A 90-year-old pilot’s death in a small plane crash in 2017 was likely caused by his decision to allow his large dog to fly in the passenger’s seat, the National Transportation Safety Board (NTSB) determined in a report released Monday.

Jerry Naylor, a former commercial pilot who was flying the single-engine airplane, crashed into a cornfield, 50 yards away from the runway at Monticello Regional Airport in Iowa.

While the late pilot’s son said his father routinely flew with his 70-pound dog, NTSB officials report that Naylor's loss of control of the plane was caused by the “dog's likely contact with the flight controls during landing.” Officials say Naylor died from “multiple blunt-force injuries sustained during the accident.”

The NTSB found no evidence of mechanical malfunctions or failures in the small plane, which led them to zero in on the dog as the cause of the crash.

The dog, whose name and breed were not identified by the NTSB, survived. A witness at Monticello Airport saw the dog running out of the cornfield after the crash.

“First responders were able to catch the dog, who was treated for minor injuries by a local veterinarian,” the NTSB said.