Narrative:

Climbing out on a ferry flight we started to hear random banging sounds from what sounded like under our feet in the east&east compartment. The sounds moved about and caused us concern. We elected not to continue and informed center of our need to return to ZZZ. We did not declare an emergency; however; center said they were treating us as an emergency aircraft. We completed all checklists and landed normally. At the gate; a 1 ft by 1 ft by 2 ft metal box containing aircraft parts was found not secured in the forward cargo hold.

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Original NASA ASRS Text

Title: AN ACR FLT CREW REPORTS HEARING BANGING NOISES UNDER THEIR FEET THAT TURNED OUT TO BE AN UNSECURED BOX OF ACFT PARTS IN THE FWD CARGO HOLD.

Narrative: CLBING OUT ON A FERRY FLT WE STARTED TO HEAR RANDOM BANGING SOUNDS FROM WHAT SOUNDED LIKE UNDER OUR FEET IN THE E&E COMPARTMENT. THE SOUNDS MOVED ABOUT AND CAUSED US CONCERN. WE ELECTED NOT TO CONTINUE AND INFORMED CTR OF OUR NEED TO RETURN TO ZZZ. WE DID NOT DECLARE AN EMER; HOWEVER; CTR SAID THEY WERE TREATING US AS AN EMER ACFT. WE COMPLETED ALL CHKLISTS AND LANDED NORMALLY. AT THE GATE; A 1 FT BY 1 FT BY 2 FT METAL BOX CONTAINING ACFT PARTS WAS FOUND NOT SECURED IN THE FORWARD CARGO HOLD.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.