ROCKWOOD STRIP — The state medical examiner’s office has ruled that the death of a pilot whose plane crashed into Moosehead Lake Sunday was an accidental drowning.

An office spokeswoman released the cause of death of Telford M. Allen Jr., 64, on Tuesday morning.

Allen was founder of Telford Aviation Services and died around 11:30 a.m. Sunday when he tried to land his floatplane on the water near his home in Rockwood, officials said.

A passenger, Natalie Holmes-Moody, 61, was admitted and then released from Charles A. Dean Memorial Hospital in Greenville.

Allen, described by authorities as an experienced pilot, had been flying a Cessna 185 registered to Point Group LLC of Bangor. Maine State Police said Allen discovered “at the last moment” that the wheels had been down from the float mechanism, causing the plane to flip.

An investigation is being conducted by the National Transportation Safety Board.

A celebration of Allen’s life is scheduled during the Fly-In, Saturday, Sept. 11, at Telford Hangar in Greenville, according to his obituary.