MLG ENCOUNTERS WAKE TURB ON LNDG. SCRAPED LNDG LIGHT AS TEMPORARILY LOST ACFT CTL.

Narrative

OUR ASSIGNED RWY WAS 4R AT EWR. ACFT WERE DEPARTING ON 4L (INBOARD). THERE WAS A DIRECT XWIND FROM THE NW AT ABOUT 10-15 KTS. AT ABOUT 5-6 MI ON FINAL TWR CLRED US TO LAND AND CAUTIONED WAKE TURB DUE TO HVY ACFT DEPARTING INBOARD RWY. AT 2-3 MI ON FINAL I NOTICED THE BEGINNING TKOF ROLL OF THE HVY. ALL WAS NORMAL ON LNDG UNTIL APPROX 50 FT WHEN THE ACFT BEGAN DRIFTING SLIGHTLY R OF CTRLINE. WHILE IN THE FLARE THE ACFT DROPPED SUDDENLY MAKING A FIRM LNDG AND AT ABOUT THE SAME TIME THE L WING DROPPED RAPIDLY WHICH CAUSED EVASIVE ACTION BY THE CAPT TO LEVEL WINGS. AFTER CLRING THE RWY; I ADVISED THE TWR WE ENCOUNTERED SIGNIFICANT TURB JUST PRIOR TO TOUCHDOWN. AT THIS POINT WE WERE UNAWARE THE LNDG LIGHT HAD MADE CONTACT WITH THE RWY. MAINT DID NOT CATCH THE SCRATCHED LIGHT ON THE EXTERIOR WALK-AROUND. IN ALL FAIRNESS; SINCE THE LIGHTS ON AN MLG EXTEND FROM THE WING END; THERE VERY EASILY MAY NOT HAVE BEEN ANYTHING TO SEE IF THE LIGHTS RETRACTED NORMALLY DURING TAXI-IN. OUR NEXT FLT TO CVG DEPARTED ON TIME AND WAS A NORMAL FLT. HOWEVER; AFTER ARRIVING AT THE GATE IN CVG; MAINT MADE US AWARE OF A SCRAPE ON BOTTOM OF LNDG LIGHT AND THE LIGHT WAS NOT FULLY RETRACTED. THE ONLY RECOMMENDATION I HAVE WOULD BE TO GIVE MORE SPACING BTWN DEPARTING HVY ACFT; AND ARRIVING ACFT WHEN XWINDS ACCELERATE THE WAKE TURB ACROSS THE PATH OF LNDG ACFT.