C182 pilot reported inadvertent entry into sfo class B airspace.

Attributes
ACN	1445517
Time
Date	201705
Local Time Of Day	1201-1800
Place
Locale Reference	SJC.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skylane 182/RG Turbo Skylane/RG
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	None
Flight Plan	None
Person 1
Function	Pilot Flying Single Pilot
Experience	Flight Crew Last 90 Days 3 Flight Crew Total 287 Flight Crew Type 287
Events
Anomaly	Airspace Violation All Types Deviation - Procedural FAR

Narrative:

Flying VFR from the coastline toward sjc airspace. I was below the sfo class B shelf when I began checking the destination weather. I drifted up to the bottom of the class B shelf. The altitude gain appears to have been caused by ridge lift. I do not believe that I entered class B; but it is possible; depending on what altimeter setting the radar facility was using. As soon as I noticed I was near the shelf altitude; I descended well clear. I should have been more aware of the possibility of ridge lift and maintained a larger altitude margin to the class B shelf. I also could have moved my route 3 miles west; where the shelf is 2;000 feet higher; to allow a larger altitude margin to the class B shelf while maintaining clearance above the ridge.

Original NASA ASRS Text

Title: C182 pilot reported inadvertent entry into SFO Class B airspace.

Narrative: Flying VFR from the coastline toward SJC airspace. I was below the SFO class B shelf when I began checking the destination weather. I drifted up to the bottom of the class B shelf. The altitude gain appears to have been caused by ridge lift. I do not believe that I entered class B; but it is possible; depending on what altimeter setting the radar facility was using. As soon as I noticed I was near the shelf altitude; I descended well clear. I should have been more aware of the possibility of ridge lift and maintained a larger altitude margin to the class B shelf. I also could have moved my route 3 miles West; where the shelf is 2;000 feet higher; to allow a larger altitude margin to the class B shelf while maintaining clearance above the ridge.

Data retrieved from NASA's ASRS site 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.