PA-28R Cherokee Arrow All Series
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 25; Flight Crew Total 10065; Flight Crew Type 35
Confusion
Aircraft Equipment Problem Less Severe
General None Reported / Taken
Aircraft
While on a VFR flight to Morristown Municipal (MMU); my GPS showed I was 8 miles out at 1500 feet from Morristown Municipal Airport when I radio the Tower Control to announce my intentions to land full stop; ATC cleared me for left downwind Runway 31 and report mid field downwind then asked me to ident. After I idented ATC indicated I was 5 miles south; which still puts me outside of the Class D airspace at the time I checked in with ATC since the Class D airspace at Morristown Municipal is within 4.1 NM radius of the airport according to FAA Order JO 7400.9Y date August 06; 2014 page 223.I feel the GPS was misleading me and want to make sure this information is documented in case there is a bad GPS signal in the area and other pilots report the same situation in the area in the future.
PA28 pilot reports checking in with MMU Tower 8 NM out; according to his GPS; then told to ident. The Tower indicates that he is 5 NM south and the reporter believes that there may be a bad GPS signal in this area.