Chief Designer and Test Pilot for Roy Halladay's Plane Died Flying One in May

John Murray Karkow, the chief designer and test pilot for the ICON A5 plane Roy Halladay fatally crashed Tuesday, died while flying the aircraft in California in May.

On Wednesday, Andrew Dalton of the Associated Press reported the National Transportation Safety Board ruled the 55-year-old Karkow's death was the result of "pilot error." The NTSB is now set to investigate the details leading to the longtime MLB pitcher's crash in the Gulf of Mexico.

An ICON A5 pilot and passenger were also injured during a hard landing in April in Florida, according to the AP. The pilot later told investigators the aircraft "descended faster than he expected."

No further information about Halladay's crash has been released.

Meanwhile, Flying magazine editor-in-chief Stephen Pope told Dalton there are ongoing concerns about how the A5 is being utilized over water.

"They still think that that's the way the airplane should be flown, and there are people in aviation who completely disagree with that," he said. "They think you should not have a low-time pilot flying low over water. That's a recipe for disaster."

Halladay, 40, was one of the best starting pitchers in baseball for an extended period of time. The Colorado native finished his career in 2013 with a 203-105 record and a 3.38 ERA across 416 MLB appearances, including 390 starts.

He won two Cy Young Awards, one in each league, and earned eight All-Star Game selections during a career that spanned 16 years with the Toronto Blue Jays and Philadelphia Phillies.