INADVERTENT ENTRY INTO CLASS B AIRSPACE.

Narrative

THIS WAS MY FIRST TRIP TO BKL AND INTO CLASS B AIRSPACE; AND BECAUSE OF CONCERNS ABOUT NAVIGATING CLASS B AIRSPACE;I HIRED A CFI TO ACCOMPANY ME. FLT TO BKL WAS UNEVENTFUL. CFI AND I PLANNED DEP FROM BKL AND DECIDED TO TURN TO HDG OF 180 DEGS (COMPARED TO DESIRED HDG OF 210 DEGS) AND LEVEL OFF AT 3000 FT MSL (AS COMPARED TO DESIRED ALT OF 4500 FT MSL) UNTIL CLRED INTO CLASS B AIRSPACE. FOLLOWING CLRNC INTO CLASS B AIRSPACE AND BEING ASSIGNED HDG AND ALT; CLEVELAND APCH CTLR SAID WE HAD ENTERED CLASS B AIRSPACE BEFORE CLRNC; AND WERE 9 MI FROM FIELD (HOPKINS). HE DID NOT INDICATE AN ALT. AT 9 MI FROM THE FIELD; WE WERE IN AN AREA WHERE THE FLOOR OF THE AIRSPACE WAS 3000 FT MSL. THE BAROMETER HAD BEEN SET PRIOR TO TKOF AND I WAS CAREFUL NOT TO EXCEED 3000 FT; BUT IT IS POSSIBLE THAT THERE WAS A MOMENTARY INCURSION BY A SMALL AMOUNT. I GUESS IT IS ALSO POSSIBLE THAT ALTIMETER OR XPONDER WERE IN ERROR. IN THE FUTURE I WILL FLY A LOWER ALT UNTIL CLRED TO LEAVE A MARGIN FOR ERROR; BUT TALL TWRS IN THE AREA DO NOT LEAVE MUCH ROOM. PERHAPS THE BEST APCH IS TO FLY A HDG OF 140 DEGS TO AVOID TWRS AND STAY AT 2500 FT MSL.