Narrative:

C172 on flight from leb to 9b1 direct (pilotage, dr, LORAN, and portable GPS, course 170 degrees magnetic), contacted ZBW upon departure and established with them a squawk (mode C garmin 330) code, altimeter setting, route (leb-9b1 direct), en route altitude (7500 ft), aircraft type and RA's request. ZBW reported radar contact. Approximately 35 NM from mht boston handed me off to manchester approach. Pilot completed radio contact with manchester approach, and received an updated current altimeter. At approximately 270 degree radial 18 NM from mht pilot heard air carrier cleared (from 9000 ft?) to 5000 ft. Approach contacted me by call sign and advised of traffic at 2 O'clock position descending to 5000 ft with mention of 'passing below you.' both aircraft reported traffic in sight. Approach requested me to take responsibility for visual separation, I accepted responsibility. Approach informed air carrier I was accepting responsibility for visual separation. Without further communication between either pilot and approach, I climbed 200 ft and 7700 ft before air carrier passed beneath and immediately reported passing 7000 ft to approach. Soon after, air carrier contacted approach to determine identify of passing aircraft. FBO at 9b1 received and passed on to me instruction to contact the supervisor at manchester approach. I placed that call immediately, and conversation with the supervisor included disclosure that air carrier had TCASII monitoring the situation, that manchester ATC radar had been unable to resolve the 2 aircraft (a radar shadowing problem?), and pilot acknowledged he was clear about accepting visual separation responsibility and felt that separation had been maintained.

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Original NASA ASRS Text

Title: C172 PLT WAS TOLD BY ZBW TO MAINTAIN VISUAL SEPARATION FROM A B737 WHICH RESULTED IN A CONFLICT.

Narrative: C172 ON FLT FROM LEB TO 9B1 DIRECT (PILOTAGE, DR, LORAN, AND PORTABLE GPS, COURSE 170 DEGS MAGNETIC), CONTACTED ZBW UPON DEP AND ESTABLISHED WITH THEM A SQUAWK (MODE C GARMIN 330) CODE, ALTIMETER SETTING, RTE (LEB-9B1 DIRECT), ENRTE ALT (7500 FT), ACFT TYPE AND RA'S REQUEST. ZBW RPTED RADAR CONTACT. APPROX 35 NM FROM MHT BOSTON HANDED ME OFF TO MANCHESTER APCH. PLT COMPLETED RADIO CONTACT WITH MANCHESTER APCH, AND RECEIVED AN UPDATED CURRENT ALTIMETER. AT APPROX 270 DEG RADIAL 18 NM FROM MHT PLT HEARD ACR CLRED (FROM 9000 FT?) TO 5000 FT. APCH CONTACTED ME BY CALL SIGN AND ADVISED OF TFC AT 2 O'CLOCK POS DSNDING TO 5000 FT WITH MENTION OF 'PASSING BELOW YOU.' BOTH ACFT RPTED TFC IN SIGHT. APCH REQUESTED ME TO TAKE RESPONSIBILITY FOR VISUAL SEPARATION, I ACCEPTED RESPONSIBILITY. APCH INFORMED ACR I WAS ACCEPTING RESPONSIBILITY FOR VISUAL SEPARATION. WITHOUT FURTHER COM BTWN EITHER PLT AND APCH, I CLBED 200 FT AND 7700 FT BEFORE ACR PASSED BENEATH AND IMMEDIATELY RPTED PASSING 7000 FT TO APCH. SOON AFTER, ACR CONTACTED APCH TO DETERMINE IDENT OF PASSING ACFT. FBO AT 9B1 RECEIVED AND PASSED ON TO ME INSTRUCTION TO CONTACT THE SUPVR AT MANCHESTER APCH. I PLACED THAT CALL IMMEDIATELY, AND CONVERSATION WITH THE SUPVR INCLUDED DISCLOSURE THAT ACR HAD TCASII MONITORING THE SIT, THAT MANCHESTER ATC RADAR HAD BEEN UNABLE TO RESOLVE THE 2 ACFT (A RADAR SHADOWING PROB?), AND PLT ACKNOWLEDGED HE WAS CLR ABOUT ACCEPTING VISUAL SEPARATION RESPONSIBILITY AND FELT THAT SEPARATION HAD BEEN MAINTAINED.

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.