During an atx training flight, class B airspace was inadvertently penetrated.

Attributes
ACN	319880
Time
Date	199511
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : hwd
State Reference	CA
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	Marginal
Light	Night
Aircraft 1
Controlling Facilities	tracon : oak
Operator	common carrier : air taxi
Make Model Name	Golden Eagle 421
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Flight Plan	None
Person 1
Affiliation	company : air taxi
Function	flight crew : captain observation : company check pilot oversight : pic
Qualification	other other : other pilot : atp pilot : cfi
Experience	flight time last 90 days : 50 flight time total : 4000 flight time type : 400
ASRS Report	319880
Person 2
Affiliation	company : air taxi
Function	flight crew : first officer instruction : trainee
Qualification	other other : other pilot : commercial pilot : instrument
Events
Anomaly	inflight encounter : weather non adherence : far other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Having departed hwd in marginal VFR to avoid lengthy IFR delays, I accepted a vector (130) from ATC to avoid inbound traffic to oak. Visibility got lower, and I requested and received concurrence from ATC to climb unrestricted. Doing so, I clipped the bottom of the B airspace. Factors: critiquing my student and scanning for traffic to the exclusion of positive position awareness. Contributing: my assumption that ATC would not have given me an unrestricted climb below B airspace. You know what they say about he who assumes!

Original NASA ASRS Text

Title: DURING AN ATX TRAINING FLT, CLASS B AIRSPACE WAS INADVERTENTLY PENETRATED.

Narrative: HAVING DEPARTED HWD IN MARGINAL VFR TO AVOID LENGTHY IFR DELAYS, I ACCEPTED A VECTOR (130) FROM ATC TO AVOID INBOUND TFC TO OAK. VISIBILITY GOT LOWER, AND I REQUESTED AND RECEIVED CONCURRENCE FROM ATC TO CLB UNRESTRICTED. DOING SO, I CLIPPED THE BOTTOM OF THE B AIRSPACE. FACTORS: CRITIQUING MY STUDENT AND SCANNING FOR TFC TO THE EXCLUSION OF POSITIVE POS AWARENESS. CONTRIBUTING: MY ASSUMPTION THAT ATC WOULD NOT HAVE GIVEN ME AN UNRESTRICTED CLB BELOW B AIRSPACE. YOU KNOW WHAT THEY SAY ABOUT HE WHO ASSUMES!

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.