SINGLE PLT OF PA46 FAILS TO SQUAWK DISCRETE XPONDER CODE ON DEP FROM GAI IN THE DC ADIZ.

Narrative

I TOOK OFF ON AN IFR FLT FROM GAITHERSBURG; MD; TO GARY; IN; WHILE INADVERTENTLY SQUAWKING THE VFR XPONDER CODE INSTEAD OF THE ASSIGNED CODE. THE POTOMAC DEP CTLR AND I BOTH DETECTED THE ERROR IMMEDIATELY AND VIRTUALLY SIMULTANEOUSLY. I SQUAWKED THE WRONG CODE FOR LESS THAN 2 MINS AND NEITHER PERSONS NOR PROPERTY WERE EVER IN DANGER. POTOMAC CLRNC DELIVERY CLRED ME AND RELEASED ME ON AN IFR FLT PLAN FROM GAI TO GYY. I TOOK OFF; FLEW THE ASSIGNED VECTOR; AND WAS CLBING TO THE ASSIGNED ALT OF 3000 FT MSL. AT 1500-2000 FT MSL; WHILE SWITCHING THE RADIO FROM THE GAI CTAF FREQ TO POTOMAC APCH CTL FREQ; I NOTICED THAT I HAD INADVERTENTLY NOT ENTERED THE ASSIGNED XPONDER CODE -- IT WAS SET TO 1200. I WAS SWITCHING THE XPONDER CODE AS I MADE INITIAL CONTACT WITH POTOMAC APCH. I ANNOUNCED TO THE CTLR THAT I WAS OFF GAI AND CLBING. THE CTLR ACKNOWLEDGED MY XMISSION AND SAID; 'SQUAWK XXXX.' I UTTERED LIKE; 'OH; NO!' I ACKNOWLEDGED THE INSTRUCTION AND FINISHED ENTERING THE CORRECT XPONDER CODE AND THE CTLR STATED; 'RADAR CONTACT' AND ISSUED VECTOR INSTRUCTIONS FOR CLBING. THE PRINCIPAL CAUSE OF THIS INCIDENT WAS SELF-INDUCED STRESS. MY WIFE WAS FRIGHTENED AND SHE EXPRESSED CONCERN ABOUT MY PLANNED DEP ON THE NEXT MORNING. THAT MORNING I LEFT ALONE EARLY FOR A ROUND-TRIP FROM CHICAGO TO GAI TO FETCH MAIL AND RUN ERRANDS. MY DEP FROM CHICAGO WAS DELAYED BECAUSE I HAD TO CLR SNOW FROM THE AIRPLANE AND I NEEDED AN APU START BECAUSE THE BATTERY WAS LOW FROM THE BITTER COLD. THE EBOUND TRIP WAS UNEVENTFUL; BUT I WAS ABOUT 1 HR BEHIND SCHEDULE. AMONG THE MAIL I FETCHED WAS A NOTICE FROM THE FAA INFORMING ME OF A 30-DAY SUSPENSION FOR A MINOR VIOLATION IN THE DC ADIZ. IN ADDITION; THE FORECAST FOR THE RETURN TRIP TO CHICAGO INCLUDED LIGHT SNOW AND I DIDN'T WANT TO ARRIVE AFTER DARK. I ELECTED TO FLY TO GYY INSTEAD OF MDW. CLRNC DELIVERY ASKED WHEN I'D BE READY TO GO; AND I RESPONDED WITH 'IMMEDIATELY.' I BEGAN REPROGRAMMING THE GPS'S (INTERRUPTED ROUTINE) AND THE CTLR RELEASED ME ALMOST IMMEDIATELY. I TOOK OFF WITHOUT FULLY COMPLETING MY PREDEP CHKLIST; IE; I DID NOT ENTER THE CORRECT SQUAWK CODE IN THE XPONDERS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CALLBACK ELICITED VERY LITTLE ADDITIONAL INFO. HE DID REVIEW HIS BACKGND AS A HIGH LEVEL MIL OPERATIVE WITH MANY SECURITY CLRNCS AS WELL AS HIS MORE LIMITED EXPOSURE TO GA FLYING; PRIMARILY IN COMPARATIVELY HIGH PERFORMANCE PISTON TWINS. THE ACFT IN QUESTION WAS NEW TO HIM AND THE VIOLATION OCCURRED IN PART BECAUSE OF UNFAMILIARITY WITH THE NAV/COM SYS; IN PARTICULAR; THE DUAL XPONDERS. HE ELABORATED ON HIS FIRST VIOLATION OF THE DC ADIZ WHICH DID; IN FACT; RESULT IN A 30-DAY SUSPENSION FROM THE FAA. HE ADVISED THAT NO ASRS RPT WAS FILED IN THAT INSTANCE.