8h 24min, sep 11, 2001 y - Atta makes first transmission from AA11 to ground control
Description:
 Hijacker Mohammed Atta makes the first of two accidental transmissions from Flight 11 to ground control (apparently in an attempt to communicate with the plane’s cabin). 
Added to timeline:
Date:
8h 24min, sep 11, 2001 y
Now
 ~ 24 years ago