Accident Details
On July 3, 2017, at about 2006 mountain daylight time, a single-engine Beech A36 airplane (registration N24LF) experienced a loss of engine power during the initial climb after takeoff from El Paso International Airport (ELP), El Paso, Texas. The commercial pilot and passenger were not injured. The airplane sustained substantial damage. The aircraft was registered to and operated by GTA Air, Inc., under 14 Code of Federal Regulations Part 135. Visual meteorological conditions prevailed, and a Federal Aviation Administration visual flight rules flight plan had been filed. The non-scheduled domestic cargo flight was en route to Dallas Love Field Airport (DAL), Dallas, Texas.
Pilot Report
According to the pilot, after climbing to an altitude of 4,800 feet, the engine lost power. The pilot reversed course toward ELP and intended to land on runway 26R. However, the glide of the airplane did not reach the runway, resulting in a forced landing to a field, during which the wings and fuselage were substantially damaged.
Aircraft Information
The airplane was equipped with a Continental IO-520-BB87B engine, which had been modified by the addition of a Tornado Alley Turbo Whirlwind system under a supplemental type certificate. The turbocharger on the accident airplane was not part of the original modification; it was a Hartzell Engine Technologies unit (serial number HSGL00002) that had originally been sold to the operator on a factory remanufactured engine from Continental Motors in 2015 (TSIO-520-EB5B – serial number 1031058). According to the operator, they did not repair or modify the turbocharger, only loosened and tightened the V-band clamp and the hot side bolts. Investigators were unable to determine who modified the turbocharger prior to its installation on the accident airplane.
Examination Findings
Examination of the airframe and engine revealed thermal damage concentrated on the lower left side of the engine. The induction tube, forward of the turbocharger compressor, was melted, and its remains were found in the cowling below. The induction wye exhibited a hole emanating outward from the turbine wheel. The engine, magnetos, and related systems were otherwise unremarkable.
Disassembly of the turbocharger revealed that it had been reconfigured with a different compressor housing and the addition of wear washers. Evidence of high temperatures and thermal distress were noted on the turbine housing exhaust flange, the thrust collar, thrust spacer, and back plate. The turbine and compressor wheels exhibited evidence of rub within their housings. The turbine wheel hub showed evidence of hard rub with the center housing seal bore area. The turbine housing displayed red coloring on internal surfaces, bubbling of the exhaust flange, and spiraling tongue erosion, which according to Hartzell are consistent with high turbine inlet temperatures.