E145 SUFFERS LOUD BANGING NOISES AGAINST FUSELAGE AFTER TKOF. RETURNS FOR EMERGENCY LANDING.

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ON INITIAL CLBOUT AFTER GEAR WAS RETRACTED THERE WAS A LOUD CLAPPING/THUD SOUND ALONG THE L SIDE OF THE NOSE LNDG GEAR. I THOUGHT THAT THE GND CREW HAD FORGOTTEN TO CLOSE THE COM DOOR. CAPT STATED THAT DOESN'T SOUND LIKE THIS WHEN THAT IS LEFT OPEN. WE BELIEVE THAT WE MAY HAVE CAUGHT A PIECE OF FOD UPON ROTATION SINCE THE WIND WAS VERY STRONG AND GUSTY. THAT UPON ROTATION AND THE GEAR WAS BEING RETRACTED IT WAS HANGING OUT AND FLAPPING AGAINST THE ACFT AND AS THE ACFT WOULD SPD UP THE LOUDER AND MORE FREQUENT THE SOUND WOULD BECOME. DEP WAS CONTACTED WHEN ADVISED TO DO SO BY ZZZ TWR. UPON CONTACT WE WERE GIVEN DIRECT XYZ WHEN ABLE AND WE ADVISED THAT WE WOULD NEED TO BE VECTORED BACK TO THE ARPT BECAUSE OF WHAT WE WERE HEARING. ATC GAVE US VECTORS TO FLY AROUND TO FIGURE OUT WHAT EXACTLY WE NEEDED TO DO. I TOOK THE CTLS AND MONITORED THE ACFT WHILE THE CAPT CONTACTED MAINT TO FIGURE OUT WHAT THE PROB COULD HAVE BEEN. DEP ADVISED THAT WE COULD POSSIBLY DO A FLY-BY TO HAVE THE TWR INSPECT THE ACFT. I HAD ADVISED DEP CTL THAT IT WOULD BE BETTER IF WE WOULD BE ABLE TO DO A FLY-BY ON RWY 11 TO STAY THE WAY OUT OF THE REST OF LNDG TFC AND ALSO BECAUSE WE NEEDED THE L SIDE OF THE ACFT TO BE INSPECTED. THE FLT ATTENDANT HEARD THE SAME NOISE AS US AND WE HAD INFORMED HER AND THE PAX THAT WE WOULD BE DOING A FLY-BY OF THE TWR AND THEN FOLLOWED BY A LNDG AND NOT TO BE ALARMED. WHEN THE LNDG GEAR WAS EXTENDED AGAIN WE DIDN'T HEAR THE NOISE. THE FLY-BY WAS CONDUCTED FOLLOWED BY A GAR AND THEN WE ENTERED A L XWIND FOR A LNDG ON RWY 12R. AS WE WERE TURNING INTO THE XWIND FOR A VISUAL LNDG ON RWY 12R AN EMER WAS DECLARED AND WE WERE GOING TO BE OVERWT. THE CFR TRUCKS WERE BROUGHT OUT AND FOLLOWED US DOWN THE RWY UPON LNDG AS WELL AS BACK TO THE GATE. THE OVERWT LNDG WAS DONE AT ABOUT 250-300 FPM UPON TOUCHDOWN IN THE GUSTY WINDS WE WERE ENCOUNTERING. ALL ENDED WELL AND MAINT MET US AT THE GATE AND WE SWITCHED ACFT TO CONTINUE TO ZZZ1. THE ONLY SUGGESTION I COULD GIVE WOULD BE IF YOU SEE FOD AROUND; PLEASE PICK IT UP. YOU MAY NEVER KNOW WHAT EXACTLY THAT PIECE OF FOD CAN DO.