New Delhi, June 17 -- The B-52 that crashed during a test flight at Edwards Air Force Base in California was in the air a very short time before slamming into the ground about halfway down the runway.

All eight people aboard were killed in Monday's fiery crash of the Boeing B-52 Stratofortress, which was taking part in a test mission as part of a program to keep the oldest aircraft in the U.S. fleet flying for decades to come.

No cause has been determined. Officials at the base said it could take six months to complete the investigation.

The bomber took off shortly before noon on a clear day, heading southwest into the prevailing winds. It flew straight and crashed on the same 15,000-foot (4,572-meter) runway. The compact wreckage indi...