A mooney 20K private pilot flies into the floor of the class B airspace of sfo near osi, ca.

Attributes
ACN	534781
Time
Date	200112
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : osi.vortac
State Reference	CA
Altitude	msl bound lower : 4000 msl bound upper : 4500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : o90.tracon
Operator	general aviation : personal
Make Model Name	M-20 K (231)
Operating Under FAR Part	Part 91
Navigation In Use	other vortac
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 60 flight time total : 480 flight time type : 110
ASRS Report	534781
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	airspace violation : entry non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : exited penetrated airspace none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance Chart Or Publication Airspace Structure
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Inadvertent violation of class B airspace vertical limits. Thought class B floor was at 6000 ft, as I was climbing up to/through 4500 ft (actual floor was still 4000 ft MSL).

Original NASA ASRS Text

Title: A MOONEY 20K PVT PLT FLIES INTO THE FLOOR OF THE CLASS B AIRSPACE OF SFO NEAR OSI, CA.

Narrative: INADVERTENT VIOLATION OF CLASS B AIRSPACE VERT LIMITS. THOUGHT CLASS B FLOOR WAS AT 6000 FT, AS I WAS CLBING UP TO/THROUGH 4500 FT (ACTUAL FLOOR WAS STILL 4000 FT MSL).

Data retrieved from NASA's ASRS site as of July 2007 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.