C182RG pilot enters class B airspace without clearance. B747 is cut off on approach.

Attributes
ACN	333810
Time
Date	199604
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : iad
State Reference	VA
Altitude	msl bound lower : 2900 msl bound upper : 2900
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : iad
Operator	general aviation : personal
Make Model Name	Skylane 182/RG Turbo Skylane/RG
Operating Under FAR Part	Part 91
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	None
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B747 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 65 flight time total : 10000
ASRS Report	333810
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : far other anomaly other
Independent Detector	other controllera
Resolutory Action	flight crew : exited adverse environment other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While checking in with dulles approach to get class B clearance, dulles approach said aircraft was in class B at 2900 ft, 5 mi northeast of leesburg, va, and 'had just cut of a B747 landing at dulles.' I headed north out of class B and descended to go below class B. Controller came back and vectored me normally. I thought I was far enough northeast to be clear of class B at 3000 ft but guess I wasn't.

Original NASA ASRS Text

Title: C182RG PLT ENTERS CLASS B AIRSPACE WITHOUT CLRNC. B747 IS CUT OFF ON APCH.

Narrative: WHILE CHKING IN WITH DULLES APCH TO GET CLASS B CLRNC, DULLES APCH SAID ACFT WAS IN CLASS B AT 2900 FT, 5 MI NE OF LEESBURG, VA, AND 'HAD JUST CUT OF A B747 LNDG AT DULLES.' I HEADED N OUT OF CLASS B AND DSNDED TO GO BELOW CLASS B. CTLR CAME BACK AND VECTORED ME NORMALLY. I THOUGHT I WAS FAR ENOUGH NE TO BE CLR OF CLASS B AT 3000 FT BUT GUESS I WASN'T.

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.