WE CONTINUED DOWN THE G/S, AND HE MAINTAINED LEVEL FLT, THEN MADE A RIGHT TURN, PASSING OVER US BY A FEW HUNDRED FEET. IF THE GOV LTT WAS UNDER IFR CONTROL, HE SHOULD NOT HAVE BEEN SO CLOSE TO US. IF HE WAS MANEUVERING VFR, HE DID NOT MAINTAIN VFR CLOUD CLRNC CRITERIA. NEITHER APCH CTL NOR TWR INDICATED THAT THE GOV LTT WOULD BE TURNING TOWARD THE ARPT, OR THAT HE WOULD FOLLOW THE LOC, OR THAT WE SHOULD KEEP HIM IN SIGHT, AND NO FOLLOWUP POS INFO WAS OFFERED TO US. ONCE HE PASSED UNDER OUR NOSE SBND WE THOUGHT WE WERE CLR.

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.