CAPT OF AN LGT ACR ACFT STRUCK THE TAIL SKID DURING LNDG CAUSING DAMAGE TO THE SKID AND BOTTOM OF THE FUSELAGE TAIL AREA.

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AFTER I WAS ESTABLISHED ON COURSE INBOUND (ABOUT 5 NM OUTSIDE THE FAF); I RESET MY AIRSPD COMMAND BUG TO APCH SPD AND DISCONNECTED THE AUTOPLT. I CALLED FOR GEAR EXTENSION FOLLOWED BY LNDG FLAPS 28 DEGS AND THE 'BEFORE LNDG CHKLIST.' WE COMPLETED THE CHKLIST AND RECEIVED LNDG CLRNC. I CHOSE TO FLY THE FULL VOR APCH INSTEAD OF A VISUAL APCH UTILIZING THE VASI TO GET SOME PRACTICE. AT OUR COMPUTED VDP (1.5 NM FROM RWY) I DEPARTED THE MDA AND TRANSITIONED TO THE VASI GS. ALL PARAMETERS OF FLT WERE 'RIGHT ON;' BUT I HAD THIS FEELING OF 'BEING LOW.' I VISUALLY RECHKED MY SEAT POS AND FLAP CONFIGN AND FOUND THEM TO BE NORMAL. MY AIRSPD INDICATOR SHOWED ME ABOUT 2- 3 KTS ABOVE 'BUG' SPD AND THE PWR WAS NORMAL. AS WE CROSSED THE OVERRUN MY FO STATED '...YOU GOT A SINK GOING.' I XCHKED MY VSI AND NOTED A 700-900 FPM DSCNT. I ADDED PWR AND PULLED BACK SLIGHTLY ON THE YOKE IN AN ATTEMPT TO REDUCE THE DSCNT RATE. THROUGHOUT THE ENTIRE FINAL SEGMENT (FROM VDP TO TOUCHDOWN) I WAS ON THE VASI GLIDE PATH; AND WAS STABILIZED. WE TOUCHED DOWN FIRMLY ABOUT 1200-1500 FT AND COMPLETED THE ROLLOUT UNEVENTFULLY. I WAS STILL PUZZLED BY THE SINK AND FIRM TOUCHDOWN. IT WAS WHILE THE FO COMPLETED THE 'AFTER LNDG CHKLIST' THAT I NOTICED MY AIRSPD BUG WAS SET TO FLAPS 40 VREF OF 126 KTS; INSTEAD OF VREF FLAPS 28 OF 131 KTS PLUS 5 KTS OR 136 KTS. AFTER ARR WALK-AROUND INDICATED TAIL SKID COMPRESSION AND SOME SCRAPPINGS ON THE FUSELAGE AREA AROUND AND FORWARD OF THE TAIL SKID. EVEN THOUGH IN VISUAL CONDITIONS; FLYING THE VOR APCH AND THE RESULTING ALT STEP-DOWNS; LEVELOFF AT MDA; DSCNT AT VDP; AND RWY ALIGNMENT WITHIN 2 NM OF THE DID NOT ALLOW A FULLY STABILIZED APCH AND POSSIBLE EARLY RECOGNITION OF THE SPD REF ERROR. I ALSO FAILED TO INCLUDE IN MY XCHK THE FAST/SLOW INDICATION OF MY PRIMARY FLT DISPLAY OR ATTITUDE INDICATOR; RELYING FULLY ON MY AIRSPD INDICATOR AND REF BUG.