Narrative:

This was a short (10 mins), return flight to auburn, wa, (S50) from pierce county (IS0). The purpose of the flight to pierce was to warm the engine and refuel the plane with 80 octane. On departure at pierce, runway 34, I banked to the east until over the valley (the valley floor is 500 ft below pierce). Then I turned north and climbed to 1300 ft. This elevation is below the 1600 ft floor of seatac class B. After leveling off, I monitored flight watch xmissions on WX conditions to the north and south and also admired the scenery. I remember glancing at the altimeter and read it at 900 ft. I thought I had lost 400 ft. No problem, pattern ht at auburn is 1000 ft. On a 45 degree to enter the pattern for runway 16, I checked the altimeter and it read 1900 ft. Problem, had I violated the 1600 ft fan shaped floor of the class B? This is a stupid situation to be in. I got there by misreading the altimeter and by being complacent. The stair step shape of the class B in this area is asking for a violation if you don't pay close attention. Transient VFR pilots flying to the north or to the south are likely to violate this small section of the fan shaped class B airspace. Seatac and federal way are on a long peninsula, 500 ft higher than the valley. The separation between the 2 is abrupt, a cliff. The highway follows the valley floor next to the cliff. VFR pilots navigation over landmarks. Hwys are great landmarks. It would be nice if the FAA could give up a small piece of this class B fan, changing the boundary to run along highway 167. The highway follows the valley floor next to the cliff. This would raise the ceiling to 3000 ft, that of the surrounding airspace to the east.

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Original NASA ASRS Text

Title: PVT PLT OF AN SMA SEL INADVERTENTLY ENTERED CLASS B AIRSPACE WHILE ENRTE TO AN UNDERLYING ARPT.

Narrative: THIS WAS A SHORT (10 MINS), RETURN FLT TO AUBURN, WA, (S50) FROM PIERCE COUNTY (IS0). THE PURPOSE OF THE FLT TO PIERCE WAS TO WARM THE ENG AND REFUEL THE PLANE WITH 80 OCTANE. ON DEP AT PIERCE, RWY 34, I BANKED TO THE E UNTIL OVER THE VALLEY (THE VALLEY FLOOR IS 500 FT BELOW PIERCE). THEN I TURNED N AND CLBED TO 1300 FT. THIS ELEVATION IS BELOW THE 1600 FT FLOOR OF SEATAC CLASS B. AFTER LEVELING OFF, I MONITORED FLT WATCH XMISSIONS ON WX CONDITIONS TO THE N AND S AND ALSO ADMIRED THE SCENERY. I REMEMBER GLANCING AT THE ALTIMETER AND READ IT AT 900 FT. I THOUGHT I HAD LOST 400 FT. NO PROB, PATTERN HT AT AUBURN IS 1000 FT. ON A 45 DEG TO ENTER THE PATTERN FOR RWY 16, I CHKED THE ALTIMETER AND IT READ 1900 FT. PROB, HAD I VIOLATED THE 1600 FT FAN SHAPED FLOOR OF THE CLASS B? THIS IS A STUPID SIT TO BE IN. I GOT THERE BY MISREADING THE ALTIMETER AND BY BEING COMPLACENT. THE STAIR STEP SHAPE OF THE CLASS B IN THIS AREA IS ASKING FOR A VIOLATION IF YOU DON'T PAY CLOSE ATTN. TRANSIENT VFR PLTS FLYING TO THE N OR TO THE S ARE LIKELY TO VIOLATE THIS SMALL SECTION OF THE FAN SHAPED CLASS B AIRSPACE. SEATAC AND FEDERAL WAY ARE ON A LONG PENINSULA, 500 FT HIGHER THAN THE VALLEY. THE SEPARATION BTWN THE 2 IS ABRUPT, A CLIFF. THE HWY FOLLOWS THE VALLEY FLOOR NEXT TO THE CLIFF. VFR PLTS NAV OVER LANDMARKS. HWYS ARE GREAT LANDMARKS. IT WOULD BE NICE IF THE FAA COULD GIVE UP A SMALL PIECE OF THIS CLASS B FAN, CHANGING THE BOUNDARY TO RUN ALONG HWY 167. THE HWY FOLLOWS THE VALLEY FLOOR NEXT TO THE CLIFF. THIS WOULD RAISE THE CEILING TO 3000 FT, THAT OF THE SURROUNDING AIRSPACE TO THE E.

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.