B757 FLT CREW ENCOUNTERS WINDSHEAR ON APCH; EXECUTES MISSED APCH AND HAS AN ALTDEV AND EXCEEDS FLAPS ONE IAS LIMIT SPD.

Narrative

THE WX CONDITIONS WERE VERY CHALLENGING AND RAPIDLY CHANGING; AS BANDS OF PRECIP MOVED QUICKLY OVER THE FIELD. THE CEILING AND VISIBILITY WERE VARYING SIGNIFICANTLY OVER A VERY SHORT PERIOD OF TIME. ALTHOUGH WE BOTH COMPLETELY REVIEWED THE APCH PLATE FOR THE INTENDED APCH; I DID NOT ENSURE A THOROUGH APCH BRIEFING COMPLETELY COVERING ALL THE POSSIBLE EVENTUAL OUTCOMES OF AN APCH UNDER THESE DIFFICULT WX CONDITIONS. DURING THE FIRST APCH WE ENCOUNTERED A SIGNIFICANT AIRSPD GAIN AFTER INTERCEPTING THE LOC; BUT BEFORE FINAL CONFIGN. AT ABOUT 500 FT AGL; WE RECEIVED A VERY BRIEF WINDSHEAR ALERT AND DISCONTINUED THE APCH. THAT GAR SEEMED RELATIVELY UNEVENTFUL. THE SECOND APCH WAS COMMENCED WITH A 4000 FT RVR RPTED. ANOTHER ACFT WAS ABOUT 3 MI AHEAD ON THE APCH. THE OTHER ACFT DISCONTINUED THE APCH NEAR THE 'DA' AND RPTED MODERATE PRECIP ON FINAL WITH THE RWY NOT IN SIGHT AT 'DA.' WE ELECTED TO DISCONTINUE OUR APCH AT ABOUT 1000 FT AGL. THE TWR DIRECTED A TURN TO 180 DEGS AND CLB TO 3000 FT. AS THE FO WAS TURNING AND CLBING; THE FO UNDERSTOOD THE CLRNC TO BE FOR A CLB TO 4000 FT. I SET 3000 FT IN THE MCP. AS WE CLBED THROUGH 3000 FT; THE ALT ALERT ACTIVATED. I STARTED TO PUSH FORWARD ON THE YOKE; MISSED THE FO'S CALL FOR FLAPS UP AND DISCUSSED THE CLRED ALT WITH THE FO. BY THE TIME WE ARRESTED THE CLB; WE WERE APCHING 4000 FT. IT WAS AT THAT TIME THAT I SAW THE AIRSPD INCREASING; TRIED TO PULL THE PWR OFF QUICKLY ENOUGH TO AVOID THE FLAP 1 LIMIT SPD. THE ATTEMPT WAS UNSUCCESSFUL. AS WE GOT THE FLAPS/SLATS RETRACTED AND THE ACFT SLOWED; I CHKED IN WITH TRACON WITH OUR ALT. THEY DID NOT SEEM TO BE CONCERNED WITH OUR ALT. I AM REASONABLY CONFIDENT THAT OUR TWR ASSIGNED ALT WAS 3000 FT AND THAT THE FO HAD MISTAKEN THE ASSIGNED ALT AS 4000 FT. THE THIRD APCH WAS UNEVENTFUL.