CAMAS, Wash. -- The National Transportation & Safety Board released a preliminary report Friday on a Clark County plane crash that killed a well-known aviator and his son a week ago.

A witness reported observing the airplane depart the airport to the west and execute a 180-degree turn towards the airport, the report states.

The witness said the plane made a high-speed pass over the runway about 30 to 40 feet above ground level and pitched upwards abruptly near the end of the runway, then climbed out at a steep angle.

During the steep climb out, the airplane was observed performing an "aileron roll to the right." After the roll, the plane was in a level attitude when a slight movement was observed "as if it [the airplane] hit turbulence."

The airplane then descended below a tree line.

Benjamin Runyan, Sr., age 66, and Benjamin Runyan Jr., age 32, died in the crash.

Runyan, Sr. took off from Green Mountain airfield, a private airfield owned by Runyan himself, at about 4:30 p.m. The F.A.A. says the plane was bound for Klamath Falls.

The plane, a Russian "Yak 52" built in 1980, was in the air for about 30 seconds before it crashed, hitting trees about 2,500 feet off the end of the airstrip runway. A skid path could be seen leading up to the plane's wreckage.

Interactive Map: Crash location

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Location of fatal Clark. Co. plane crash

The Yakovlev 52 is popular at air shows and has a solid safety record, according to KGW Aviation reporter Jack Penning. A search by KGW of FAA records found no previous incidents with Runyan's plane.

Penning investigated the crash history of the Yak-52 and found twelve other fatal crashes since 2000, but no pattern to those crashes.