Accident Overview
On June 20, 2014, at approximately 1035 central standard time, a Grumman G-164 agricultural airplane, registration N455Y, sustained substantial damage after a forced landing following a loss of engine power near Anadarko, Oklahoma. The commercial-rated pilot, the sole occupant, sustained serious injuries. The flight was conducted under Federal Code of Regulations Part 137 for agricultural operations. Visual meteorological conditions prevailed, and no flight plan was filed. The local flight originated from a private agricultural airstrip near Anadarko at 1030.
Pilot Account
According to the pilot, the engine had been performing well on previous flights. He discovered an oil leak from the magneto gear seals of the Pratt & Whitney R-985 radial engine. On October 18th (as reported by the pilot), he contacted a repair station, Covington Aircraft, to arrange for a mechanic to replace the magneto seals. The mechanic arrived the next day, October 19th, and replaced the seals, also gapping the points before reinstalling the magnetos. After the work, the pilot started the engine and found the magneto check normal. He believed the airplane was fixed on the morning of the accident. He loaded 200 gallons of pesticide, warmed the engine for 30 minutes, and taxied to the departure runway. During the engine run-up, he performed a successful magneto check, and all engine gauges appeared normal.
During takeoff, the airplane lifted off normally and began climbing. While departing toward the northeast, the engine started losing power. As the pilot turned back toward the airstrip, the engine lost all power. When the airplane was approximately 100 feet above the ground, the pilot decided to land in a small open field below. He perceived an impending stall, pulled the throttle back fully, and pushed the stick forward. After flaring, the next thing he remembered was sliding backward with the top of the windscreen scooping up dirt.
Maintenance History
The most recent engine logbook entry was dated April 2, 2014, but did not show total engine time and recorded 0.0 hours since major overhaul (SMOH), with a test run, inspection, and return to service. The subsequent entry, dated March 2, 2014 (out of chronological order), stated that the engine was overhauled and returned to service. No logbook entries were found regarding the magneto seal replacement. However, separate documentation dated June 19, 2014, showed delivery and installation of a magneto drive seal kit, consistent with the pilot's report.
Investigation
The NTSB made repeated attempts to obtain additional information from the pilot and the pilot's representative, but these efforts were unsuccessful.