A PA28 PLT RPTS A FIRM LNDG THAT MAY HAVE RESULTED IN SOME ACFT DAMAGE.

Narrative

ON LNDG; I FLARED HIGH AND HAD A FIRM TOUCHDOWN. I REALIZED IT WAS FIRM; BUT DID NOT THINK IT WAS UNUSUALLY FIRM. THE ACFT TAXIED NORMALLY TO CUSTOMS AND THE FBO. PAX DEPLANED IN CLE; A WALKAROUND WAS COMPLETED; AND EVERYTHING WAS NOTED NORMAL. THE ACFT TAXIED TO RWY 24L FOR DEP; AND NORMAL TAXI WAS NOTED. DEPARTED CLE FOR BKL. NORMAL FLT; WITH A SMOOTH RIDE AND TOUCHDOWN AT BKL. NORMAL TAXI TO THE RAMP NOTED. ACFT WAS SECURED FOR OVERNIGHT. ABOUT 24 HRS LATER; I WAS NOTIFIED THAT THE ACFT APPEARED TO HAVE SOME STRESS DAMAGE TO THE L WING; CLOSE TO THE ROOT AT THE LEADING AND TRAILING EDGE. I NORMALLY DO NOT FLY INTO CLE IN SMALL ACFT. HOWEVER; I HAVE MADE HUNDREDS OF LNDGS AT CLE IN B737 ACFT. PERHAPS MY BRAIN MEMORY WAS USED TO THE PROFILE FLARE ATTITUDE AND ENVIRONMENT THAT I AM NORMALLY ACCUSTOMED TO IN THE B737'S; AND THIS CAUSED ME TO FLARE HIGH AND TOUCH DOWN FIRMLY IN THE PIPER ARCHER III. TO PREVENT THIS FROM OCCURRING AGAIN IN SMALL ACFT; I FEEL THAT I SHOULD MAKE AN ADDITIONAL AFFIRMATIVE MENTAL NOTE OF PROPER FLARE ATTITUDE PRIOR TO TOUCHDOWN. ALSO; I RECALL THE ACFT BEING PARKED IN THE SHADE ON THE L SIDE OF THE ACFT. PERHAPS DURING THE WALKAROUND THIS CIRCUMSTANCE CAUSED THE WING TO NOT SHOW ANY ABNORMALITIES.