Narrative:

I was in command of an A300 operating from miami, fl, to huntsville, al. All our descent to land at huntsville airport was made under IMC and we requested deviations from our track due to adverse WX conditions. We received clearance to deviate and we were informed by the air traffic controller that in about 10 NM ahead, we would find better WX conditions. This information was in accordance with the conditions observed in our airborne WX radar. We were about 20 NM from huntsville airport maintaining 10000 ft and the autoplt was engaged. Initially, we found light to moderate turbulence and then heavy hail. Suddenly, we were affected by a strong descending vertical windshear and the aircraft started an uncommanded lost of altitude. I was acting as PF and my first reaction was to disconnect the altitude hold mode in order to have manual control of the pitch attitude with the column control and stop descend. Finally, I stopped the uncommanded descent at 7000 ft, but immediately we were now affected by a strong ascending vertical windshear and the aircraft started an uncommanded climb up to near 16000 ft. During this period, the air traffic controller called us a few times asking for our status and intentions, but we were not able to answer because our first priority was to control the aircraft. Once the aircraft was fully in control after the windshear procedure was completed, we answered the air traffic controller that our intentions in case of no improvement of WX conditions in hsv and bhm, we will proceed to memphis. ATC asked us to stop the climb and maintain 16000 ft while we already had the aircraft leveled off. By that time, the squall line was left south and we regained VMC conditions, so we decided to request clearance to continue the approach to huntsville airport. We were clear to descend and received vectors for the approach. Since we had stable WX conditions, I personally called ATC and gave details about the windshear conditions. During the rest of the approach and landing at huntsville airport, we did not find any further adverse WX conditions. It is important to inform you that the parameters of the engines were never exceeded. Also, during the uncommanded descent and climb of the aircraft, the mmo/vmo, stick shaker or initial buffet were never reached, found or felt. Finally, during the 3 hours xsit that the aircraft remained on the ground at huntsville airport, our mechanic on board, performed a thorough inspection according to the company maintenance manual. This inspection was performed with no findings.

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Original NASA ASRS Text

Title: AN A300 FLT CREW ENCOUNTERS WINDSHEAR RESULTING IN +6000 FT THROUGH -3000 FT ALTDEVS DURING APCH TO HSV.

Narrative: I WAS IN COMMAND OF AN A300 OPERATING FROM MIAMI, FL, TO HUNTSVILLE, AL. ALL OUR DSCNT TO LAND AT HUNTSVILLE ARPT WAS MADE UNDER IMC AND WE REQUESTED DEVS FROM OUR TRACK DUE TO ADVERSE WX CONDITIONS. WE RECEIVED CLRNC TO DEVIATE AND WE WERE INFORMED BY THE AIR TFC CTLR THAT IN ABOUT 10 NM AHEAD, WE WOULD FIND BETTER WX CONDITIONS. THIS INFO WAS IN ACCORDANCE WITH THE CONDITIONS OBSERVED IN OUR AIRBORNE WX RADAR. WE WERE ABOUT 20 NM FROM HUNTSVILLE ARPT MAINTAINING 10000 FT AND THE AUTOPLT WAS ENGAGED. INITIALLY, WE FOUND LIGHT TO MODERATE TURB AND THEN HVY HAIL. SUDDENLY, WE WERE AFFECTED BY A STRONG DSNDING VERT WINDSHEAR AND THE ACFT STARTED AN UNCOMMANDED LOST OF ALT. I WAS ACTING AS PF AND MY FIRST REACTION WAS TO DISCONNECT THE ALT HOLD MODE IN ORDER TO HAVE MANUAL CTL OF THE PITCH ATTITUDE WITH THE COLUMN CTL AND STOP DSND. FINALLY, I STOPPED THE UNCOMMANDED DSCNT AT 7000 FT, BUT IMMEDIATELY WE WERE NOW AFFECTED BY A STRONG ASCENDING VERT WINDSHEAR AND THE ACFT STARTED AN UNCOMMANDED CLB UP TO NEAR 16000 FT. DURING THIS PERIOD, THE AIR TFC CTLR CALLED US A FEW TIMES ASKING FOR OUR STATUS AND INTENTIONS, BUT WE WERE NOT ABLE TO ANSWER BECAUSE OUR FIRST PRIORITY WAS TO CTL THE ACFT. ONCE THE ACFT WAS FULLY IN CTL AFTER THE WINDSHEAR PROC WAS COMPLETED, WE ANSWERED THE AIR TFC CTLR THAT OUR INTENTIONS IN CASE OF NO IMPROVEMENT OF WX CONDITIONS IN HSV AND BHM, WE WILL PROCEED TO MEMPHIS. ATC ASKED US TO STOP THE CLB AND MAINTAIN 16000 FT WHILE WE ALREADY HAD THE ACFT LEVELED OFF. BY THAT TIME, THE SQUALL LINE WAS LEFT S AND WE REGAINED VMC CONDITIONS, SO WE DECIDED TO REQUEST CLRNC TO CONTINUE THE APCH TO HUNTSVILLE ARPT. WE WERE CLR TO DSND AND RECEIVED VECTORS FOR THE APCH. SINCE WE HAD STABLE WX CONDITIONS, I PERSONALLY CALLED ATC AND GAVE DETAILS ABOUT THE WINDSHEAR CONDITIONS. DURING THE REST OF THE APCH AND LNDG AT HUNTSVILLE ARPT, WE DID NOT FIND ANY FURTHER ADVERSE WX CONDITIONS. IT IS IMPORTANT TO INFORM YOU THAT THE PARAMETERS OF THE ENGS WERE NEVER EXCEEDED. ALSO, DURING THE UNCOMMANDED DSCNT AND CLB OF THE ACFT, THE MMO/VMO, STICK SHAKER OR INITIAL BUFFET WERE NEVER REACHED, FOUND OR FELT. FINALLY, DURING THE 3 HRS XSIT THAT THE ACFT REMAINED ON THE GND AT HUNTSVILLE ARPT, OUR MECH ON BOARD, PERFORMED A THOROUGH INSPECTION ACCORDING TO THE COMPANY MAINT MANUAL. THIS INSPECTION WAS PERFORMED WITH NO FINDINGS.

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.