Pilot of C172 improperly squawks VFR code within dc ADIZ after canceling flight plan with pct.

Attributes
ACN	601866
Time
Date	200312
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : jyo.airport
State Reference	VA
Altitude	msl single value : 1400
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	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private pilot : commercial
Experience	flight time last 90 days : 50 flight time total : 650 flight time type : 625
ASRS Report	601866
Person 2
Affiliation	government other
Function	other personnel other
Events
Anomaly	airspace violation : entry non adherence : published procedure non adherence : far
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Problem Areas	Flight Crew Human Performance Environmental Factor Airspace Structure Weather
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
Airspace Structure	special use : dcadiz.othersua

Narrative:

I was on the final leg of my IFR flight plan which originated in columbia, sc, that same morning with a stop in richmond, va. I was about 5 NM from my home base at jyo and, as required, I told the ATC controller that I 'had the airport in sight' and requested to have my IFR flight plan canceled. The controller told me this was done and gave me permission to 'change to the advisory frequency.' I also inadvertently interpreted this as permission to leave my assigned squawk code and change to the VFR squawk code 1200. During the approximately 5 mins from this time to landing, I proceeded directly to the leesburg airport and landed promptly, securing my aircraft due to the gusty conditions and ice and snow on the ramp. At the time of landing, I was given a message to call a phone number and was informed of the squawk code discrepancy. In retrospect, I think what happened was that during the very last few mins of a long and arduous day of solo flying the cumulative fatigue and stress of the effort caught up with me and I inadvertently went back in time to the old procedure I had been reconditioned to during the larger part of my trip, selecting the incorrect squawk code for a very brief period of time. It was an honest mistake I very much regret, but no one was hurt, no property was put in danger and I certainly have learned my lesson.

Original NASA ASRS Text

Title: PLT OF C172 IMPROPERLY SQUAWKS VFR CODE WITHIN DC ADIZ AFTER CANCELING FLT PLAN WITH PCT.

Narrative: I WAS ON THE FINAL LEG OF MY IFR FLT PLAN WHICH ORIGINATED IN COLUMBIA, SC, THAT SAME MORNING WITH A STOP IN RICHMOND, VA. I WAS ABOUT 5 NM FROM MY HOME BASE AT JYO AND, AS REQUIRED, I TOLD THE ATC CTLR THAT I 'HAD THE ARPT IN SIGHT' AND REQUESTED TO HAVE MY IFR FLT PLAN CANCELED. THE CTLR TOLD ME THIS WAS DONE AND GAVE ME PERMISSION TO 'CHANGE TO THE ADVISORY FREQ.' I ALSO INADVERTENTLY INTERPED THIS AS PERMISSION TO LEAVE MY ASSIGNED SQUAWK CODE AND CHANGE TO THE VFR SQUAWK CODE 1200. DURING THE APPROX 5 MINS FROM THIS TIME TO LNDG, I PROCEEDED DIRECTLY TO THE LEESBURG ARPT AND LANDED PROMPTLY, SECURING MY ACFT DUE TO THE GUSTY CONDITIONS AND ICE AND SNOW ON THE RAMP. AT THE TIME OF LNDG, I WAS GIVEN A MESSAGE TO CALL A PHONE NUMBER AND WAS INFORMED OF THE SQUAWK CODE DISCREPANCY. IN RETROSPECT, I THINK WHAT HAPPENED WAS THAT DURING THE VERY LAST FEW MINS OF A LONG AND ARDUOUS DAY OF SOLO FLYING THE CUMULATIVE FATIGUE AND STRESS OF THE EFFORT CAUGHT UP WITH ME AND I INADVERTENTLY WENT BACK IN TIME TO THE OLD PROC I HAD BEEN RECONDITIONED TO DURING THE LARGER PART OF MY TRIP, SELECTING THE INCORRECT SQUAWK CODE FOR A VERY BRIEF PERIOD OF TIME. IT WAS AN HONEST MISTAKE I VERY MUCH REGRET, BUT NO ONE WAS HURT, NO PROPERTY WAS PUT IN DANGER AND I CERTAINLY HAVE LEARNED MY LESSON.

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.