B767 CAPT HAS TAIL STRIKE ON LNDG. MINOR DAMAGE TO TAIL SKID AND WATER DRAIN MAST.

Narrative

WE WERE CLRED FOR A VISUAL APCH AT 10 MI (TO RWY 30L STL). APCH WAS ROUTINE AND STABILIZED. REF SPD WAS 136 KTS. LNDG WT APPROX 282000 LBS. CAPT WAS FLYING. AT 500 FT; I CALLED AIRSPD AND DSCNT RATE (142 KTS 750 FPM); THEN 100 FT. THE COMPUTER CALLED 50 FT; 30 FT. RIGHT AFTER THE 30 FT CALL AT APPROX 20 FT THE CAPT PULLED THROTTLES TO IDLE. THE RWY LOOKED SLIGHTLY WET SO I WAS EXPECTING A GREASE JOB. WIND WAS 260 DEGS AT 9 KTS. WE FLOATED JUST A BIT; BUT ATTITUDE DID NOT LOOK ABNORMAL. TOUCHDOWN FELT NORMAL. IMMEDIATELY AFTER TOUCHDOWN; I LOOKED AT THE AIRSPD. I WAS JUST ABOVE 120 KTS. AS WE TURNED OFF; A FLT ATTENDANT RPTED A LOUD SCRAPING NOISE AFTER TOUCHDOWN THAT STOPPED WHEN WE WENT INTO REVERSE. WE TOLD HER WE WOULD CHK IT OUT AT THE GATE. TAXI WAS NORMAL TO PARKING. RPTED SCRAPING NOISE TO MECH AND ASKED HIM TO CHK IT OUT. CAPT WALKED BACK UNDER THE AIRPLANE TO CHK THE GEAR AND TAIL SKID AND DID NOT SEE ANYTHING UNUSUAL. LATER INSPECTION BY MECH REVEALED R GALLEY DRAIN MAST WAS DAMAGED; AS WELL AS THE TAIL SKID. CHKING 'TAIL STRIKE' ATTITUDE REVEALED IT WOULD OCCUR AT 8 DEGS PITCH AT 270000 LBS. A LNDG WHICH COMPRESSED THE STRUTS AND HIGHER WT COULD THEORETICALLY; AT LOWER PITCH ANGLE FOR TAIL CONTACT. PLTS FLYING B767-300 ACFT NEED TO BE (MADE) AWARE OF THE RELATIVELY LOW PITCH ATTITUDE FOR POSSIBLE TAIL STRIKE. PERHAPS THE REF SPD NEEDS TO BE RAISED 3-5 KTS.