Narrative:

During approach and landing, with winds reported as 220 degrees at 21 KTS gusting to 29 KTS and +-10 KTS, airspeed loss on final by B747. During landing in flare at 30 ft AGL, encountered windshear or loss of gust. Upwind wing dropped rapidly and #4 engine pod struck runway. Approach ATIS did not report windshear. ATIS, immediately after occurrence, was 220 degrees at 29 KTS gusting to 38 KTS, and windshear warning. Runway was closed 9 mins. Supplemental information from acn 433018: we got the 10 KT loss at about 500 ft AGL, touched down in a slight crab into the wind and got a slight bounce on first touchdown (no spoiler deployment). First officer held what he had (in terms of control position). Second touchdown was slightly right of centerline and spoilers deployed. Tower said something about 'smoke' and 'are you all right?' had no adverse cockpit or other indications, so we taxied to the ramp. Postflt inspection revealed a scrape approximately 3 ft long and 4-5 inches wide on #4 engine. First officer said it felt like the aircraft didn't respond normally in the flare, ie, large elevator 'pull' without expected pitch response (felt like the wind just quit to me). The next ATIS (after our landing) gave reports of a 20 KT airspeed loss on final. We never got a report of a 20 KT loss, just the 10 KT loss at 500 ft AGL by the preceding aircraft. I think maybe tower had some information about airspeed loss on final that they didn't pass along to us. Our company procedure calls for us to go around if airspeed loss (or reports of airspeed loss) is in excess of 15 KTS, and I'm sure the tower was aware of that.

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Original NASA ASRS Text

Title: AN ACR B747-200 FREIGHTER FLC HAD THE #4 ENG STRIKE THE RWY DURING A XWIND LNDG.

Narrative: DURING APCH AND LNDG, WITH WINDS RPTED AS 220 DEGS AT 21 KTS GUSTING TO 29 KTS AND +-10 KTS, AIRSPD LOSS ON FINAL BY B747. DURING LNDG IN FLARE AT 30 FT AGL, ENCOUNTERED WINDSHEAR OR LOSS OF GUST. UPWIND WING DROPPED RAPIDLY AND #4 ENG POD STRUCK RWY. APCH ATIS DID NOT RPT WINDSHEAR. ATIS, IMMEDIATELY AFTER OCCURRENCE, WAS 220 DEGS AT 29 KTS GUSTING TO 38 KTS, AND WINDSHEAR WARNING. RWY WAS CLOSED 9 MINS. SUPPLEMENTAL INFO FROM ACN 433018: WE GOT THE 10 KT LOSS AT ABOUT 500 FT AGL, TOUCHED DOWN IN A SLIGHT CRAB INTO THE WIND AND GOT A SLIGHT BOUNCE ON FIRST TOUCHDOWN (NO SPOILER DEPLOYMENT). FO HELD WHAT HE HAD (IN TERMS OF CTL POS). SECOND TOUCHDOWN WAS SLIGHTLY R OF CTRLINE AND SPOILERS DEPLOYED. TWR SAID SOMETHING ABOUT 'SMOKE' AND 'ARE YOU ALL RIGHT?' HAD NO ADVERSE COCKPIT OR OTHER INDICATIONS, SO WE TAXIED TO THE RAMP. POSTFLT INSPECTION REVEALED A SCRAPE APPROX 3 FT LONG AND 4-5 INCHES WIDE ON #4 ENG. FO SAID IT FELT LIKE THE ACFT DIDN'T RESPOND NORMALLY IN THE FLARE, IE, LARGE ELEVATOR 'PULL' WITHOUT EXPECTED PITCH RESPONSE (FELT LIKE THE WIND JUST QUIT TO ME). THE NEXT ATIS (AFTER OUR LNDG) GAVE RPTS OF A 20 KT AIRSPD LOSS ON FINAL. WE NEVER GOT A RPT OF A 20 KT LOSS, JUST THE 10 KT LOSS AT 500 FT AGL BY THE PRECEDING ACFT. I THINK MAYBE TWR HAD SOME INFO ABOUT AIRSPD LOSS ON FINAL THAT THEY DIDN'T PASS ALONG TO US. OUR COMPANY PROC CALLS FOR US TO GO AROUND IF AIRSPD LOSS (OR RPTS OF AIRSPD LOSS) IS IN EXCESS OF 15 KTS, AND I'M SURE THE TWR WAS AWARE OF THAT.

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.