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Automated surface observing system unreliable.
| Attributes | |
| ACN | 278507 |
| Time | |
| Date | 199407 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : mcn |
| State Reference | GA |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : dtw |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : local |
| Qualification | controller : radar |
| Experience | controller radar : 4 |
| ASRS Report | 278507 |
| Events | |
| Anomaly | other anomaly other |
| Independent Detector | other controllera |
| Resolutory Action | none taken : unable |
| Consequence | faa : investigated |
| Supplementary | |
| Primary Problem | Weather |
| Air Traffic Incident | other |
Narrative:
A fast moving thunderstorm was moving through the macon airport. The ASOS seemed to lag about 10 mins behind actual conditions at the airport. At XX00 the ASOS transmitted a special observation of 10 scattered M22 broken 30 overcast 1/2 r-f, however the prevailing visibility from the tower was 7 mi. At XX28 air carrier X reported the airport in sight 10 mi north of the airport. The ASOS transmitted a special observation at XX29 of 10 scattered M22 broken 30 overcast 3/4 4-F. Observation at this particular time was incorrect. The WX about XX15Z might have had a visibility of 3/4 r-f but not at XX29Z. Air carrier X had to be vectored 20 mi out of its way through scattered thunderstorms for the ILS approach. It seems that the ASOS has a 13-15 lag behind actual WX conditions. The NWS is unable to augment the visibility to show true conditions. This ASOS is unsafe due to this lag of the WX conditions. Callback conversation with reporter revealed the following information: reporter stated the automated surface observing system does not report the current WX. Although the system is supposed to be updating the WX it will not augment itself to changing conditions. NWS observers won't input the current WX when the tower asks for a special. NWS observers will be transferred when FAA accepts the system. Region has stopped any further installation and acceptance of ASOS until problems can be worked out.
Original NASA ASRS Text
Title: AUTOMATED SURFACE OBSERVING SYS UNRELIABLE.
Narrative: A FAST MOVING TSTM WAS MOVING THROUGH THE MACON ARPT. THE ASOS SEEMED TO LAG ABOUT 10 MINS BEHIND ACTUAL CONDITIONS AT THE ARPT. AT XX00 THE ASOS XMITTED A SPECIAL OBSERVATION OF 10 SCATTERED M22 BROKEN 30 OVCST 1/2 R-F, HOWEVER THE PREVAILING VISIBILITY FROM THE TWR WAS 7 MI. AT XX28 ACR X RPTED THE ARPT IN SIGHT 10 MI N OF THE ARPT. THE ASOS XMITTED A SPECIAL OBSERVATION AT XX29 OF 10 SCATTERED M22 BROKEN 30 OVCST 3/4 4-F. OBSERVATION AT THIS PARTICULAR TIME WAS INCORRECT. THE WX ABOUT XX15Z MIGHT HAVE HAD A VISIBILITY OF 3/4 R-F BUT NOT AT XX29Z. ACR X HAD TO BE VECTORED 20 MI OUT OF ITS WAY THROUGH SCATTERED TSTMS FOR THE ILS APCH. IT SEEMS THAT THE ASOS HAS A 13-15 LAG BEHIND ACTUAL WX CONDITIONS. THE NWS IS UNABLE TO AUGMENT THE VISIBILITY TO SHOW TRUE CONDITIONS. THIS ASOS IS UNSAFE DUE TO THIS LAG OF THE WX CONDITIONS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THE AUTOMATED SURFACE OBSERVING SYS DOES NOT RPT THE CURRENT WX. ALTHOUGH THE SYS IS SUPPOSED TO BE UPDATING THE WX IT WILL NOT AUGMENT ITSELF TO CHANGING CONDITIONS. NWS OBSERVERS WON'T INPUT THE CURRENT WX WHEN THE TWR ASKS FOR A SPECIAL. NWS OBSERVERS WILL BE TRANSFERRED WHEN FAA ACCEPTS THE SYS. REGION HAS STOPPED ANY FURTHER INSTALLATION AND ACCEPTANCE OF ASOS UNTIL PROBS CAN BE WORKED OUT.
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.