Image: United Airlines Flight 736 DC-7 collected debris

Description: Some of the debris collected from United Airlines Flight 736, a DC-7 which crashed on April 21, 1958 southwest of Las Vegas, Nevada.
Title: United Airlines Flight 736 DC-7 collected debris
Credit: http://aviation-safety.net/photos/displayphoto.php?id=19580421-0&vnr=1&kind=C The Aviation Safety Net page hosting the photograph indicates the photograph is in the public domain, per https://creativecommons.org/licenses/publicdomain/ Until this week the Aviation Safety Network incorrectly claimed the photograph was under copyright to the United States Civil Aeronautics Board, a former entity of the United States Government, but I sent them a letter disagreeing with that assessment. They agreed with my letter, and changed the license assertion on their hosting page, but have not yet removed the erroneous copyright watermark at the bottom of the photo. I have cropped out the watermark for this version to avoid further confusion.
Author: Employee of the United States Civil Aeronautics Board (CAB)
Usage Terms: Public domain
License: Public domain
Attribution Required?: No