Accident Overview
On July 8, 2017, at approximately 1050 central daylight time, a Beech VA airplane experienced a loss of engine power and executed a forced landing near Walters, Oklahoma. The airplane sustained substantial damage to the firewall and lower fuselage. The airline transport pilot and one passenger sustained minor injuries.
Flight Details
The flight originated at 1040 from Kickapoo Downtown Airport (CWC) in Wichita Falls, Texas, and was en route to Lawton, Oklahoma. Visual meteorological conditions prevailed, and no flight plan was filed. The airplane was registered to Gas Corporation of America of Wichita Falls, Texas, and was operated by the pilot under Title 14 Code of Federal Regulations Part 91.
Engine Failure and Forced Landing
The pilot reported that approximately 10 minutes after departure, the oil pressure dropped to zero and the engine failed. He executed a forced landing to a soft farm field about one mile south of Walters Airport (OK12). After landing, the pilot and passenger exited the airplane with minor injuries.
Examination Findings
Review of the airplane's maintenance records revealed that the vacuum pump had been replaced on July 7, 2017, the day before the accident. Subsequent disassembly and examination of the engine found that an improper gasket (P/N-21051) had been installed on the vacuum pump. This gasket is normally used for carburetor installation and did not completely cover the high-pressure oil orifice on the vacuum pump mounting fixture. The correct gasket for the vacuum pump is PN-MS9134-01. Examination of the engine revealed that three connecting rods showed thermal and impact damage, and three rod journals were dry with thermal discoloration.