Investigation Reveals Disturbing Details of Recent Plane Crashes.

The National Transportation Safety Board (NTSB) has released a preliminary report on the Cessna Citation crash that occurred earlier this month. The report reveals that the pilot, Jeff Hefner, suddenly lost contact with air traffic controllers after reading back a series of instructions. The business jet then flew for almost two hours before crashing in the Virginia mountains. The crash was linked to a boom heard across the Washington region caused by military jets racing faster than the speed of sound to catch the Citation. The report represents facts NTSB investigators have gathered in their investigation so far, but adds few new details to what is already publicly known about the crash.