A NAVION SINGLE PLT VIOLATED THE DC ADIZ.

Narrative

I DEPARTED 2W6 WITH 1 PAX. I SQUAWKED 1200 CODE MODE C. I LANDED AT CGE AND DEPARTED TO THE W 1 HR LATER. I DECIDED TO FLY JUST S OF LAPLATA TO TAKE PICTURES. I CONTACTED PATUXENT APCH ON 120.05 AND TOLD THEM OF MY INTENTIONS AND ASKED IF I HAD TO DO ANYTHING SPECIAL TO FLY TO LAPLATA AT 1000 FT MSL. THEY CAME BACK WITH 'STAY CLR OF ADIZ.' I DID NOT KNOW THAT I WAS REQUIRED TO FILE A FLT PLAN TO FLY AROUND THE LAPLATA AREA AT 1000 FT. I THOUGHT (AT THAT TIME) THAT I WAS ONLY REQUIRED TO FILE IF I LANDED OR TOOK OFF WITHIN THE ADIZ. I WAS STILL SQUAWKING 1200. I CIRCLED THE PROPERTY JUST S OF LAPLATA TO TAKE THE PICTURES; TURNED OUT TO A NORTHERN HDG; AND THEN MADE A 180 DEG TURN BACK TO THE S TOWARDS 2W6. JUST S OF CHALK POINT PWR PLANT AT 1000 FT; A UNITED STATES CUSTOMS HELI APCHED TO MY R AT THE SAME ALT. I CONTACTED PATUXENT APCH AGAIN AND ASKED THEM IF THE HELI WAS TRYING TO CONTACT ME. THEY SAID NOT TO THEIR KNOWLEDGE. AFTER A MIN; THE HELI HELD UP A SIGN WITH THE EMER FREQ ON IT; AND I IMMEDIATELY CONTACTED THEM. I TOLD THEM I WAS LNDG AT 2W6; AND THEY FOLLOWED ME DOWN AND I LANDED AND TAXIED TO PARK. I WAS THEN APCHED BY THE 2 UNITED STATES CUSTOMS AGENTS; WHO TOLD ME OF THE VIOLATION; AND ASKED FOR MY DRIVER'S LICENSE; PLT'S LICENSE; MEDICAL; ACFT REGISTRATION; AND PAX'S DRIVER'S LICENSE. ALL DOCUMENTS WERE PRODUCED TO THE SATISFACTION OF THE CUSTOM'S AGENTS. THEY THEN INSTRUCTED ME TO CONTACT POTOMAC APCH BY TELEPHONE WHEN I GOT HOME. I DID THIS; AND THEY SAID THAT I WOULD BE CONTACTED IN SEVERAL WKS. I HAVE SINCE THEN REVIEWED THE ADIZ REQUIREMENTS IN DETAIL; AND REALIZE THAT I NEED TO FILE A FLT PLAN BEFORE ENTERING THE 30 MI RADIUS OF THE WASHINGTON AREA.