Narrative:

Reference 121.652 far for high minimums capts it was interpreted that the mdo or DH and visibility requirements must be increased by 100' and 1/2 mi or RVR equivalent. In executing the ILS runway 9 at dlh the DH was increased by 100' and RVR value was 6000' plus. Therefore, 300' hat and visibility equivalent in excess of 1 mi. What was misconstrued was the requirement of a controling ceiling height as well as a controling visibility value to continue the approach beyond the final approach fix. It is believed that a clarification in the wording of this particular regulation to read 'in no event may the landing WX minimums be less than 300' and 1', rather than 'landing minimums' solely, would allow a more concise interpretation of its meaning.

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Original NASA ASRS Text

Title: COMMUTER LTT FAILED TO OBSERVE HIGHER ARPT LNDG MINIMUMS FOR LESS THAN 100 HR CAPT ON AN APCH LNDG AT DLH.

Narrative: REFERENCE 121.652 FAR FOR HIGH MINIMUMS CAPTS IT WAS INTERPRETED THAT THE MDO OR DH AND VISIBILITY REQUIREMENTS MUST BE INCREASED BY 100' AND 1/2 MI OR RVR EQUIVALENT. IN EXECUTING THE ILS RWY 9 AT DLH THE DH WAS INCREASED BY 100' AND RVR VALUE WAS 6000' PLUS. THEREFORE, 300' HAT AND VISIBILITY EQUIVALENT IN EXCESS OF 1 MI. WHAT WAS MISCONSTRUED WAS THE REQUIREMENT OF A CTLING CEILING HEIGHT AS WELL AS A CTLING VISIBILITY VALUE TO CONTINUE THE APCH BEYOND THE FINAL APCH FIX. IT IS BELIEVED THAT A CLARIFICATION IN THE WORDING OF THIS PARTICULAR REG TO READ 'IN NO EVENT MAY THE LNDG WX MINIMUMS BE LESS THAN 300' AND 1', RATHER THAN 'LNDG MINIMUMS' SOLELY, WOULD ALLOW A MORE CONCISE INTERPRETATION OF ITS MEANING.

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.