CL-65 CREW QUESTIONS TKOF LEGALITY WITH LOW VISIBILITY RECORDED ON ATIS. LATER; THE CREW FOUND A NOTAM OF INACCURATE WX MEASURING TOOLS AT THE ARPT.

Narrative

WHILE ON THE GND AT HTS; WE RECEIVED THE ATIS. AT THE TIME; NOTHING SEEMED TOO UNUSUAL; BUT THEN WE WERE NOT LOOKING TO FIND ANYTHING UNUSUAL. ATIS RPTED 1/4 MI VISIBILITY TEMP OF 14 DEGS; DEWPOINT 1 DEG WITH HAZE. IT WAS OBVIOUS FOG CONSUMED AREA; BUT AS FAR AS WE WERE CONCERNED; WE WERE LEGAL FOR TKOF. AFTER TKOF; WE REALLY ANALYZED THE ATIS. WITH FOG IN THE AREA; AND A TEMP DEWPOINT SPREAD OF 14/1 WITH HAZE; SOMETHING SEEMED WRONG. WE CAME TO FIND OUT LATER THE WX EQUIP MALFUNCTIONED. FOR TKOF AT THE TIME; THIS DID NOT CROSS OUR MIND. SOMETIMES I FEEL WE PUT TOO MUCH IMPORTANCE ON MACHINES GIVING CORRECT INFO. THIS WAS OUR ERROR. SUPPLEMENTAL INFO FROM ACN 593495: WE WERE THE FIRST FLT OF THE DAY SCHEDULED. THE TWR WAS OPEN. SEVERAL DAYS LATER; WE BECAME AWARE THAT A FEW OF OUR AIRLINE'S CREWS TOOK OFF AND LANDED WITH THE ATIS/WX AT HTS NOTAMED EITHER INOP OR INACCURATE ON THE SAME DAY WE DEPARTED. NEITHER I NOR THE CAPT KNOWS IF THE ATIS/WX WAS NOTAMED INOP OR INACCURATE AT OUR TIME OF DEP. NOTAMS ARE OFTEN HASTILY CHKED OR OVERLOOKED IN THE DISPATCH PAPERWORK.