I have changed my mind. A plane did hit the Pentagon but not a 757 - the key is the FEMA picture that shows the aircraft engine parts There all kinds of geometry problems with a Boeing 757 causing the Pentagon damage to the point where that just isn't possible.   The key to figuring out what hit the Pentagon is two pictures taken by FEMA on 13 Sep 2001.   The FEMA pictures show a Jet Engine part with a diameter of about 24" to 30".   After studying jet engines, it appears to be a high pressure compressor blade assembly.     https://www.fema.gov/media-library/assets/images/39382 https://commons.wikimedia.org/wiki/File:FEMA-_4415-_Photograph_by_Jocelyn_Augustino_taken_on_09-13-2001_in_Virginia.jpg If these pictures matched a part from a gigantic 757 engine, I would assume the photos have been doctored.  But they don't so it is unlikely the pics have been modified. It first appears to be a disc with little one or two inch fan blades with an outer ring.  But upon closer inspection, the blades extended through the ring but almost all of them have been sheared off.   Tomahawk - eliminated because diameter of entire missile is only two feet.   An AGM-84K SLAM-ER air-launched missile is even smaller - 13.5 Inches Maybe a drone: Global Hawk uses a Rolls Royce E3007 Turbo fan.  Diameter 40"  That initially sounds like a good bet.  But because it is a turbofan instead of a turbojet, the compressor blades are much smaller than the outer diameter of the engine, maybe 14 or 15 inches. Another possibility is a remotely operated A3 Skywarrior.  It uses a Pratt and Whitney J57/JTC3 turbojet engine.    This plane is much more reasonable than a 757 as far as the geometry to the damage to the Pentagon. Here's my best guess for the engine part - the compressor fan from the Pratt and Whitney J57 http://magaimg.net/img/67p4.jpg A Skywarrior airplane painted to look like a airliner would be consistent with eyewitness reports.   The size would be much more consistent with the damage, and the video evidence. http://magaimg.net/img/67p7.jpg Wingspan 72 feet Length 76 feet https://en.wikipedia.org/wiki/Douglas_A-3_Skywarrior