Narrative:

While descending through 2500 ft AGL on a left downwind runway 14R, #2 for a visual approach behind a twin beech turning final, we encountered strong moderate turbulence. Fortunately the flight attendants had been signaled and were in the last phase of cabin landing preparation, but they had to use the handrails for stability to reach their seats (and voiced appreciation for this series 2000 feature afterward). An overhead storage door opened at some point, but the contents did not fall out. The turbulence was unrpted to us and came as a surprise. As the beech was touching down, we were approximately 4 mi on final when the tower reported winds 320 degrees at 9 KTS. Clearance was arranged to break off the approach and fly a right visual pattern to runway 32L. On base leg, it was apparent that our drift was toward the runway (ie, to northwest) and opposite the reported surface wind. The tower called out 'windshear alert' followed by field wind sensor data (a poor means of imparting relevant data) that did not seem too extreme, but preparations for a go around were discussed. Tower reported winds at 320 degrees at 15 KTS gusting to 20 (or 25) KTS. Passing approximately 1500 ft on final, the airspeed increased from approximately 140 KTS to 180 KTS and the go around was executed. As thrust was advanced, the amber 'windshear caution' flashed for approximately 5 seconds (it was very dim and barely noticeable). An air carrier B737 then flew the visual approach (with a condition update from us) and landed successfully. Our second approach again encountered a strong airspeed increase at 1500 ft AGL, but speed was easily stabilized and +/-5 KTS to a smooth touchdown. First officer was able to talk to the beech pilots later, and learned that they had lost airspeed just at touchdown. It would seem that, if we had continued for runway 14R a bit earlier, the possibility for a 30-40 KT loss of airspeed on short final is highly conceivable. The lack of accurate usable real- time WX information, coupled with the lack of predictive windshear warning, combined to put the airplane in a precarious situation that only the luck of a wind change report occurring 45 seconds prior to touchdown prevented.

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Original NASA ASRS Text

Title: DC9-30 ENCOUNTERED WINDSHEAR WHILE ON FINAL APCH RWY 14R. BROKE OFF APCH AND ENTERED R DOWNWIND FOR RWY 32L. WHILE ON FINAL RWY 32L, WINDSHEAR WAS ENCOUNTERED AGAIN AND ANOTHER GAR WAS PERFORMED. WINDSHEAR WAS ENCOUNTERED ON THE NEXT APCH BUT SPD WAS STABILIZED AND A SMOOTH LNDG ENSUED.

Narrative: WHILE DSNDING THROUGH 2500 FT AGL ON A L DOWNWIND RWY 14R, #2 FOR A VISUAL APCH BEHIND A TWIN BEECH TURNING FINAL, WE ENCOUNTERED STRONG MODERATE TURB. FORTUNATELY THE FLT ATTENDANTS HAD BEEN SIGNALED AND WERE IN THE LAST PHASE OF CABIN LNDG PREPARATION, BUT THEY HAD TO USE THE HANDRAILS FOR STABILITY TO REACH THEIR SEATS (AND VOICED APPRECIATION FOR THIS SERIES 2000 FEATURE AFTERWARD). AN OVERHEAD STORAGE DOOR OPENED AT SOME POINT, BUT THE CONTENTS DID NOT FALL OUT. THE TURB WAS UNRPTED TO US AND CAME AS A SURPRISE. AS THE BEECH WAS TOUCHING DOWN, WE WERE APPROX 4 MI ON FINAL WHEN THE TWR RPTED WINDS 320 DEGS AT 9 KTS. CLRNC WAS ARRANGED TO BREAK OFF THE APCH AND FLY A R VISUAL PATTERN TO RWY 32L. ON BASE LEG, IT WAS APPARENT THAT OUR DRIFT WAS TOWARD THE RWY (IE, TO NW) AND OPPOSITE THE RPTED SURFACE WIND. THE TWR CALLED OUT 'WINDSHEAR ALERT' FOLLOWED BY FIELD WIND SENSOR DATA (A POOR MEANS OF IMPARTING RELEVANT DATA) THAT DID NOT SEEM TOO EXTREME, BUT PREPARATIONS FOR A GAR WERE DISCUSSED. TWR RPTED WINDS AT 320 DEGS AT 15 KTS GUSTING TO 20 (OR 25) KTS. PASSING APPROX 1500 FT ON FINAL, THE AIRSPD INCREASED FROM APPROX 140 KTS TO 180 KTS AND THE GAR WAS EXECUTED. AS THRUST WAS ADVANCED, THE AMBER 'WINDSHEAR CAUTION' FLASHED FOR APPROX 5 SECONDS (IT WAS VERY DIM AND BARELY NOTICEABLE). AN ACR B737 THEN FLEW THE VISUAL APCH (WITH A CONDITION UPDATE FROM US) AND LANDED SUCCESSFULLY. OUR SECOND APCH AGAIN ENCOUNTERED A STRONG AIRSPD INCREASE AT 1500 FT AGL, BUT SPD WAS EASILY STABILIZED AND +/-5 KTS TO A SMOOTH TOUCHDOWN. FO WAS ABLE TO TALK TO THE BEECH PLTS LATER, AND LEARNED THAT THEY HAD LOST AIRSPD JUST AT TOUCHDOWN. IT WOULD SEEM THAT, IF WE HAD CONTINUED FOR RWY 14R A BIT EARLIER, THE POSSIBILITY FOR A 30-40 KT LOSS OF AIRSPD ON SHORT FINAL IS HIGHLY CONCEIVABLE. THE LACK OF ACCURATE USABLE REAL- TIME WX INFO, COUPLED WITH THE LACK OF PREDICTIVE WINDSHEAR WARNING, COMBINED TO PUT THE AIRPLANE IN A PRECARIOUS SIT THAT ONLY THE LUCK OF A WIND CHANGE RPT OCCURRING 45 SECONDS PRIOR TO TOUCHDOWN PREVENTED.

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.