UNAUTH LNDG ON CLOSED RWY.

Narrative

RETURNING TO ALEXANDRIA ARPT; NJ; FROM FLT TO MMU; NJ ARPT HAD BEEN NOTAMED CLOSED RWY 25 DURING MY ABSENCE (THAT MORNING) FOR SURVEY. NO 'X' ON RWY VISIBLE. RADIOS FAILED IN FLT; SO NO COM TO DISCOVER CLOSING. FOUND OUT AFTER LNDG. I SHOULD HAVE CALLED FSS FOR INFO PRIOR TO RETURN; BUT NEVER EXPECTED RWY TO CLOSE DURING MY ABSENCE. ARPT RADIO AND OFFICE OPERATOR SAID HE DISCOVERED THE CREW WERE DOING THE SURVEY WHEN HE ARRIVED TO OPEN THE OFFICE AND HAD NOT BEEN INFORMED OF THE SCHEDULED WORK BY THE OWNER UNTIL THE MORNING OF THE SURVEY CREW'S ARRIVAL. IF I HAD CHKED FSS FOR NOTAMS OR IF THE RWY HAD HAD A LARGE 'X' ON IT; THE INCIDENT COULD HAVE BEEN AVOIDED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR SAYS; 'I LEARNED ABOUT FLYING FROM THIS--AND AFTER 20000 HRS OF FLYING.' NO NOTICE HAD BEEN GIVEN AT THE ARPT AND THIS WAS A NO RADIO SITUATION; SO NO CHANCE FOR UNICOM TO WARN PLT. TRNING FLT WITH DEP 4 HRS EARLIER. FORTUNATELY SURVEY CREW WAS NOT ON RWY AT TIME OF LNDG. NO MARKINGS ON RWY. SMALL COUNTRY ARPT.