Narrative:

I was flying small aircraft X in support of radio. During the course of the flight I witnessed 2 flight violations. The first violation occurred west of chicago's loop area. While flying south along ogden ave from the lincoln park area at 1300' indicated, I saw a high wing small aircraft Y aircraft approach eastbound on the north side of the eisenhower expressway. I heard the small aircraft Y identify itself to meigs tower as xyz. The small aircraft Y continued east until over the intersection of the eisenhower and the day ryan expressway. The small aircraft Y then turned south on the east side of the dan ryan. Throughout this period the aircraft maintained the same altitude. I had just received an updated altimeter setting from miegs tower. The field elevation at meigs is 595'. The second violation occurred approximately XA35 on the same morning. While flying southbound along the tri state expressway on the east side between ogden avenue and the hinsdale oasis, I was passed on the left by a high wing small aircraft Y at the altitude, 1300' indicated. The small aircraft Y was within 100' of my aircraft when it passed. I watched the small aircraft Y continue towards midway air traffic area. I tuned my radio to midway tower frequency and heard the small aircraft Y identify itself as xyz. I continued to track the location of small aircraft Y until it was taxiing into parking area. At that time I flew near the aircraft on my approach to landing on the south ramp. It was a high wing small aircraft Y on the bottom with stripes and a dark top. I could not read the letters because they were so small.

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Original NASA ASRS Text

Title: NMAC BETWEEN 2 GA-SMA.

Narrative: I WAS FLYING SMA X IN SUPPORT OF RADIO. DURING THE COURSE OF THE FLT I WITNESSED 2 FLT VIOLATIONS. THE FIRST VIOLATION OCCURRED W OF CHICAGO'S LOOP AREA. WHILE FLYING S ALONG OGDEN AVE FROM THE LINCOLN PARK AREA AT 1300' INDICATED, I SAW A HIGH WING SMA Y ACFT APCH EBND ON THE N SIDE OF THE EISENHOWER EXPRESSWAY. I HEARD THE SMA Y IDENT ITSELF TO MEIGS TWR AS XYZ. THE SMA Y CONTINUED E UNTIL OVER THE INTXN OF THE EISENHOWER AND THE DAY RYAN EXPRESSWAY. THE SMA Y THEN TURNED S ON THE E SIDE OF THE DAN RYAN. THROUGHOUT THIS PERIOD THE ACFT MAINTAINED THE SAME ALT. I HAD JUST RECEIVED AN UPDATED ALTIMETER SETTING FROM MIEGS TWR. THE FIELD ELEVATION AT MEIGS IS 595'. THE SECOND VIOLATION OCCURRED APPROX XA35 ON THE SAME MORNING. WHILE FLYING SBND ALONG THE TRI STATE EXPRESSWAY ON THE E SIDE BTWN OGDEN AVENUE AND THE HINSDALE OASIS, I WAS PASSED ON THE LEFT BY A HIGH WING SMA Y AT THE ALT, 1300' INDICATED. THE SMA Y WAS WITHIN 100' OF MY ACFT WHEN IT PASSED. I WATCHED THE SMA Y CONTINUE TOWARDS MIDWAY ATA. I TUNED MY RADIO TO MIDWAY TWR FREQ AND HEARD THE SMA Y IDENT ITSELF AS XYZ. I CONTINUED TO TRACK THE LOCATION OF SMA Y UNTIL IT WAS TAXIING INTO PARKING AREA. AT THAT TIME I FLEW NEAR THE ACFT ON MY APCH TO LNDG ON THE S RAMP. IT WAS A HIGH WING SMA Y ON THE BOTTOM WITH STRIPES AND A DARK TOP. I COULD NOT READ THE LETTERS BECAUSE THEY WERE SO SMALL.

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.