PIPELINE INSPECTION ACFT ENTERS CLASS C AIRSPACE WITHOUT CLRNC.

Narrative

PLT WAS FLYING WKLY PETROLEUM (UNDERGND) PIPELINE RTE WHICH TRAVERSES INTO WRIGHT-PATTERSON AFB CLASS D AIRSPACE; INCLUDING A PIPELINE CARRYING JET FUEL TO TANKAGE ON THE BASE. PLT CONTACTED WRIGHT-PATTERSON AFB TWR ABOUT 14 MI NE ON 126.9 AND WAS TOLD TO CONTACT TWR AGAIN WHEN ACTUALLY ENTERING CLASS D. I CONTACTED TWR AT 6.2 MI OUT AND WAS TOLD (FOR THE FIRST TIME IN 1 1/2 YRS OF FLYING THIS RTE) THAT ENTRANCE WAS DENIED DUE TO SPECIAL EXERCISES ON THE BASE. I DECIDED TO CIRCUMNAV CLASS D COUNTERCLOCKWISE TO RESUME THE PIPELINE RTE ON THE SW SIDE OF WRIGHT-PATTERSON AFB. I SET THE GPS TO FFO AND MAINTAINED 5 PLUS NM DISTANCE FROM WRIGHT-PATTERSON AFB AS I FLEW AROUND. AS I WAS FLYING ON THE NW SIDE OF WRIGHT-PATTERSON AFB I NOTICED MGY ABOUT EQUIDISTANT OFF MY R WING (WITH WRIGHT-PATTERSON AFB OFF MY L WING). I GOT AS CLOSED AS 4.6 NM TO FFO. I DO NOT KNOW MY DISTANCE FROM MGY. WHEN I LATER LANDED I REVIEWED THE SECTIONAL MAP AND NOTICEABLE THE WRIGHT-PATTERN AFB CLASS D AND DAY CLASS C INNER RINGS APPEAR TO JUST TOUCH; HENCE I MAY HAVE ENTERED (BARELY) ONE OR THE OTHER. COMPLICATING THIS IS WHILE UP-TO-DATE SECTIONALS WERE ON BOARD; PIPELINE PLTS NORMALLY USE SPECIALIZED STRIP MAPS SHOWING ONLY ABOUT 1 MI ON EACH SIDE OF PIPELINE. WITH HINDSIGHT I SHOULD HAVE CALLED DAY APCH.