Narrative:

I was navigating around the tfr around P40 to the north and northwest. I genuinely believed I was well clear of the tfr, and I did not even second-guess my position. I landed at mrb and was informed by the ground controller to call a phone number. I called and was informed that I entered the 10 mi tfr by 1.5 mi, 8.5 mi away from P40's center. I did not intentionally penetrate the tfr. After learning of my error, I wondered why I did not get a warning over 121.5 guard frequency. I simply was not where I thought I was. I will be more careful in the future.

Google
 

Original NASA ASRS Text

Title: PLT OF PA31 ON AERIAL SURVEY FLT N OF DC ADIZ PENETRATES P40 AIRSPACE.

Narrative: I WAS NAVING AROUND THE TFR AROUND P40 TO THE N AND NW. I GENUINELY BELIEVED I WAS WELL CLR OF THE TFR, AND I DID NOT EVEN SECOND-GUESS MY POS. I LANDED AT MRB AND WAS INFORMED BY THE GND CTLR TO CALL A PHONE NUMBER. I CALLED AND WAS INFORMED THAT I ENTERED THE 10 MI TFR BY 1.5 MI, 8.5 MI AWAY FROM P40'S CTR. I DID NOT INTENTIONALLY PENETRATE THE TFR. AFTER LEARNING OF MY ERROR, I WONDERED WHY I DID NOT GET A WARNING OVER 121.5 GUARD FREQ. I SIMPLY WAS NOT WHERE I THOUGHT I WAS. I WILL BE MORE CAREFUL IN THE FUTURE.

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.