PLT OF A SMA INADVERTENTLY ENTERS CLASS B AIRSPACE WHILE FOCUSING ON TIS TFC DISPLAY.

Narrative

I WAS ALONE PRACTICING PRECISION MANEUVERS (STEEP TURNS; HOLDING ALT; ATC) IN AN AREA OF THE STL CLASS B THAT HAS A CEILING OF 4500 FT MSL. IT IS IN AN AREA THAT I CAN GET TIS TFC INFO ON MY MFD. STL APCH RECENTLY CHANGED SOME OF THEIR RADAR EQUIP AND SINCE THAT TIME; TIS HAS NOT WORKED WELL W OF THE LAMBERT (STL) FIELD. THE NOTCH I WAS FLYING IN IS AN EXCEPTION TO THAT WHERE I CAN RECEIVE ADVISORIES AND SINCE I WAS ALONE I WANTED TO HAVE THE TFC INFO. AT SOME POINT IN TIME DURING MY MANEUVERS; I NOTICED SOME TFC ON THE MFD ABOUT 5 NM N AT 4500 FT. I LOOKED TO FIND THE TFC AND WAS SURPRISED TO SEE A B737 CLBING OUT FROM LAMBERT -- SEEMED LOW. I LOOKED AGAIN AT MY MFD AND DISCOVERED THAT I HAD CROSSED OVER INTO THE 3000 FT RING OF CLASS B. I HAD STRAYED INTO THE WESTERN SECTION OF THE RING AT 3500 FT AND PERHAPS A MILE OR SO INTO IT. UPON RECOGNIZING THIS; I IMMEDIATELY INITIATED A DSCNT AND TOOK UP A WESTERN COURSE BACK TO THE 4500 FT AREA. THE AIRSPACE VIOLATION; I BELIEVE; WAS ONLY 2-3 MINS AT MOST IN DURATION. IT TOOK ME LESS THAN 30 SECONDS TO CLEAR THE AREA ONCE I RECOGNIZED THE PROB. IN RETROSPECT; I BELIEVE I JUST GOT TOO ABSORBED IN MY MANEUVERS AND IGNORED MY POSITION. IN THIS CASE THE TECHNOLOGY OF THE MFD AND TIS DREW ME INTO THIS AREA WITH A SENSE OF SAFETY. MY MFD DOES HAVE AIRSPACE ALARMS WHICH WOULD HAVE ALERTED ME TO THIS PROB BEFORE IT OCCURRED BUT I HAD TURNED OFF THE ALERTS. FLYING MUCH OF TIME AS I DO BENEATH AND CLOSE TO THE CLASS B; THE ALERTS GO OFF CONSTANTLY AND THUS BECOME A NUISANCE DURING 'REGULAR' FLYING.