The National Transportation Safety Board on Friday released its preliminary report on the fatal airplane crash that took place on April 24 near John Essex High School.

According to the preliminary report, the experimental plane containing only pilot Mark E. Keeley, 61, of Forkland inadvertently took off while he was running high-speed ground tests along Runway 22.

“During the second high-speed test run, at a point that was more than halfway along the runway, the airplane became airborne,” the report said, “and it was observed to be moving erratically along all three axes,” indicating left-right, forward-rear and up-down height directions.

The report states that the plane appeared to partially stabilize and flew away from the airport on the runway heading.

“The airplane made one left turn and then at least two right turns in an apparent attempt to return to the airport,” the report states. “After the first right turn, witnesses heard the engine sputter, and they stated that the engine cut out after the second right turn.”

The airplane then dropped at a steep angle, crashing in a field adjacent to the JEHS football field, about 1.9 miles east-southeast of Runway 22 at about 1:37 p.m. CDT. Keeley was killed in the accident.

The report states that Keeley held a private pilot certificate with airplane single-engine and multi-engine land ratings. Keeley’s most recent Federal Aviation Administration third-class medical certificate was issued in June 2008, when he reported 1,200 total hours of flight experience. Keeley was also reported to hold an experimental repairman certificate issued on Feb. 25 of this year.

The airplane was an all-metal, single-piece low-wing monoplane with fixed landing gear and a converted Volkswagen engine of 1,915 cubic centimeters displacement. Documents indicate that Keeley and another person were the co-builders of the plane, begun in 1996 and completed at a later date by Keeley. The plane was first registered in February 2009.

The NTSB will issue its complete findings in a final report at a later date.