Commuter makes landing below mins due to change not noted from NOTAMS.

Attributes
ACN	202910
Time
Date	199202
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mhe
State Reference	SD
Altitude	agl bound lower : 0 agl bound upper : 3300
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zmp
Operator	common carrier : air carrier
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Navigation In Use	Other Other
Flight Phase	descent : approach landing other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp pilot : instrument
Experience	flight time last 90 days : 260 flight time total : 2250 flight time type : 255
ASRS Report	202910
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Mhe ILS newly commissioned. AWOS reported visibility had dropped to 1/2 mi. 1/2 mi needed for approach according to approach plate. Completed approach without incident. Captain discovered several days later that fdc NOTAM had raised the min to 3/4 mi, we think because ALS was reported OTS. (They worked). Captain had checked class ii NOTAMS before flight but somehow missed this one. Mhe ILS was installed this summer and NOTAMS for the airport were continually changing -- most of the time we noted inoperative items worked. A good idea to monitor class ii NOTAMS carefully when a new NAVAID or other airport construction going on.

Original NASA ASRS Text

Title: COMMUTER MAKES LNDG BELOW MINS DUE TO CHANGE NOT NOTED FROM NOTAMS.

Narrative: MHE ILS NEWLY COMMISSIONED. AWOS RPTED VISIBILITY HAD DROPPED TO 1/2 MI. 1/2 MI NEEDED FOR APCH ACCORDING TO APCH PLATE. COMPLETED APCH WITHOUT INCIDENT. CAPT DISCOVERED SEVERAL DAYS LATER THAT FDC NOTAM HAD RAISED THE MIN TO 3/4 MI, WE THINK BECAUSE ALS WAS RPTED OTS. (THEY WORKED). CAPT HAD CHKED CLASS II NOTAMS BEFORE FLT BUT SOMEHOW MISSED THIS ONE. MHE ILS WAS INSTALLED THIS SUMMER AND NOTAMS FOR THE ARPT WERE CONTINUALLY CHANGING -- MOST OF THE TIME WE NOTED INOP ITEMS WORKED. A GOOD IDEA TO MONITOR CLASS II NOTAMS CAREFULLY WHEN A NEW NAVAID OR OTHER ARPT CONSTRUCTION GOING ON.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.