STUDENT PLT LOST ON SOLO XCOUNTRY.

Narrative

WHILE ENRTE TO CHARLOTTESVILLE; VA; ON THE SECOND LEG OF MY STUDENT LONG SOLO XCOUNTRY; I MISSED MY NAV CHKPOINT OVER FARMVILLE; VA. I NOTICED THE CEILING WAS DECREASING (FROM 2000-1000) AND THE WX WAS DETERIORATING. I NOTICED I HAD BEEN FLYING FOR NEARLY AN HR AND I SHOULD HAVE BEEN OVER MY CHKPOINT AFTER 30 MINS OF FLT. I TRIED CALLING 'RICHMOND APCH' AND WAS UNABLE TO REACH THEM. AN AIRLINE HEARD ME AND BEGAN RELAYING FOR ME. I INFORMED RICHMOND OF MY LAST KNOWN POS AND TIME. RICHMOND DIRECTED ME TO DIAL IN A NUMBER INTO MY XPONDER. I DID SO. DUE TO THE ALT I WAS FLYING; RICHMOND WAS UNABLE TO SEE ME. I MAINTAINED MY COURSE (048) AND RICHMOND KEPT TALKING TO ME THROUGH THE ACR FLT. FINALLY; RICHMOND SWITCHED ME TO DULLES APCH. I INFORMED DULLES APCH OF MY SIT AND EXPLAINED I WAS TRYING TO GET TO CHARLOTTESVILLE. DULLES INFORMED ME THE WX WAS TOO BAD IN CHARLOTTESVILLE; VA. DULLES DIRECTED ME TO DIAL IN A XPONDER CODE AND THEY WERE UNABLE TO SEE ME. SO; DULLES DIRECTED ME TO DIAL IN 7700. NOW THE CEILING WAS BTWN 1000-1500 FT. I WAS STILL TALKING TO DULLES APCH. FINALLY; I SAW A PLANE FLYING OVERHEAD AT ABOUT 1500 FT. I TOLD DULLES I SAW THE ACFT. DULLES INFORMED ME THAT MANASSAS MUNICIPAL ARPT SHOULD BE OFF MY R WING. I SAW THE ARPT AND I LANDED.