"A small amount of floating debris was recovered and taken to Coast Guard Air Station Barbers Point, where it was examined by NTSB investigators," the NTSB said in a statement.
The findings are expected to assist an investigation by a team that comprises experts from the NTSB, the Federal Aviation Administration, Boeing, engine manufacturer Pratt and Whitney, and several others.
The plane belonging to Rhoades Aviation (also known as Transair) crashed into the ocean immediately after takeoff near Honolulu. The cargo flight was bound for the Kahului island. Both members of the two-person flight crew sustained injuries, but were rescued by the coast guard.
The plane sank due to damage, its exact location on the ocean floor has yet to be determined.