PA28 PLT; UTILIZING GPS FOR NAV; MISTAKES R-4009 OUTLINE SYMBOL FOR THE EXPANDED MODE OF THE UNDERLYING P-40. INCURSION ENSUES.

Narrative

ON THE AFTERNOON OF MAR/SAT/06; I DEPARTED MD24 ARPT ON A VFR ADIZ FLT PLAN ENRTE TO HGR; MD. MY ADIZ PLAN WAS CLOSED BY ATC UPON LEAVING THE ADIZ BOUNDARY. I WAS AWARE THAT MY INTENDED ROUTING TOOK ME CLOSE TO THE PROHIBITED AIRSPACE AROUND CAMP DAVID (P40); AND I WAS AWARE THAT ON THIS DAY THIS AIRSPACE HAD BEEN 'EXPANDED.' FOR NAV; I WAS USING A GARMIN 196 GPS WHICH I HAD RECENTLY PURCHASED FROM A FRIEND. I NOTED THAT THE GPS DEPICTED THE AIRSPACE AROUND CAMP DAVID AS 2 CONCENTRIC CIRCLES. I THEN MADE MY ERROR. I MADE THE ERRONEOUS ASSUMPTION THAT THE INNER CIRCLE WAS THE NORMAL RESTR AREA AND THAT THE OUTER CIRCLE WAS THE EXPANDED SPACE. I ADDED AN ESTIMATED 3-4 MI BUFFER SPACE TO THIS OUTER CIRCLE AND THOUGHT I WAS PROCEEDING BY CAMP DAVID WELL CLR OF THE RESTR SPACE. UPON RPTING IN TO THE HGR CTL TWR; TO MY SURPRISE; I WAS TOLD THAT I WAS INSIDE THE EXPANDED AIRSPACE AND I WAS GIVEN A HDG TO PROCEED OUT OF THE AIRSPACE. I IMMEDIATELY PROCEEDED ON THAT HDG AND LEFT THE RESTR AIRSPACE. UPON LNDG; I WAS CONTACTED BY THE TWR AND GIVEN A TELEPHONE NUMBER TO CALL (FAA) -- WHICH I DID. I WAS THEN ASKED TO REMAIN WITH THE AIRPLANE UNTIL THE POLICE AND A SECRET SVC REPRESENTATIVE ARRIVED TO INTERVIEW ME. THE INTERVIEWS WENT WELL FOR ME. AT SOMETIME DURING THIS PROCESS; I WAS TOLD THAT I WAS ABOUT 2 MI INTO THE RESTR AIRSPACE. I WAS GIVEN THE OPPORTUNITY TO TURN ON MY GPS AND SHOW THE SECRET SVC MAN THE AIRSPACE DEPICTION AND WHAT I HAD DONE. BY TELEPHONE; HE CHKED MY EXPLANATION AND TRACK WITH WHAT WAS APPARENTLY A RADAR OP PERSON AT CAMP DAVID; AND EVERYTHING CHKED OUT WELL. I HEARD HIM ULTIMATELY TELL ANOTHER PERSON (I ASSUMED HIS SUPERIOR) BY CELL PHONE THAT HE BELIEVED ME; AND I WAS THEN RELEASED TO PROCEED WITH MY INTENDED BUSINESS IN HAGERSTOWN. I FEEL I WAS TREATED WELL BY ALL INVOLVED. I TOLD THEM THAT I RESPECTED WHAT THEY WERE DOING AND THAT I WAS VERY SORRY I HAD BEEN ONE TO COMMIT THIS VIOLATION. AT SOME TIME DURING THE DISCUSSION PROCESS; I LEARNED THAT THE CONCENTRIC CIRCLES ON MY GPS WERE ACTUALLY 3 MI AND 5 MI RADIUS CIRCLES AROUND CAMP DAVID; AND THAT THE EXPANDED AIRSPACE IS A 10 MI RADIUS AND IS NOT SHOWN ON MY GPS. THIS CHECKS WELL WITH THE 3-4 MI BUFFER I THOUGHT I WAS GIVING MYSELF. HOWEVER; TO ASSURE THAT THIS; OR A SIMILAR INCIDENT; DOES NOT HAPPEN TO ME AGAIN; I NEED TO BE AWARE OF EXACTLY WHAT MY GPS IS SHOWING ME -- PARTICULARLY WITH REGARD TO RESTR AIRSPACE. I NEED TO BE AWARE OF THE ACTUAL DIMENSIONS OF THE RESTR AIRSPACE; AND BE ABLE TO COMPARE THIS WITH THE SCALE OF THE AIRSPACE DIMENSIONS SHOWN ON THE GPS.