The FLIGHT DECK Act directs the Federal Aviation Administration to create a voluntary training program allowing certified air traffic controllers to observe flight operations from an aircraft's flight deck during commercial flights. Eligible air traffic controllers can participate in at least one round-trip flight within the United States and its territories to better understand the complex requirements pilots and crew experience, with participants considered on-duty during the flights. Airlines, cargo operators, and general aviation companies may voluntarily participate in the program, though they are not required to displace off-duty pilots already occupying available flight deck seats. The FAA must establish regulations in consultation with airline pilot unions and air traffic controller representatives, and can impose additional security clearance and ticketing requirements to ensure safety. Within one year of the program's establishment, the FAA must report to Congress on participation rates, types of aircraft involved, barriers to participation, and recommendations for increasing engagement from both controllers and airlines.