PA-28R pilot began to lose communications while within the washington sfra; he advised ATC in the bl...

Narrative:

Arrived for the day's flight and found the master switch had been left (could still hear turn coordinator.) we; thus; used a battery cart to start the aircraft and all indications were normal during a 10 minute ground run.later; in VFR cruise flight; I first noticed I couldn't hear the PNF and suspected the headset but shortly heard ATC communications. I then started to troubleshoot when the avionics displays started flashing. I immediately advised ATC of a possible electrical failure; and stated my plan to continue east; out of the sfra; and land at a nearby airport. I then secured all electrical loads except the transponder and one radio (now blank; but still receiving) and made calls; apparently in the blind; to ATC. Approximately five miles from landing I attempted to contact ATC via cell phone but was unsuccessful.I then concentrated on making a NORDO visual approach to my diversion airport; landed without incident and immediately cell-phoned ATC to give a 'safe on deck' report. I was met later by a sheriff's deputy sent by ATC to confirm my safe on deck report. I then called the command center to ensure there were no issues due to loss of communications in the sfra.maintenance inspection found fault with the alternator's field wire as the battery was fully charged. The aircraft was returned to service with no further issues.

Original NASA ASRS Text

Title: PA-28R pilot began to lose communications while within the Washington SFRA; he advised ATC in the blind and exited the SFRA to land at a nearby diversion airport.

Narrative: Arrived for the day's flight and found the master switch had been left (could still hear turn coordinator.) We; thus; used a battery cart to start the aircraft and all indications were normal during a 10 minute ground run.Later; in VFR cruise flight; I first noticed I couldn't hear the PNF and suspected the headset but shortly heard ATC communications. I then started to troubleshoot when the avionics displays started flashing. I immediately advised ATC of a possible electrical failure; and stated my plan to continue east; out of the SFRA; and land at a nearby airport. I then secured all electrical loads except the transponder and one radio (now blank; but still receiving) and made calls; apparently in the blind; to ATC. Approximately five miles from landing I attempted to contact ATC via cell phone but was unsuccessful.I then concentrated on making a NORDO visual approach to my diversion airport; landed without incident and immediately cell-phoned ATC to give a 'safe on deck' report. I was met later by a sheriff's deputy sent by ATC to confirm my safe on deck report. I then called the Command Center to ensure there were no issues due to loss of communications in the SFRA.Maintenance inspection found fault with the alternator's field wire as the battery was fully charged. The aircraft was returned to service with no further issues.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1090312
Time
Date	201305
Local Time Of Day	1201-1800
Place
Locale Reference	ANP.Airport
State Reference	MD
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Flight Instructor Flight Crew Commercial Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 30 Flight Crew Total 2800 Flight Crew Type 40
Events
Anomaly	Aircraft Equipment Problem Critical

PA-28R pilot began to lose communications while within the washington sfra; he advised ATC in the blind and exited the sfra to land at a nearby diversion airport.