Accident Overview
On June 30, 2018, at approximately 1155 central daylight time, a Cessna 337F multiengine centerline thrust airplane, registered as N107BL, sustained substantial damage when it struck trees and a fence during a forced landing about one mile southeast of Vinland Valley Aerodrome (K64) in Baldwin City, Kansas. The commercial pilot, who also held an airframe and powerplant (A&P) mechanic certificate, was not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a local personal flight, and visual meteorological conditions prevailed. No flight plan had been filed.
Sequence of Events
According to the pilot, after takeoff and climb to 3,500 feet, he shut down the rear engine and feathered the propeller to practice single-engine operations. Following some air work, he attempted to unfeather the propeller and restart the rear engine but was unsuccessful. The pilot then returned to the airport and initiated a single-engine landing approach.
During the approach, the pilot noticed that he had lost the full flap down setting and determined that a full stop landing on the grass runway would be close. He reduced flaps to 10°, but the flap setting then "relaxed," and he concluded there was insufficient altitude to retract the landing gear. The pilot maneuvered to avoid houses and carried out a forced landing in a crosswind. Full power and full flaps were maintained until touchdown. The airplane struck small trees, shrubs, and a fence, resulting in a bent left wing and a buckled fuselage.
Post-Accident Examination
Examination of the rear engine propeller system revealed that the remote hydraulic accumulator, which assists in unfeathering the propeller and is normally serviced to 120 psi, had been found slightly low during an annual inspection conducted about 4 flight hours prior to the accident. Post-accident measurement showed the pressure was 85 psi, and it was most likely that a nitrogen leakage had developed during those 4 hours. Additionally, the flap switch was found not to be holding its position; the reason for this anomaly could not be determined.
Aircraft and Operator Information
The airplane, a Cessna 337F, was registered to and operated by Vinland Aerodrome of Baldwin City, Kansas. The commercial pilot, also an A&P mechanic, was the sole occupant. The aircraft was substantially damaged.
Meteorological Information
Visual meteorological conditions were present at the time of the accident. No other weather details were provided in the source.