B757-200 EXPERIENCES TAIL STRIKE ON LNDG AT TJSJ.

Narrative

AFTER BRIEFING THE CAPT AND SETTING UP THE AIRPLANE FOR AN AUTOLAND TO RWY 8 AT TJSJ; ATC CLEARED FLT FOR VISUAL APCH RWY 8. UPON INTERCEPTING THE LOC AND APPROX 2 NM FROM GS INTERCEPT; THE TJSJ TWR NOTIFIED US THAT AN MD11 WOULD BE TAKING OFF PRIOR TO OUR LNDG. WE CONFIGURED FOR LNDG AND RECEIVED NORMAL AUTOLAND INDICATIONS AT 1500 FT AGL. APPROX 1/2 - 3/4 NM FROM THE RWY THE ACFT DRIFTED TO THE R OF CTRLINE. I THEN DISCONNECTED THE AUTOPLT AND LINED UP THE ACFT FOR LNDG. FOLLOWING THIS; I BEGAN TO ARREST THE RATE OF DSCNT BTWN 30-40 FT AGL. AT THE 20 FT AUDIBLE CALL; I RETARDED THE THRUST LEVERS TOWARDS IDLE. UPON REACHING IDLE; THE THRUST LEVERS MOVED FORWARD. I THEN DISCONNECTED THE AUTOTHROTTLES BY CLICKING THE AUTOTHROTTLE DISCONNECT SWITCH ON THE THRUST LEVERS. I FELT WE HAD TOUCHED DOWN SMOOTHER THAN NORMAL BUT THE CAPT SAID 'WE'RE NOT DOWN YET.' I THEN NOTICED IT TOOK AN UNUSUAL AMOUNT OF PRESSURE TO KEEP THE NOSEWHEEL DOWN. THE CAPT BEGAN TO HELP ME PUSH DOWN ON THE NOSE/YOKE. WE TOUCHED DOWN WHEREUPON I ENGAGED THE THRUST LEVERS AND WHEEL BRAKES. WE CAME TO A STOP EXITING AT TXWY S9. WHILE GOING THROUGH THE AFTER LNDG CHKLIST; I NOTICED THE STABILIZER TRIM INDICATOR SHOWED FULL NOSE UP. SHORTLY THEREAFTER; ANOTHER ACFT RPTED TO THE TWR THAT THEY HAD SEEN SPARKS FROM OUR AFT LOWER FUSELAGE DURING LNDG. I THEN INFORMED THE CAPT WE MAY HAVE HAD A TAIL STRIKE. OUR POSTFLT INSPECTION CONFIRMED WE HAD A TAIL STRIKE ON LNDG. BECAUSE OF POSTFLT DEBRIEFS WITH MAINT AND FLT OPS/TIME CONSTRAINTS; I FORGOT TO ANNOTATE IN THE ACFT LOGBOOK THE FOLLOWING: TAIL STRIKE ON LNDG AND ACFT DRIFTED R OF CTRLINE ON AUTOPLT COUPLED APCH. I SUSPECT THE NOSE UP ACFT TRIM COUPLED WITH AUTO SPD BRAKE/SPOILER DEPLOYMENT CAUSED A HIGHER THAN NORMAL NOSE-UP ATTITUDE. ADDITIONALLY; THE MOMENTARY MOVEMENT OF THE THRUST LEVERS OUT OF IDLE BEFORE DISCONNECTED MAY HAVE CONTRIBUTED TO THE EXCESSIVE NOSE-UP ATTITUDE. SUPPLEMENTAL INFO FROM ACN 709047: AN UNUSUAL AMOUNT OF NOSE HIGH ATTITUDE OCCURRED THROUGHOUT THE FLARE PROCESS AND WAS ACCENTUATED WHEN THE SPD BRAKES DEPLOYED. AS THE CAPT; I ASSISTED THE FO BY USING FORWARD PRESSURE ON THE YOKE. THE ACFT THEN NOSED DOWNWARD SLIGHTLY AND BEGAN TRYING TO FLY AGAIN WITH THE SPD BRAKES DEPLOYED. A WDB TOOK OFF PREVIOUSLY AND WE PROBABLY ENCOUNTERED ITS JET WASH/WAKE TURB EFFECTS. FINALLY; AN AUDIT FOR CTR OF GRAVITY PURPOSES COULD HAVE BEEN PERFORMED; BUT WASN'T DUE TO THE FACT THAT THE ACFT WAS OFF-LOADED RIGHT AWAY UPON ARR AT THE GATE.