Narrative:

First officer was flying. WX was VFR with LLWS advisories in effect as there had been previous thunderstorm activity in the area. On final approach to runway 16 in den, the approach was very normal (flaps 30 degrees, reference speed 136 KIAS, target speed 141 KIAS), when a B737 in front of us reported a 20 KT loss at 100 ft over the runway. I told xx to make our target speed 150 KIAS, then upped it to 155 KIAS -- about 2 mi out. Aircraft was on profile and stabilized. As we approached the threshold, the airspeed increased to approximately 170 KTS. Then, at the 50 ft callout, the aircraft seemed to just drop, consequently, landing much harder than anticipated. At the time of touchdown, the windshear alert system activated in the cockpit. After touchdown, I immediately grabbed the controls to keep the aircraft on the ground and on the runway. 3 flight attendants and 2 customers were injured and escorted to the hospital for a check-up. Because some panels came down in the cabin, maintenance did a 2 hour inspection and found the aircraft to be airworthy. Ferried aircraft to chicago. Supplemental information from acn 440710: I hand flew the approach. It was smooth and stabilized. As we approached the threshold, I disconnected the autothrottles, and at the moment I did so, the airplane was on speed and on profile. At the GPWS 50 ft call, just as I was beginning the flare and bringing the power back and as I was transitioning my visual attention down the runway, I perceived that the headwind component was increasing. I stabilized my pitch to avoid floating in the flare. Then it seemed like the headwind abruptly dissipated and the airplane dropped to the runway.

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Original NASA ASRS Text

Title: A B747-400 FO MAKES A HARD LNDG AT DEN, CO. PAX AND FLT ATTENDANT INJURIES.

Narrative: FO WAS FLYING. WX WAS VFR WITH LLWS ADVISORIES IN EFFECT AS THERE HAD BEEN PREVIOUS TSTM ACTIVITY IN THE AREA. ON FINAL APCH TO RWY 16 IN DEN, THE APCH WAS VERY NORMAL (FLAPS 30 DEGS, REF SPD 136 KIAS, TARGET SPD 141 KIAS), WHEN A B737 IN FRONT OF US RPTED A 20 KT LOSS AT 100 FT OVER THE RWY. I TOLD XX TO MAKE OUR TARGET SPD 150 KIAS, THEN UPPED IT TO 155 KIAS -- ABOUT 2 MI OUT. ACFT WAS ON PROFILE AND STABILIZED. AS WE APCHED THE THRESHOLD, THE AIRSPD INCREASED TO APPROX 170 KTS. THEN, AT THE 50 FT CALLOUT, THE ACFT SEEMED TO JUST DROP, CONSEQUENTLY, LNDG MUCH HARDER THAN ANTICIPATED. AT THE TIME OF TOUCHDOWN, THE WINDSHEAR ALERT SYS ACTIVATED IN THE COCKPIT. AFTER TOUCHDOWN, I IMMEDIATELY GRABBED THE CTLS TO KEEP THE ACFT ON THE GND AND ON THE RWY. 3 FLT ATTENDANTS AND 2 CUSTOMERS WERE INJURED AND ESCORTED TO THE HOSPITAL FOR A CHK-UP. BECAUSE SOME PANELS CAME DOWN IN THE CABIN, MAINT DID A 2 HR INSPECTION AND FOUND THE ACFT TO BE AIRWORTHY. FERRIED ACFT TO CHICAGO. SUPPLEMENTAL INFO FROM ACN 440710: I HAND FLEW THE APCH. IT WAS SMOOTH AND STABILIZED. AS WE APCHED THE THRESHOLD, I DISCONNECTED THE AUTOTHROTTLES, AND AT THE MOMENT I DID SO, THE AIRPLANE WAS ON SPD AND ON PROFILE. AT THE GPWS 50 FT CALL, JUST AS I WAS BEGINNING THE FLARE AND BRINGING THE PWR BACK AND AS I WAS TRANSITIONING MY VISUAL ATTN DOWN THE RWY, I PERCEIVED THAT THE HEADWIND COMPONENT WAS INCREASING. I STABILIZED MY PITCH TO AVOID FLOATING IN THE FLARE. THEN IT SEEMED LIKE THE HEADWIND ABRUPTLY DISSIPATED AND THE AIRPLANE DROPPED TO THE RWY.

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.