investigators to conclude the plane crashed in the indian ocean. in june, a piece of the plane's wing, called a flapper-on, watched up on the coast of tanzania. analysis shows the wing flap had not been deployed before the crash, another sign no one was in control in those final moments. >> you would deploy the flaps by lowering it, slowing the plane down. >> reporter: bob hepp, a flight instructor, took us to demonstrate what the pilot should have done if they planned to successfully ditch the 777 in the indian ocean. we're going to do a landing now and deploy those flaps. >> we're going to put the flaps in, and this allows us to descend more steeply, slower and more steeply without picking up speed. >> reporter: the fact the flaps