About six officers raised the jagged, 255-pound (11 5 -kilogramme) metal piece, which contains cranks, levers and bolts.
They took it over a three-story wall, lowered it into a courtyard, and carried it through a basement. Onlookers across the street took pictures as they loaded it onto a truck headed to a Brooklyn police facility.
The part was discovered a week ago, wedged in a narrow space between an apartment building and a mosque.
Authorities believe the rusted wing part is from one of the two hijacked airliners that brought down the trade center on September 11, 2001.
The 5-foot piece is a trailing edge flap support structure, police have said. Located close to the body of the plane, the part helps secure wing flaps that move in and out and aid in regulating plane speed.
Boeing officials told police the part came from one of its 767 airliners, but it isn't possible to determine which one. Both hijacked planes that struck the towers, American Airlines Flight 11 and United Airlines Flight 175, were Boeing 767s. American and United have had no comment.