A House subcommittee is scheduled to hold next week the first open congressional hearing on unidentified aerial vehicles in more than half a century. The hearing comes after the release last June of a report requested by Congress on "unidentified aerial phenomena." The nine-page "Preliminary Assessment" from the Office of the Director of National Intelligence focused on 144 incidents dating back to 2004 and was able to explain only one. The report delivered to Congress last June was done by the intelligence community along with the Pentagon's Unidentified Aerial Phenomenon Task Force, which the Pentagon replaced in November with a new office, the Airborne Object Identification and Management Synchronization Group. Last December, Senator Kirsten Gillibrand ... and Representative Ruben Gallego ... succeeded with bipartisan support in inserting an amendment into the annual National Defense Authorization Act that directs that the Pentagon work with the intelligence community on the issue and make public reports about its findings. The amendment expanded the scope of the research beyond what the Pentagon group was already conducting. Congress has not held any open hearings on U.F.O.s since the Air Force closed a public investigation known as Project Blue Book in early 1970. In 1966, Gerald R. Ford ... organized a hearing in response to reports of U.F.O.s by over 40 people, including 12 policemen. The Air Force explained them away as "swamp gas," which Mr. Ford said was "flippant."