CTLR AND FLT CREW DESCRIBE IFR DEP FROM CLOSED ARPT; CLAIMING LACK AND CONFUSED INFO REGARDING ARPT STATUS; NO FAA INFO RECORDED.

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I HAD JUST OPENED SATELLITE POS. I HEARD SOMETHING ON FREQ BUT IT WAS GARBLED. SOON AFTER THAT AN ACFT CALLED FOR AN IFR CLRNC. THE ARPT WAS NOTAMED CLOSED. I ADVISED PLT OF NOTAM. SOMEONE THEN SAID ON FREQ THAT 'IT'S OPEN.' I ISSUED ACFT X HIS CLRNC; HE READ IT BACK AND SAID HE WAS READY; OFF RWY 14. I RELEASED HIM. RIGHT AFTER THAT PERSONNEL AT ZZZ RADIOED THAT THE ARPT WAS STILL CLOSED UNTIL XA00 AM. I ASKED ACFT X IF THEY HEARD THAT AND NO RESPONSE. PERSONNEL THEN REITERATED THAT ARPT WAS CLOSED AND THAT THE ACFT WAS TAKING OFF AT HIS OWN RISK. ACFT THEN RPTED AIRBORNE AND I RPTED TO PERSONNEL AT ZZZ THAT ACFT WAS NO FACTOR. I AM NOT SURE WHO SAID THAT THE ARPT WAS OPEN. I SHOULD HAVE MADE SURE OF WHO IT WAS THAT SAID THAT. ALSO AFTER ISSUING THE NOTAM TO THE PLT; IS IT THEN UP TO HIM TO DEPART WHEN THE ARPT IS OPEN? (NO VOID TIME GIVEN) THEY ARE ALSO CALLING A PLTDEV ON THE PLT. SUPPLEMENTAL INFO FROM ACN 757595: AFTER LISTENING TO THE ARPT ASOS; I STARTED TAXIING OUT TO THE ACTIVE RWY 14. AS I APCHED THE TXWY FROM THE FBO; I SAW THAT THE ARPT RWY AND TXWY LIGHTS WERE OUT. I LISTENED TO THE ASOS AGAIN; AND HEARD NO MENTION OF AN ARPT CLOSURE. I TURNED THE ACFT AROUND TO GO BACK TO THE FBO TO CHK OUT THE SITUATION. AS I WAS GOING BACK TO THE FBO; THE ARPT TXWY AND RWY LIGHTS CAME ON. I TOOK THIS TO BE A SIGN THAT THE ARPT WAS OPEN FOR BUSINESS. I TAXIED TO RWY 14; AND RECEIVED MY CLRNC ON THE WAY. MINNEAPOLIS CLRNC DELIVERY MENTIONED A NOTAM FOR AN ARPT CLOSURE. I TOLD THE CTLR THAT THERE WAS NO MENTION OF THE CLOSURE ON THE ASOS; AND TOLD HIM THAT THE LIGHTS WERE NOW ON AT THE ARPT. HE GAVE ME MY RTE CLRNC AND MY DEP RELEASE. I TOOK OFF UNEVENTFULLY; AND WAS UNAWARE OF ANY PROB UNTIL MINNEAPOLIS DEP GAVE ME A PHONE NUMBER TO CALL. I CALLED THE NUMBER AND WAS INFORMED THAT A PRELIMINARY INVESTIGATION WAS IN PROGRESS FOR A RWY INCURSION. I FEEL THAT THE ARPT CLOSURE NOTAM SHOULD HAVE DEFINITELY BEEN INCLUDED IN THE NOTAM RPT ON THE ASOS. IF THAT HAD BEEN THE CASE; THIS INCIDENT WOULD NOT HAVE HAPPENED. FURTHER; MAINT PERSONNEL ON THE GND SHOULD MONITOR THE ARPT'S CTAF TO ENSURE THAT PLTS CAN BE WARNED PRIOR TO TAKING A RWY WHERE MAINT MAY OR MAY NOT BE IN PROGRESS.