LSA PILOT REPORTS HARD LANDING CAUSING GEAR DAMAGE CAUSED BY WIND SHIFT.

Narrative

I DSNDED TO APPROX 2000 FT WHERE AIR WAS SMOOTHER AND WESTERLY WINDS WERE LIGHTER; BUT WAS FACED WITH THE PROSPECT OF XING RISING TERRAIN; WHICH WOULD REQUIRE ASCENDING TO 4500 FT MSL TO SAFELY FLY OVER APCHING HILLS. THEREFORE; I DECIDED TO LAND TO TALK WITH ANY LCL PLTS ABOUT THE WIND CONDITION AND ALSO TO USE THE RESTROOM. THERE WAS NO TFC AND THE WINDSOCK ON THE RWY 27 END OF THE SINGLE RWY; 9/27; INDICATED ABOUT 260 DEGS LESS THAN 10 KTS; AND BLOWING STEADILY. HOWEVER; UNICOM ADVISED THAT THE WIND WAS VARIABLE AND SUGGESTED A PWR-ON LNDG. BECAUSE OF LIGHT TURB ON SHORT FINAL ABOVE TREES; I MAINTAINED HIGHER PWR. OVER-THE-FENCE PWR WAS 4500 RPM (ABOUT 75%); DECREASED TO 3500 RPM OVER-THE-THRESHOLD; WHICH WAS ABOUT 15% HIGHER THAN USUAL FOR VARIABLE WIND CONDITIONS. I BROUGHT THE PWR BACK TO 3300 RPM; STILL HIGHER THAN USUAL BECAUSE OF THE VARIABLE WINDS ALONG THE TREE-LINED; PAVED 2900 FT RWY. AT ABOUT 1/3 DOWN THE RWY I VISUALLY PICKED OUT A GAR POINT. APPROX 1200-1250 FT DOWN THE RWY; IT WAS AS THOUGH I HAD RUN INTO A WALL; AND THE PLANE PANCAKED; FROM 3-4 FT HT; ONTO THE MIDDLE OF THE RWY. THE HARD LNDG WAS A COMPLETE SURPRISE BECAUSE I WAS CARRYING SUFFICIENT PWR TO COMPENSATE FOR ANY JUDGEMENT ERRORS AND TO CUSHION THE LNDG. ALL 3 LNDG GEAR WERE DAMAGED. I SHUT DOWN; AND HAND-PUSHED THE ACFT OFF THE RWY. THE ARPT MGR AND AN ARPT BOARD MEMBER HELPED ME TO PUT THE ACFT INTO A HANGAR. SUBSEQUENTLY I LEARNED THAT A STORM CELL HAD PASSED THROUGH THE ARPT ABOUT AN HR-AND-HALF EARLIER; WHICH WAS NOT RPTED TO ME DURING MY WX BRIEFING PRIOR TO LEAVING ZZZ1. WHETHER I HAD ENCOUNTERED WINDSHEAR OR MICRO-BURST; I DO NOT KNOW. ALSO; AN ARPT BOARD MEMBER LATER TOLD ME THAT HE HAD EXPERIENCED AN ALMOST IDENTICAL WINDSHEAR INCIDENT IN HIS TAIL DRAGGER AND THAT A BONANZA ALSO HAD HAD AN IDENTICAL EXPERIENCE IN A PREVIOUS YR. THERE HAD BEEN OTHER HARD LNDGS AS WELL IN THE PAST BUT NOT NECESSARILY DUE TO WINDSHEAR. HE ALSO SAID THAT THE WIND HAD BEEN ACTING DIFFERENTLY THIS YR AS COMPARED TO PREVIOUS YRS. TO BECOME FAMILIAR WITH THE ACFT; AND PRIOR TO SETTING OUT ON THIS TRIP; I HAD PRACTICED XWIND AND VARIABLE WIND TKOFS AND LNDGS WITH AND WITHOUT AN INSTRUCTOR. THE PRACTICE ARPT ALSO HAS A SINGLE RWY; 9/27; EXCEPT THAT IT IS A GRASS STRIP; TREE-LINED WITH TREES ON APCH; ABOUT THE SAME WIDTH; AND WITH AN OPEN AREA IN APPROX THE SAME POS AS IN THE INCIDENT ARPT. EVERY PLT I HAVE DESCRIBED THE INCIDENT TO OPINED THAT THE INCIDENT; AND ACFT DAMAGE; PROBABLY COULD NOT HAVE BEEN AVOIDED.