|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1801 To 2400|
|Locale Reference||airport : avl|
|Altitude||agl bound lower : 0|
agl bound upper : 2500
|Controlling Facilities||tower : avl|
|Operator||common carrier : air carrier|
|Make Model Name||Large Transport, Low Wing, 3 Turbojet Eng|
|Flight Phase||descent : approach|
landing : go around
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Experience||flight time last 90 days : 200|
flight time total : 15000
|Affiliation||government : faa|
|Function||controller : local|
|Qualification||controller : non radar|
|Anomaly||inflight encounter : weather|
non adherence : far
|Independent Detector||other flight crewa|
|Resolutory Action||none taken : detected after the fact|
|Primary Problem||Flight Crew Human Performance|
|Air Traffic Incident||Pilot Deviation|
The flight was from charlotte to asheville. The departure and destination ceiling and visibility were very low and the flight was scheduled to operate late at night. A game plan of proceeding to a certain alternate was put in place between the captain (me) and the dispatcher. We both knew what we were going to do in the event of not being able to land at avl. We arrived at avl and were told that the visibility was 3/4 mi, legal to initiate the approach to runway 34. At DH I was told the runway was in sight by the copilot and I diverted my attention outside to land. It was a very fuzzy 3/4 mi and knowing avl like I do, decided that the T/D zone was probably ok for landing--our alignment was good and we could safely land in that environment--but beyond the 1000' mark was a big question in my mind: could we stay on the runway once we touched down? I didn't like it so I initiated a go around west/O incident. Once we were established downwind I asked the tower exactly what it looked like, looking out onto the runway from the terminal. He stated that it appeared that most of the poor visibility was on the approach end of the airport, and that a normal rollout appeared to be no problem. I don't like avl anyway because of the mountainous terrain and the night icing situation further jaded my opinion, but decided to give the passenger the benefit of another try. We hooked up the autoplt and shot a monitored approach. The tower was now giving visibility reports in both RVV values and prevailing visibility values. Our approach calls for 1/2 mi forward visibility reference values. Great, just what we needed, but all 3 of us quickly agreed that the order of priority of visibility values is RVR (non available at avl), RVV (a precision instrument for reading visibility) and lastly, prevailing. Just before reaching the final approach fix the tower announced, 'RVV 1/2, prevailing 1/4.' again, we 3 agreed it was in fact legal to shoot the approach again. At minimums (and no lower!!!), we saw nothing and again missed and then proceeded to the alternate west/O incident. I now know that I shot the approach when the WX was below minimums as prevailing overrules RVV. We were looking at 3 values (RVV, prevailing and forward visibility reference) and incorrectly determined the priority. We discussed it later and all 3 of us wondered aloud why it has to be so darned hard to make a legal determination and why does this determination always seem to have to be made at night, IFR, in a mountainous region and in icing conditions? Why can't the FAA resolve this ambiguity? But the final authority to shoot the approach rested with me and I can tell you that I know better now.
Original NASA ASRS Text
Title: IAP ILS APCH IN WX REPORTED BELOW ARPT MINIMUMS FOR LNDG.
Narrative: THE FLT WAS FROM CHARLOTTE TO ASHEVILLE. THE DEP AND DEST CEILING AND VISIBILITY WERE VERY LOW AND THE FLT WAS SCHEDULED TO OPERATE LATE AT NIGHT. A GAME PLAN OF PROCEEDING TO A CERTAIN ALTERNATE WAS PUT IN PLACE BTWN THE CAPT (ME) AND THE DISPATCHER. WE BOTH KNEW WHAT WE WERE GOING TO DO IN THE EVENT OF NOT BEING ABLE TO LAND AT AVL. WE ARRIVED AT AVL AND WERE TOLD THAT THE VISIBILITY WAS 3/4 MI, LEGAL TO INITIATE THE APCH TO RWY 34. AT DH I WAS TOLD THE RWY WAS IN SIGHT BY THE COPLT AND I DIVERTED MY ATTN OUTSIDE TO LAND. IT WAS A VERY FUZZY 3/4 MI AND KNOWING AVL LIKE I DO, DECIDED THAT THE T/D ZONE WAS PROBABLY OK FOR LNDG--OUR ALIGNMENT WAS GOOD AND WE COULD SAFELY LAND IN THAT ENVIRONMENT--BUT BEYOND THE 1000' MARK WAS A BIG QUESTION IN MY MIND: COULD WE STAY ON THE RWY ONCE WE TOUCHED DOWN? I DIDN'T LIKE IT SO I INITIATED A GAR W/O INCIDENT. ONCE WE WERE ESTABLISHED DOWNWIND I ASKED THE TWR EXACTLY WHAT IT LOOKED LIKE, LOOKING OUT ONTO THE RWY FROM THE TERMINAL. HE STATED THAT IT APPEARED THAT MOST OF THE POOR VISIBILITY WAS ON THE APCH END OF THE ARPT, AND THAT A NORMAL ROLLOUT APPEARED TO BE NO PROB. I DON'T LIKE AVL ANYWAY BECAUSE OF THE MOUNTAINOUS TERRAIN AND THE NIGHT ICING SITUATION FURTHER JADED MY OPINION, BUT DECIDED TO GIVE THE PAX THE BENEFIT OF ANOTHER TRY. WE HOOKED UP THE AUTOPLT AND SHOT A MONITORED APCH. THE TWR WAS NOW GIVING VISIBILITY RPTS IN BOTH RVV VALUES AND PREVAILING VISIBILITY VALUES. OUR APCH CALLS FOR 1/2 MI FORWARD VISIBILITY REFERENCE VALUES. GREAT, JUST WHAT WE NEEDED, BUT ALL 3 OF US QUICKLY AGREED THAT THE ORDER OF PRIORITY OF VISIBILITY VALUES IS RVR (NON AVAILABLE AT AVL), RVV (A PRECISION INSTRUMENT FOR READING VISIBILITY) AND LASTLY, PREVAILING. JUST BEFORE REACHING THE FINAL APCH FIX THE TWR ANNOUNCED, 'RVV 1/2, PREVAILING 1/4.' AGAIN, WE 3 AGREED IT WAS IN FACT LEGAL TO SHOOT THE APCH AGAIN. AT MINIMUMS (AND NO LOWER!!!), WE SAW NOTHING AND AGAIN MISSED AND THEN PROCEEDED TO THE ALTERNATE W/O INCIDENT. I NOW KNOW THAT I SHOT THE APCH WHEN THE WX WAS BELOW MINIMUMS AS PREVAILING OVERRULES RVV. WE WERE LOOKING AT 3 VALUES (RVV, PREVAILING AND FORWARD VISIBILITY REF) AND INCORRECTLY DETERMINED THE PRIORITY. WE DISCUSSED IT LATER AND ALL 3 OF US WONDERED ALOUD WHY IT HAS TO BE SO DARNED HARD TO MAKE A LEGAL DETERMINATION AND WHY DOES THIS DETERMINATION ALWAYS SEEM TO HAVE TO BE MADE AT NIGHT, IFR, IN A MOUNTAINOUS REGION AND IN ICING CONDITIONS? WHY CAN'T THE FAA RESOLVE THIS AMBIGUITY? BUT THE FINAL AUTHORITY TO SHOOT THE APCH RESTED WITH ME AND I CAN TELL YOU THAT I KNOW BETTER NOW.
Data retrieved from NASA's ASRS site as of August 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.