A C172 VIOLATED THE DCA ADIZ BECAUSE OF A VOR FAILURE.

Narrative

FOR A TRIP FROM MY HOME ARPT ZZZ TO CBE (CUMBERLAND; MD) I OBTAINED A WX BRIEFING; INCLUDING NOTAMS AND FILED A FLT PLAN PRIOR TO DEP. RTE WAS PLOTTED FROM ZZZ TO WESTMINSTER VOR; AND FROM THERE TO CBE. DEPARTED ZZZ AND CONTACTED JYO FSS ON 122.2 SOON THEREAFTER TO OPEN FLT PLAN. CRUISING ALT WAS 2500 FT. TUNED VOR TO EMI 117.9; BUT COULD ONLY GET THE 'OFF' FLAG; COULD NOT GET THE AUDIBLE IDENT CODE EITHER. THOUGHT MAYBE TOO FAR AWAY; SO MAINTAINED HDG AND KEPT TRYING TO GET THE NEEDLE TO RESPOND. STARTED CHKING FOR LANDMARKS AND PASSED OVER I-83. BECAME CONCERNED ABOUT P-40 INTRUSION; SO I DECIDED TO BEAR SLIGHTLY S TO FOLLOW I-70 WHICH WOULD SAFELY SKIRT P-40. DID NOT LOCATE I-70; BUT INSTEAD PASSED ANOTHER MAJOR N-S HWY WHICH I THOUGHT WAS I-795. THIS WOULD HAVE PUT ME EVEN CLOSER TO P-40; BUT PRETTY MUCH W OF ADIZ; SO I ADJUSTED COURSE EVEN FURTHER S IN A VAIN ATTEMPT TO LOCATE I-70 AND FREDERICK; MD. INSTEAD; I KEPT PASSING UNFAMILIAR N-2 HWYS; BUT TRIED TO MAINTAIN A PATH WELL N OF SUBURBAN AREAS AND STAY OVER GREEN; UNDEVELOPED AREAS. IT WAS AT THIS POINT THAT I SAW RED AND GREEN FLASHING LIGHTS COMING FROM ATOP A BUILDING TO THE S. HAVING READ ADVISORIES ABOUT THIS WARNING SYS; I KNEW THAT IT MEANT TO TURN BACK; SO I CHANGED COURSE TO NW. ALTHOUGH I KNEW THE LIGHT MEANT TROUBLE AND THAT I WAS TOO CLOSE; I ACTUALLY FELT RELIEF THAT I HAD BEEN WARNED OFF BY THE LIGHT; STILL THINKING THAT I WAS SAFELY N OF THE ADIZ SOMEWHERE NEAR FREDERICK. THEN I SPOTTED A LARGE; MULTI-RWY ARPT THAT I THOUGHT MIGHT BE JYO BUT THE RWYS DID NOT MATCH. STILL WARY OF PENETRATING P-40 I DID NOT WANT TO VENTURE TOO FAR N; SO I CONTINUED IN A WESTERLY DIRECTION WHEN I ENCOUNTERED THE POTOMAC RIVER. I STARTED FOLLOWING THIS AS I KNEW IT WOULD EVENTUALLY LEAD ME TO I-70 OR I-68; AND SAFELY KEEPING ME AWAY FROM P-40; AND EVENTUALLY TO CBE. WHAT SEEMED LIKE MINS AFTER I STARTED FOLLOWING THE POTOMAC; A HOMELAND SECURITY CHOPPER IMMEDIATELY APPEARED OFF MY L WING. IT WAS THEN THAT I REALIZED THAT I HAD ACTUALLY ENTERED THE ADIZ WITHOUT AUTHORIZATION. I CONTACTED JYO FSS ON 122.2; WHICH WAS STILL DIALED IN ON MY RADIO. IN THE MIDST OF HAVING TROUBLE EXPLAINING MY PREDICAMENT AND HAVING FSS PERSONNEL COMPREHEND WHAT I WAS RELATING; I NOTICED '121.5.' ON THE CHOPPER'S NOSE. SO I IMMEDIATELY SWITCHED TO THE EMER CHANNEL AND GOT THE CHOPPER RIGHT AWAY. I EXPLAINED THAT I WAS LOST WITH AN INOP VOR. THE CHOPPER ASKED ME TO GO TO JYO AND PROVIDED A VECTOR. THEY ALSO ASSISTED BY MAKING RADIO CALLS FOR ME IN THE PATTERN. I LANDED UNEVENTFULLY AND TAXIED UP TO FBO AS INSTRUCTED. AFTER TALKING TO THE REQUIRED PERSONNEL; I REQUESTED AND WENT UP WITH A LCL FLT INSTRUCTOR TO SEE IF SHE COULD FIGURE OUT THE VOR. SHE VERIFIED THAT IT DID NOT WORK; BRIEFED ME ON ADIZ DEP PROCS; RECOMMENDED THAT I HEAD N TO FREDERICK TO DEPART ADIZ AS QUICKLY AS POSSIBLE AND SKIRT IT TO THE N ON MY WAY BACK TO ZZZ. IF I HAD BEEN ABLE TO GET THE VOR TO WORK; THE INCURSION WOULD NOT HAVE OCCURRED. HOWEVER; AS SOON AS I REALIZED THE VOR WAS NOT WORKING I SHOULD HAVE IMMEDIATELY CONTACTED LEESBURG FSS; WHO WOULD HAVE PUT ME IN TOUCH WITH POTOMAC TRACON. TO PREVENT RECURRENCE IN THE FUTURE; I WILL ALWAYS BE IN CONTACT WITH POTOMAC TRACON ANY TIME I AM EVEN NEAR THE ADIZ.