The National Transportation Safety Board should have some results in five days as to what caused the Cessna to clip a PG&E power line and crash on Beech Street in East Palo Alto, said aviation accident inspector Joshua Cawthra. What will help, he added, is East Palo Alto's "shot spotter'' system, the city's high-tech sensors that detect gun shots. The noises from the plane's engine were detected on the system, and could help explain why the plane crashed moments after taking off in heavy fog for a trip to Southern California.

Cawthra did state today, however, that Bourn made "zero distress calls'' from the air, and had said his last words to radio control from the ground.