It has been 19 months since Km and Trish Woliver and son Alex died when their Cessna 177 crashed in west Georgia.
In a report released Thursday, the National Transportation Safety Board blames the total engine failure on a rod end cap bolt that failed.
When the bolt came loose, the crank case split, losing its oil. That caused the engine to seize.
"The subsequent cause of the incident, it's not something that would be caught during routine maintenance. The only time it would have been noticed is at the time when the engine is overhauled," said pilot and SheltAir GM Mike Lerma.
Regulation requires engines be overhauled every 2000 to 3000 flight hours. The Woliver's engine was last overhauled in 2006.
As a pilot, Mike Lerma believes that the description of how Kim Wilover handled the engine lock up, including trying to make an emergency landing in a field, was the best possible option.
"Knowing there was no oil pressure and the engine was locked up, restarting wouldn't have been the wisest choice. I would be looking for a place to ditch the airplane and find the safest place to land," said Lerma.
Kim and Trish were killed instantly. Alex later died at an Atlanta hospital.