A B737-800 ENCOUNTERS WINDSHEAR AT 50 FT AGL AND PERFORMS WHAT IS CONSIDERED A NORMAL RECOVERY AND TOUCHDOWN. AT THE GATE; MAINT FINDS A DAMAGED L TRAILING EDGE FLAP; SLC; UT.

Narrative

UPON TOUCHDOWN ON RWY 16L AT SLC; WE EXPERIENCED A VIOLENT SHIMMY REACTION IN THE ACFT. AS A RESPONSE; I STOWED THE GND SPOILERS AND SHIMMYING STOPPED. LATER IN ROLLOUT; DEPLOYED GND SPOILERS AND SHIMMYING DID NOT RECUR. DURATION OF SHAKING WAS 3-5 SECONDS. WHEN BLOCKED IN AT THE GATE AND ADVISED MAINT OF SHIMMYING; MAINT ADVISED US OF A BROKEN TRAILING EDGE FLAP ON THE L WING. SUPPLEMENTAL INFO FROM ACN 460337: CLRED FOR A VISUAL APCH AND TOLD TO FOLLOW AN ACFT ON A L BASE. SEPARATION WAS 4 MI. CONFIGURED FOR A 40 DEG FLAPS LNDG. ALL FLAP MOVEMENT SEEMED NORMAL. WE INCREASED OUR SEPARATION AND WERE CLRED TO LAND. AT APPROX 400 FT AGL; THE WINDS CHANGED FROM A 20 KT HEADWIND TO A 4 KT TAILWIND. AT APPROX 50 FT; THE ACFT DIPPED L WING LOW; WHICH I THOUGHT MAY HAVE BEEN FROM TURB FROM THE PRECEDING ACFT. THE WINGS WERE LEVELED AND THE FLARE AND TOUCHDOWN WERE NORMAL. NOT KNOWING THE CAUSE OF THE SHAKING OR SUSPECTING A FLAP PROB; THE FLAPS WERE RETRACTED DURING TAXI IN. AT THE GATE; THE MECH INFORMED US ABOUT DAMAGE TO THE L FLAP.