PIERRE, (KCCR) — Two Denver Air Connection flights from Pierre to the Mile High City were scrubbed at the end of last week because of an odd issue at Pierre Regional Airport. A sensor which measures visibility failed on the airport’s Automated Weather Observation Station or AWOS. A new sensor arrived in Pierre Friday and was installed late Friday afternoon. A certified weather observer was also sent to Pierre to make manual observations of weather conditions until the AWOS was operating again. The Federal Aviation Administration requires all Part 121 and 135 operators to use approved sources of weather reports and meteorological conditions at any airport where Instrument Flight Rules or I-F-R departures or approaches are used. That explains why even on clear and blue, sky day, commercial flights could not take off. Flights resumed from Pierre Regional Airport after a new sensor was installed and tested.