FO OF A B737-400 STRUCK THE TAIL DURING LNDG RESULTING IN DAMAGE TO THE BOTTOM OF THE FUSELAGE FORWARD OF THE TAILSKID.

Narrative

SINCE I WAS THE PF AND SEATED IN THE R SEAT; THE CAPT EXPLAINED THE MANEUVER AND THAT HE WOULD CALL MY TURN TO BASE AND FINAL. UPON FINAL CONFIGN (GEAR AND 30 DEGS FLAPS); WE BEGAN OUR TURN AND DSCNT OUT OF 2000 FT. WE HAD A SLIGHT OVERSHOOT AND RED OVER PINK ON THE VASI; BOTH SITS WERE EASILY CORRECTED AND WERE ON GLIDE PATH AND CTRLINE. THE CAPT CALLED OUT SINKS AND AIRSPDS TO TOUCHDOWN. TOUCHDOWN WAS AT APPROX 1500 FT. I DID NOT NOTE ANY IRREGULARITIES WITH THE APCH. UPON TOUCHDOWN THE ACFT SKIPPED BUT DID NOT FEEL LIKE IT BECAME TOTALLY AIRBORNE; INSTEAD IT FELT AS THOUGH THE STRUTS WERE EXTENDED. THE CAPT SAID TO PULL BACK ON THE PWR AND MAINTAIN THE LNDG ATTITUDE TO PRECLUDE HITTING THE NOSE GEAR; AND WE SOON SETTLED BACK DOWN ON THE RWY. AFTER ROLLOUT WE TAXIED TO THE GATE AND COMPLETED ALL CHKLISTS PER NORMAL OPS. IT WAS NOT UNTIL THE FOLLOWING CREW PERFORMED THEIR PREFLT INSPECTION DID WE BECOME AWARE OF THE TAIL STRIKE. THE CAPT THEN VISUALLY INSPECTED THE DAMAGE AND DOCUMENTED THE INCIDENT IN THE ACFT MAINT LOG. WE DISCUSSED THE POSSIBLE CAUSE AND CAN ONLY SPECULATE THAT EXTRA PWR AT TOUCHDOWN CAUSED THE SKIP AND THEN SPOILER DEPLOYMENT THEN CAUSED THE RESETTLING. WE DO NOT FEEL AS THOUGH THE ACFT HAD EXCESSIVE PITCH OR SLOW SPD DURING THE SKIP AND WE WERE TOTALLY UNAWARE OF THE STRIKE.