Narrative:

Flying from W99 to 1n9. Received NOTAM information for route of flight from fs; including expanded P40. Filed VFR flight plan. Using an IFR GPS; VOR; handheld GPS and current sectional for navigation. 5 mi southwest of frederick; the handheld failed and the VOR swung wildly as if to indicate over VOR. Panel mount GPS showed still on course and 5 mi out. Varied course 1 min or less to ascertain VOR and GPS status and noted location on sectional as just past the harper's ferry bridges. I turned off the failed handheld. Panel mount GPS includes 2 concentric circles around P40; which I assumed were the standard and expanded areas. I was clear the outer ring by several mi according to the GPS and no alert showed on the screen. Continued past frederick on same heading and was intercepted by a secret service helicopter about 2-5 mi ene of frederick. Was informed on 121.5 that I was within the tfr. I informed them that my multiple navigation showed me clear and asked what I was to do. Got no response as to what action ws to be taken; so continued on course. Helicopter followed me for 5-10 mins and broke off. Called secret service at destination as requested. They said I was 2 mi inside the tfr according to ZDC. They also notified me that the sectional did not actually show the correct boundaries of the tfr. I later was told by another pilot that the database is also not correct for the expanded P40; even though both circles show on the map. I was not aware of either of these discrepancies in mapping on that day.

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Original NASA ASRS Text

Title: THE PLT OF A C172 FLIES INTO EXPANDED P40; A TFR AROUND CAMP DAVID. THE DEPICTION OF P40 ON HIS GPS IN NOT ACCURATE.

Narrative: FLYING FROM W99 TO 1N9. RECEIVED NOTAM INFO FOR RTE OF FLT FROM FS; INCLUDING EXPANDED P40. FILED VFR FLT PLAN. USING AN IFR GPS; VOR; HANDHELD GPS AND CURRENT SECTIONAL FOR NAV. 5 MI SW OF FREDERICK; THE HANDHELD FAILED AND THE VOR SWUNG WILDLY AS IF TO INDICATE OVER VOR. PANEL MOUNT GPS SHOWED STILL ON COURSE AND 5 MI OUT. VARIED COURSE 1 MIN OR LESS TO ASCERTAIN VOR AND GPS STATUS AND NOTED LOCATION ON SECTIONAL AS JUST PAST THE HARPER'S FERRY BRIDGES. I TURNED OFF THE FAILED HANDHELD. PANEL MOUNT GPS INCLUDES 2 CONCENTRIC CIRCLES AROUND P40; WHICH I ASSUMED WERE THE STANDARD AND EXPANDED AREAS. I WAS CLR THE OUTER RING BY SEVERAL MI ACCORDING TO THE GPS AND NO ALERT SHOWED ON THE SCREEN. CONTINUED PAST FREDERICK ON SAME HDG AND WAS INTERCEPTED BY A SECRET SVC HELI ABOUT 2-5 MI ENE OF FREDERICK. WAS INFORMED ON 121.5 THAT I WAS WITHIN THE TFR. I INFORMED THEM THAT MY MULTIPLE NAV SHOWED ME CLR AND ASKED WHAT I WAS TO DO. GOT NO RESPONSE AS TO WHAT ACTION WS TO BE TAKEN; SO CONTINUED ON COURSE. HELI FOLLOWED ME FOR 5-10 MINS AND BROKE OFF. CALLED SECRET SVC AT DEST AS REQUESTED. THEY SAID I WAS 2 MI INSIDE THE TFR ACCORDING TO ZDC. THEY ALSO NOTIFIED ME THAT THE SECTIONAL DID NOT ACTUALLY SHOW THE CORRECT BOUNDARIES OF THE TFR. I LATER WAS TOLD BY ANOTHER PLT THAT THE DATABASE IS ALSO NOT CORRECT FOR THE EXPANDED P40; EVEN THOUGH BOTH CIRCLES SHOW ON THE MAP. I WAS NOT AWARE OF EITHER OF THESE DISCREPANCIES IN MAPPING ON THAT DAY.

Data retrieved from NASA's ASRS site as of January 2009 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.