C172 entered washington ADIZ without clearance.

Attributes
ACN	598644
Time
Date	200311
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : aml.vortac
State Reference	VA
Altitude	msl single value : 4500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pct.tracon
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	VFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time total : 210
ASRS Report	598644
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	airspace violation : entry non adherence : clearance non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance Airspace Structure
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was flying close to the washington, dc, ADIZ and was calling for a transponder code. I received a transponder code but was not given permission to enter the ADIZ. I was 1/2 NM from the boundary when I asked potomac approach for permission to enter the ADIZ. I was told 'negative, I do not have radar contact, identify.' at this point, the GPS still indicating that I was outside of class B airspace. My altimeter showed that I was at 4450 ft. The controller told me that he had a radar contact (after identify), but I had violated class B airspace. He chewed me out and told me to maintain 4500 ft. I chose not to argue with him and acknowledged receipt of transmission that I had violated airspace. 10 mins later, I heard this controller give somebody else altimeter setting. It was significantly different from my setting. I had listened to jyo AWOS and my settings were consistent with the AWOS. When I landed at jyo, my altimeter reported the altitude of the airport with less than 10 ft error. Contributing factors: I was too close to the class B boundary. I do not believe I violated the airspace. In addition, the potomac approach controller was giving out incorrect altimeter settings, but failed to give me altimeter settings when I first contacted him. This probably led him to believe I was at a higher altitude. This controller was also extremely busy.

Original NASA ASRS Text

Title: C172 ENTERED WASHINGTON ADIZ WITHOUT CLRNC.

Narrative: I WAS FLYING CLOSE TO THE WASHINGTON, DC, ADIZ AND WAS CALLING FOR A XPONDER CODE. I RECEIVED A XPONDER CODE BUT WAS NOT GIVEN PERMISSION TO ENTER THE ADIZ. I WAS 1/2 NM FROM THE BOUNDARY WHEN I ASKED POTOMAC APCH FOR PERMISSION TO ENTER THE ADIZ. I WAS TOLD 'NEGATIVE, I DO NOT HAVE RADAR CONTACT, IDENT.' AT THIS POINT, THE GPS STILL INDICATING THAT I WAS OUTSIDE OF CLASS B AIRSPACE. MY ALTIMETER SHOWED THAT I WAS AT 4450 FT. THE CTLR TOLD ME THAT HE HAD A RADAR CONTACT (AFTER IDENT), BUT I HAD VIOLATED CLASS B AIRSPACE. HE CHEWED ME OUT AND TOLD ME TO MAINTAIN 4500 FT. I CHOSE NOT TO ARGUE WITH HIM AND ACKNOWLEDGED RECEIPT OF XMISSION THAT I HAD VIOLATED AIRSPACE. 10 MINS LATER, I HEARD THIS CTLR GIVE SOMEBODY ELSE ALTIMETER SETTING. IT WAS SIGNIFICANTLY DIFFERENT FROM MY SETTING. I HAD LISTENED TO JYO AWOS AND MY SETTINGS WERE CONSISTENT WITH THE AWOS. WHEN I LANDED AT JYO, MY ALTIMETER RPTED THE ALT OF THE ARPT WITH LESS THAN 10 FT ERROR. CONTRIBUTING FACTORS: I WAS TOO CLOSE TO THE CLASS B BOUNDARY. I DO NOT BELIEVE I VIOLATED THE AIRSPACE. IN ADDITION, THE POTOMAC APCH CTLR WAS GIVING OUT INCORRECT ALTIMETER SETTINGS, BUT FAILED TO GIVE ME ALTIMETER SETTINGS WHEN I FIRST CONTACTED HIM. THIS PROBABLY LED HIM TO BELIEVE I WAS AT A HIGHER ALT. THIS CTLR WAS ALSO EXTREMELY BUSY.

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.