Pilot flying an small aircraft and descending to fly below the floor of class B does not descend rap...

Attributes
ACN	395760
Time
Date	199803
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sea
State Reference	WA
Altitude	msl bound lower : 7000 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sea
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 15 flight time total : 265 flight time type : 230
ASRS Report	395760
Events
Anomaly	non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : exited adverse environment
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Possible inadvertent incursion into sea class B airspace on the sea 135 degree radial at the 25 mi arc. (As shown on the sea VFR terminal area chart). I was descending from 8500 ft to 5500 ft, inbound on the sea 135 degree radial, with the intention to descend below the 6000 ft floor of the class B airspace prior to crossing the 25 mi arc. I might have gone into the class B airspace at about 7000 ft, executed a 180 degree turn to 135 degree (magnetic heading) and descended to 5500 ft before turning back to 315 degree magnetic heading and continuing northbound under the floor of the airspace. I was using pilotage and dead reckoning to establish my position relative to the 6000 ft floor of the class B airspace in that area. I believe tailwinds caused my ground speed to be faster than expected. Winds aloft forecast for 6000-9000 ft were about ssw at 10-13 KTS. So, I traveled northward quicker than expected while maintaining a 500 FPM descent rate. Flight conditions: high cirrus greater than 10000 ft MSL. Visibility approximately 60 NM. Slight haze. Occasional light turbulence in the vicinity of mount rainier. Winds aloft ssw 10-13 KTS forecast. Freezing level forecast 2000-4000 ft MSL.

Original NASA ASRS Text

Title: PLT FLYING AN SMA AND DSNDING TO FLY BELOW THE FLOOR OF CLASS B DOES NOT DSND RAPIDLY ENOUGH AND ENTERS THE CLASS B WITHOUT CLRNC.

Narrative: POSSIBLE INADVERTENT INCURSION INTO SEA CLASS B AIRSPACE ON THE SEA 135 DEG RADIAL AT THE 25 MI ARC. (AS SHOWN ON THE SEA VFR TERMINAL AREA CHART). I WAS DSNDING FROM 8500 FT TO 5500 FT, INBOUND ON THE SEA 135 DEG RADIAL, WITH THE INTENTION TO DSND BELOW THE 6000 FT FLOOR OF THE CLASS B AIRSPACE PRIOR TO XING THE 25 MI ARC. I MIGHT HAVE GONE INTO THE CLASS B AIRSPACE AT ABOUT 7000 FT, EXECUTED A 180 DEG TURN TO 135 DEG (MAGNETIC HDG) AND DSNDED TO 5500 FT BEFORE TURNING BACK TO 315 DEG MAGNETIC HDG AND CONTINUING NBOUND UNDER THE FLOOR OF THE AIRSPACE. I WAS USING PILOTAGE AND DEAD RECKONING TO ESTABLISH MY POS RELATIVE TO THE 6000 FT FLOOR OF THE CLASS B AIRSPACE IN THAT AREA. I BELIEVE TAILWINDS CAUSED MY GND SPD TO BE FASTER THAN EXPECTED. WINDS ALOFT FORECAST FOR 6000-9000 FT WERE ABOUT SSW AT 10-13 KTS. SO, I TRAVELED NORTHWARD QUICKER THAN EXPECTED WHILE MAINTAINING A 500 FPM DSCNT RATE. FLT CONDITIONS: HIGH CIRRUS GREATER THAN 10000 FT MSL. VISIBILITY APPROX 60 NM. SLIGHT HAZE. OCCASIONAL LIGHT TURB IN THE VICINITY OF MOUNT RAINIER. WINDS ALOFT SSW 10-13 KTS FORECAST. FREEZING LEVEL FORECAST 2000-4000 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.

Pilot flying an small aircraft and descending to fly below the floor of class B does not descend rapidly enough and enters the class B without clearance.