10:00 a.m. September 11, 2001: Flight 93 Transponder Gives Brief Signal
The transponder for Flight 93 briefly turns back on. The plane is at 7,000 feet. The transponder stays on until about 10:03 a.m. It is unclear why the transponder signal briefly returns. [Guardian, 10/17/2001; MSNBC, 9/11/2002]