Narrative:

I began the ILS to runway 27 to hagerstown, washington county airport, on a part 135 flight. Tower reported visibility as 1/2 mi, which was plenty for the approach per the dec/xx/94 approach chart I was using. The approach chart showed 1/2 mi as the minimum. Upon landing, I reviewed a NOTAM obtained from a computerized WX service and noticed that the visibility required for the approach was 3/4 mi. The increased visibility was buried inside 8-10 lines of changes to the approach. I just missed it. Upon checking with a pilot who uses another type of chart, I saw that his chart, issued nov/yy/94 (almost a full month before the current chart) already had the change noted. Most people don't check the NOTAMS for my type of charts unless they're taking a chkride. It is easy to miss this and violate a regulation unwittingly. Actual visibility at decision ht was less than 1 mi. If this were a part 91 flight, there would not have been a problem. However, under part 135, an approach cannot be initiated unless visibility is at or above minimums, which in this case was 3/4 mi. Note: I did have my type of chart NOTAM in my possession during the approach and had reviewed it before the flight. However, the increased visibility and decision ht were 'buried' inside numerous other changes and I just overlooked it.

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Original NASA ASRS Text

Title: BELOW MINIMUMS IFR APCH.

Narrative: I BEGAN THE ILS TO RWY 27 TO HAGERSTOWN, WASHINGTON COUNTY ARPT, ON A PART 135 FLT. TWR RPTED VISIBILITY AS 1/2 MI, WHICH WAS PLENTY FOR THE APCH PER THE DEC/XX/94 APCH CHART I WAS USING. THE APCH CHART SHOWED 1/2 MI AS THE MINIMUM. UPON LNDG, I REVIEWED A NOTAM OBTAINED FROM A COMPUTERIZED WX SVC AND NOTICED THAT THE VISIBILITY REQUIRED FOR THE APCH WAS 3/4 MI. THE INCREASED VISIBILITY WAS BURIED INSIDE 8-10 LINES OF CHANGES TO THE APCH. I JUST MISSED IT. UPON CHKING WITH A PLT WHO USES ANOTHER TYPE OF CHART, I SAW THAT HIS CHART, ISSUED NOV/YY/94 (ALMOST A FULL MONTH BEFORE THE CURRENT CHART) ALREADY HAD THE CHANGE NOTED. MOST PEOPLE DON'T CHK THE NOTAMS FOR MY TYPE OF CHARTS UNLESS THEY'RE TAKING A CHKRIDE. IT IS EASY TO MISS THIS AND VIOLATE A REG UNWITTINGLY. ACTUAL VISIBILITY AT DECISION HT WAS LESS THAN 1 MI. IF THIS WERE A PART 91 FLT, THERE WOULD NOT HAVE BEEN A PROB. HOWEVER, UNDER PART 135, AN APCH CANNOT BE INITIATED UNLESS VISIBILITY IS AT OR ABOVE MINIMUMS, WHICH IN THIS CASE WAS 3/4 MI. NOTE: I DID HAVE MY TYPE OF CHART NOTAM IN MY POSSESSION DURING THE APCH AND HAD REVIEWED IT BEFORE THE FLT. HOWEVER, THE INCREASED VISIBILITY AND DECISION HT WERE 'BURIED' INSIDE NUMEROUS OTHER CHANGES AND I JUST OVERLOOKED IT.

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.