Possible airspace violation due to lowering clouds and rain.

Attributes
ACN	301171
Time
Date	199504
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pao airport : sql
State Reference	CA
Altitude	msl bound lower : 2400 msl bound upper : 2400
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sjc
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other cruise other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 5 flight time total : 140 flight time type : 80
ASRS Report	301171
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	inflight encounter : weather non adherence : far other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : exited adverse environment
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation

Narrative:

Flight from mry to sql. Intended to fly moss landing direct osi, then to sql. Approaching santa cruz, realized the ceiling was low over the hills. Attempted to go up the valley and stay below the ceiling. Realized I was below the ridge line on my left and the ceiling was not rising. Opted to cross the hills to the sjc side. Considerations: worried about being on lee side of the hills with a cross-ridge wind, avoid sjc class C. Got to sjc side, flying north. Ceiling dropped to 0 dead ahead. To avoid clouds needed to turn toward sjc. I was between 2400 ft and 2500 ft MSL at the time. I called bay approach for permission to enter the class C to avoid the cloud. Radar contact at (about) 7 mi from sjc. Problem: I may have clipped the 2500 ft floor of the class C before I received radio acknowledgement. Lessons: 1) CFIT and 'the box canyon mistake' can sneak up anytime the ceiling is low. 2) calling ATC early is always better than calling them late. 3) a forecast of 3000-5000 ft broken over hills with a safe altitude of 3900 ft should always get attention, even if the current report is 3000-5000 ft scattered and improving. 4) the sf bay airspace is complex, the pilot load for just getting around is high. In a stress situation it's not easy. Upon further consideration and reference to the sf terminal area chart, I feel sure I violated moffet's class D while circling over I-280 waiting for the rain to dissipate and getting set up to call pao for permission to transition.

Original NASA ASRS Text

Title: POSSIBLE AIRSPACE VIOLATION DUE TO LOWERING CLOUDS AND RAIN.

Narrative: FLT FROM MRY TO SQL. INTENDED TO FLY MOSS LNDG DIRECT OSI, THEN TO SQL. APCHING SANTA CRUZ, REALIZED THE CEILING WAS LOW OVER THE HILLS. ATTEMPTED TO GO UP THE VALLEY AND STAY BELOW THE CEILING. REALIZED I WAS BELOW THE RIDGE LINE ON MY L AND THE CEILING WAS NOT RISING. OPTED TO CROSS THE HILLS TO THE SJC SIDE. CONSIDERATIONS: WORRIED ABOUT BEING ON LEE SIDE OF THE HILLS WITH A CROSS-RIDGE WIND, AVOID SJC CLASS C. GOT TO SJC SIDE, FLYING N. CEILING DROPPED TO 0 DEAD AHEAD. TO AVOID CLOUDS NEEDED TO TURN TOWARD SJC. I WAS BTWN 2400 FT AND 2500 FT MSL AT THE TIME. I CALLED BAY APCH FOR PERMISSION TO ENTER THE CLASS C TO AVOID THE CLOUD. RADAR CONTACT AT (ABOUT) 7 MI FROM SJC. PROB: I MAY HAVE CLIPPED THE 2500 FT FLOOR OF THE CLASS C BEFORE I RECEIVED RADIO ACKNOWLEDGEMENT. LESSONS: 1) CFIT AND 'THE BOX CANYON MISTAKE' CAN SNEAK UP ANYTIME THE CEILING IS LOW. 2) CALLING ATC EARLY IS ALWAYS BETTER THAN CALLING THEM LATE. 3) A FORECAST OF 3000-5000 FT BROKEN OVER HILLS WITH A SAFE ALT OF 3900 FT SHOULD ALWAYS GET ATTN, EVEN IF THE CURRENT RPT IS 3000-5000 FT SCATTERED AND IMPROVING. 4) THE SF BAY AIRSPACE IS COMPLEX, THE PLT LOAD FOR JUST GETTING AROUND IS HIGH. IN A STRESS SIT IT'S NOT EASY. UPON FURTHER CONSIDERATION AND REF TO THE SF TERMINAL AREA CHART, I FEEL SURE I VIOLATED MOFFET'S CLASS D WHILE CIRCLING OVER I-280 WAITING FOR THE RAIN TO DISSIPATE AND GETTING SET UP TO CALL PAO FOR PERMISSION TO TRANSITION.

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.