Narrative:

Small aircraft X while on pleasure flight returning from GGG to 2m19 a decision was made to give a tour of downtown detroit by circumnav below floor of TCA. Dtw was called for VFR advisories 12 DME northwest of svm and advised of plan. Turning wbound southeast of TCA over grosse isle and proceeding direct crl VOR at 2300 ft, dtw controller advised a new heading to maintain 11 mi from dtw departure corridor. I descended to 2000 to help controller. Handoff to west sector controller went smoothly. I advised controller we were approaching arb air traffic area suggested frequency change. Dtw told me to remain with him that he would advise arb tower I was there. Later called traffic, an small aircraft Y, eastbound 10 O'clock, 2 mi 'has you in sight.' my heading was 350 degrees. Small aircraft Y was approximately 90 degrees. Small aircraft Y continued on intercept course, forcing me to deviate sharply left to avoid collision. Pilot of small aircraft Y had me in sight and I was to his right. Small aircraft Y never altered course. Shortly after this, a second small aircraft on largely same situation forced a second deviation. This time separation was greater, but he deviated left, forcing me to take evasive action left. Dtw should have accepted my request to switch to arb tower. This would have prevented direct communication with controling agency and would have perhaps given me a clue what small aircraft pilots were thinking.

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Original NASA ASRS Text

Title: SMA X HAD NMAC WITH SMA Y IN ARB ATA. EVASIVE ACTION TAKEN BY SMA X. SEE AND AVOID CONCEPT.

Narrative: SMA X WHILE ON PLEASURE FLT RETURNING FROM GGG TO 2M19 A DECISION WAS MADE TO GIVE A TOUR OF DOWNTOWN DETROIT BY CIRCUMNAV BELOW FLOOR OF TCA. DTW WAS CALLED FOR VFR ADVISORIES 12 DME NW OF SVM AND ADVISED OF PLAN. TURNING WBOUND SE OF TCA OVER GROSSE ISLE AND PROCEEDING DIRECT CRL VOR AT 2300 FT, DTW CTLR ADVISED A NEW HDG TO MAINTAIN 11 MI FROM DTW DEP CORRIDOR. I DSNDED TO 2000 TO HELP CTLR. HDOF TO W SECTOR CTLR WENT SMOOTHLY. I ADVISED CTLR WE WERE APCHING ARB ATA SUGGESTED FREQ CHANGE. DTW TOLD ME TO REMAIN WITH HIM THAT HE WOULD ADVISE ARB TWR I WAS THERE. LATER CALLED TFC, AN SMA Y, EBOUND 10 O'CLOCK, 2 MI 'HAS YOU IN SIGHT.' MY HDG WAS 350 DEGS. SMA Y WAS APPROX 90 DEGS. SMA Y CONTINUED ON INTERCEPT COURSE, FORCING ME TO DEVIATE SHARPLY L TO AVOID COLLISION. PLT OF SMA Y HAD ME IN SIGHT AND I WAS TO HIS R. SMA Y NEVER ALTERED COURSE. SHORTLY AFTER THIS, A SECOND SMA ON LARGELY SAME SITUATION FORCED A SECOND DEV. THIS TIME SEPARATION WAS GREATER, BUT HE DEVIATED L, FORCING ME TO TAKE EVASIVE ACTION L. DTW SHOULD HAVE ACCEPTED MY REQUEST TO SWITCH TO ARB TWR. THIS WOULD HAVE PREVENTED DIRECT COM WITH CTLING AGENCY AND WOULD HAVE PERHAPS GIVEN ME A CLUE WHAT SMA PLTS WERE THINKING.

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.