autopilot to 100 feet before leveling off again. >> he certainly was exploring the aircraft and its ability to go up or down and not stop him from descending it into the ground making sure nobody would see him. >> reporter: according to the new report the selected altitude decreased to 100 feet for three seconds. then increased to the maximum value of 49,000 feet less than two minutes later, the selected altitude was 100 feet until it stabilized at 25,000 feet. the flight never left its scheduled path so air traffic control didn't notice the altitude changes. >> unless the plane is equipped to stream the data and they decide to stream the data of the aircraft performance from the flight and someone's monitoring it they wouldn't have noticed. it was clear the pilot didn't notice. >> reporter: it appears to have a dry run for what he would do later on that morning on board the very same plane during the flight 9525.