Event Overview
On August 17, 2012, at about 1345 mountain daylight time, a Beech A36 (registration N262EA) experienced an engine malfunction and executed a forced landing in a wheat field near Ruleton, Kansas. The pilot and two passengers were not injured. The airplane was substantially damaged, including a broken right wing rear spar. The flight originated from Goodland, Kansas (KGLD) at approximately 1330, with an intended destination of Fort Morgan, Colorado (KFMM). Visual meteorological conditions prevailed, and no flight plan was filed.
Pilot Actions and Observations
According to the pilot's accident report, before departure from Sidney, Nebraska, the engine crankcase contained 9 quarts of oil (12 quarts maximum capacity). The pilot arrived at KGLD about 1230; it is not stated whether he checked the oil before departing. Shortly after leveling at a cruising altitude of 8,500 feet, the pilot heard the engine RPM increase and noted the tachometer at the top of the gauge. He reduced power to 2,500 RPM but could not restore thrust or maintain altitude. He extended the landing gear and landed in a wheat field near County Roads 74 and 9, about 12 miles northwest of KGLD.
Post-Accident Examination
FAA inspectors at the accident site found the turbocharger controller covered with oil. After recovery to a hangar, 5 quarts of oil were drained from the crankcase. On September 27, 2012, the turbocharger controller was examined at Beegles Aircraft Service in Greeley, Colorado. Oil covered the controller piping. Shop air (35-95 psi) introduced via the oil pressure inlet hose caused the wastegate control valve to open and close normally. A soapy solution applied to fittings revealed air bubbles at the elbow fitting of the outlet hose going to the wastegate controller. The outlet fitting was loosened and removed; the O-ring was discovered flattened. After reseating the O-ring and re-torquing the elbow fitting, no further bubbles were observed with shop air and soapy solution.
Maintenance History
Examination of maintenance records indicated the last annual/100-hour inspection occurred on October 10, 2011, at which time the engine, turbocharger, controller, and wastegate were overhauled. These components were reinstalled on November 12, 2011, at a Hobbs meter time of 1,907.6 hours. Routine oil changes followed on February 1, 2012 (1,909.8 hours), April 26, 2012 (1,962.8 hours), and June 12, 2012 (38.5 hours after the Hobbs meter was changed on April 26).