Glenn Smith left a lucrative job at a Dallas-area technology firm for an early retirement of restoring Soviet fighter jets and flying to exhibitions across the country.

He died Saturday when his nearly 30-year-old training plane nosedived during an air show in eastern Iowa and crashed into a field, authorities said. Spectators watched the 59-year-old Smith's plane erupt into flames, followed by a cloud of gray smoke. Nobody on the ground was hurt.

Smith had been flying in formation with other members of the HopperFlight team at the Quad-City Air Show in Davenport.

The National Transportation Safety Board is investigating the crash. Senior air safety investigator Aaron Sauer said Sunday that a preliminary report on the crash is expected within a week, but a final report will likely take several months.

He said inspectors would examine the few remaining pieces of the plane, as well as Smith's autopsy and toxicology reports.

Smith did not make a mayday call or suggest any sign of distress before the crash, according to Sauer and Randy Ball, a good friend of Smith's.

Ball said Smith was a meticulous flier who would map every step of a flight plan beforehand.

'They practiced the day before and everything went fine,' Ball said.

Smith was a longtime technology entrepreneur whose company was acquired by Tyler Technologies, a Dallas-based com.