Narrative:

I received a call from my brother-in-law, who had a phone call from a controller at hagerstown, md airport. He wanted to know who was flying his airplane oct/sat/03. He went on to say that this plane had busted the tfr for P40 which was at 10 mi for that day. I explained that my son and I had departed hgr to return to fdk. After departing the airport, we took up a heading of 180 degrees for 10 mi, then a heading of 150 degrees to cross over the mountains and direct to fdk. At no time did I get any calls on the radio and I was not intercepted. The controller from hgr said he had contacted potomac approach and ZDC and they were not tracking me. I've taken this route many times in the past and had no problems. I use a garmin 430 for position awareness and it showed me at 13 mi from the center of P40. When P40 is at 10 mi there is no precision way to determine where the lines are drawn. If there were some kind of beacon that gave DME, that would be great. I know that won't happen. If there were some landmarks, that might help. This wkend I plan to fly over to hgr and ask the tower to xchk my position as I approach the class D airspace and see if there is a big difference with my GPS. There are a few places where I don't get good coverage.

Google
 

Original NASA ASRS Text

Title: A PA23 PLT IS ADVISED THAT, DURING A VFR DEP FROM HGR, HE HAD PENETRATED THE 10 MI PROHIBITED AREA W OF P40, MD.

Narrative: I RECEIVED A CALL FROM MY BROTHER-IN-LAW, WHO HAD A PHONE CALL FROM A CTLR AT HAGERSTOWN, MD ARPT. HE WANTED TO KNOW WHO WAS FLYING HIS AIRPLANE OCT/SAT/03. HE WENT ON TO SAY THAT THIS PLANE HAD BUSTED THE TFR FOR P40 WHICH WAS AT 10 MI FOR THAT DAY. I EXPLAINED THAT MY SON AND I HAD DEPARTED HGR TO RETURN TO FDK. AFTER DEPARTING THE ARPT, WE TOOK UP A HDG OF 180 DEGS FOR 10 MI, THEN A HDG OF 150 DEGS TO CROSS OVER THE MOUNTAINS AND DIRECT TO FDK. AT NO TIME DID I GET ANY CALLS ON THE RADIO AND I WAS NOT INTERCEPTED. THE CTLR FROM HGR SAID HE HAD CONTACTED POTOMAC APCH AND ZDC AND THEY WERE NOT TRACKING ME. I'VE TAKEN THIS RTE MANY TIMES IN THE PAST AND HAD NO PROBS. I USE A GARMIN 430 FOR POS AWARENESS AND IT SHOWED ME AT 13 MI FROM THE CENTER OF P40. WHEN P40 IS AT 10 MI THERE IS NO PRECISION WAY TO DETERMINE WHERE THE LINES ARE DRAWN. IF THERE WERE SOME KIND OF BEACON THAT GAVE DME, THAT WOULD BE GREAT. I KNOW THAT WON'T HAPPEN. IF THERE WERE SOME LANDMARKS, THAT MIGHT HELP. THIS WKEND I PLAN TO FLY OVER TO HGR AND ASK THE TWR TO XCHK MY POS AS I APCH THE CLASS D AIRSPACE AND SEE IF THERE IS A BIG DIFFERENCE WITH MY GPS. THERE ARE A FEW PLACES WHERE I DON'T GET GOOD COVERAGE.

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.