Accident Overview
On January 17, 2019, at about 1650 central standard time, a Beech A-36 airplane, registration N2021T, was destroyed when it impacted terrain in Fredericksburg, Texas. The pilot sustained fatal injuries. The flight was operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
Flight and Communications
The airplane was flying from Bulverde Airpark in San Antonio, Texas, to Gillespie County Airport (T82) in Fredericksburg. Another pilot reported hearing a Bonanza (Beech A-36) pilot announce a "mayday" call on the common traffic advisory frequency, indicating the airplane's engine was on fire.
Aircraft and Maintenance History
The pilot purchased the airplane in October 2018 and logged 5.0 flight hours that month. Records showed the engine was last overhauled on December 9, 2010, at a tachometer time of 1,585.1 hours. At the time of the October 2018 annual inspection, the engine had accumulated 412.2 hours since overhaul. The airplane was equipped with a Lycoming TIO-540 reciprocating engine and a Hartzell propeller, installed under Supplemental Type Certificate SA762NW (Machen Inc. engine and propeller conversion).
Impact and Wreckage
The initial impact point was at the edge of a field about 1 mile north of T82. The airplane then struck a slightly elevated country road and came to rest upright. A post-crash fire consumed a majority of the airframe. The wreckage was initially recovered to an impound yard and later moved to an aircraft salvage facility near Lancaster, Texas.
Postaccident Examination
An examination conducted by the National Transportation Safety Board (NTSB) Investigator-in-Charge, along with technical representatives from the engine and airframe manufacturers, revealed fire damage to the engine. Manual rotation was limited due to internal binding. Disassembly of the engine disclosed a broken camshaft and crankshaft. The broken components, along with cylinders and pistons, were sent to the NTSB Material Laboratory.
Laboratory Findings
The laboratory examination identified crack arrest marks in the crankshaft, consistent with fatigue. The fatigue initiated in the fillet radius at the forward end of the number 6 connecting rod journal. Multiple crack origins and prominent crack arrest lines indicated relatively high stress associated with crack initiation.