A BEECH BONANZA PLT ENTERED D01 CLASS B AIRSPACE WITHOUT CLRNC DUE TO AN ALTIMETER FAILURE.

Narrative

I WAS FLYING BONANZA; IFR EQUIPPED; BUT UNDER VFR ON A XCOUNTRY FLT; WITHOUT A FLT PLAN; FROM APA TO 1V5. MY INTENTION WAS TO USE A RTE BENEATH THE DEN CLASS B AIRSPACE ACCORDING TO THE APPROVED AND CURRENT SECTIONAL CHART. THE RTE WAS TO BE AT A SEGMENT ON THE W SIDE OF THE CLASS B AND AT 7500 FT MSL. THE FLOOR IN THE AREA IS 8000 FT MSL. I DEPARTED BOULDER INTENDING TO RETURN BY THE SAME RTE AS EARLIER. SENSING THAT DEN. APCH WAS BUSY I DID NOT CALL FOR FLT FOLLOWING. I SET MY ALTIMETER TO THE BOULDER FIELD ELEVATION AND NOTICED NO PROBS WITH EITHER THE SETTING KNOB OR THE ALTIMETER ITSELF. INFLT ON THE RETURN; I HAD AN UPDATE FROM APA ATIS. WHEN RESETTING THE ALTIMETER I NOTICED THAT THE KOHLSMAN KNOB WAS EXTREMELY STIFF AND BECAME COMPLETELY BOUND UP. I DISCONTINUED TRYING TO SET IT IN FAVOR OF FLYING THE ACFT. ON FINAL AT APA ABOUT XA45 MDT I WAS REQUESTED BY APA TWR TO CALL APCH BY TELEPHONE. I DID AND EXPLAINED THE MALFUNCTION. AT NO TIME DID ANY INSTS INDICATE I WAS IN THE CLASS B AIRSPACE; NOT DID I BELIEVE I WAS IN THE CLASS B AIRSPACE. MY XPONDER WAS ALSO ON AND FUNCTIONING ON BOTH FLTS. SINCE THIS EVENT I HAD THE ALTIMETER CHKED AND REPLACED. THIS WAS THE FIRST INDICATION OF ANY PROB AND AFTER DISCOVERY I LANDED IMMEDIATELY AND DID NOT FLY AGAIN UNTIL IT WAS REPAIRED.