An initial report on the plane crash that killed four people near Birchwood Airport a week ago says the Cessna was making low turns on a survey flight just before it went down.
The National Transportation Safety Board on Wednesday morning released its preliminary findings on the crash roughly 2 miles southwest of Birchwood Airport.
Everyone on board -- pilot and former NTSB investigator George Kobelnyk, 64, as well as passengers Christian Bohrer, 20, Sarah Glaves, 36, and Kyle Braun, 27 -- died when the plane hit the ground and burst into flames at about 9 a.m. April 20.
Kobelnyk had been listed as a contact for Alaska Aviation Adventures, a firm that provided mountain flying as well as flightseeing and other trips. The NTSB report said the Cessna was registered to Kobelnyk and the flight was operated by a company called 70 North LLC, which Alaska Aviation Adventures' website said flew "in partnership" with the company.
"According to the operator's manager, the purpose of the flight was to do aerial surveying and photography over an area of land adjacent to the west edge of the airport property," investigators wrote.
Federal Aviation Administration radar tracking data from the morning of the crash showed the flight, which took off from the airport at about 8:40 a.m., making a series of turns south and then west of the airport at altitudes increasing from about 1,500 to 2,400 feet. The Cessna then headed northeast and southwest to make more turns, flying over the airport twice.
From a point southwest of the airport, the plane then entered a right turn, descending as low as 900 feet before climbing to 1,100 feet. The FAA radar track was lost after the plane headed southeast for about a mile.
"The last position from the radar data indicated that the airplane was about 800 feet (above mean sea level), with a ground speed of about 102 knots, and traveling on about a 126-degree track," investigators wrote.
When NTSB investigators reached the scene, they found that the plane had initially struck a 100-foot spruce tree. A debris field containing "small pieces of plexiglas, aluminum, a door frame assembly, and various landing gear components" extended nearly 500 feet west of the tree to the crash site. Firefighters said the plane had been found engulfed in flames, but the blaze was quickly extinguished by Chugiak fire crews.
"All of the airplane's major components were located at the main wreckage site," investigators wrote. "A post-crash fire incinerated a majority of the airplane's fuselage."
An 8 a.m. weather report from Birchwood Airport on the morning of the crash listed calm winds with visibility at 9 statute miles and overcast clouds at an altitude of 8,000 feet.
Wednesday's preliminary report is the first of three expected from the NTSB on the crash. A factual report containing more information about the crash will be followed by a board-approved report indicating its probable cause, in a sequence that typically takes about a year to complete.