NTSB Factual Report

On September 1, 2015, about 0930 mountain standard time, a Lancair Super ES, N74ES, was destroyed during a forced landing and subsequent post-impact fire after experiencing a loss of engine power in cruise flight near Winkelman, Arizona. The private pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the flight, which departed El Paso International Airport (ELP), El Paso, Texas, about 0820, and was destined for Glendale Municipal Airport (GEU), Glendale, Arizona. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91.

The pilot stated that his preflight inspection, engine run up, and departure were uneventful with no anomalies noted. He departed ELP with about 50 gallons of fuel onboard for the 316-nautical-mile flight, and climbed the airplane to a cruise altitude of 8,500 feet mean sea level (msl). About 1 hour into the flight, the pilot noted a "slight" loss of engine power and observed the exhaust gas temperature (EGT) indications from all 6 engine cylinders "fluctuating." The pilot adjusted the fuel mixture, and stated that about 30 seconds later, the engine stopped producing "most" of its power and was "struggling to stay running." He then manipulated the throttle, mixture, and propeller controls, but none of these inputs produced any response from the engine. The pilot established the airplane's best glide speed and elected to land the airplane on a rocky plateau. The airplane came to rest upright and the pilot egressed. The airplane was subsequently consumed by a post-impact fire.

The pilot held a commercial pilot certificate with ratings for rotorcraft-helicopter and instrument helicopter, and a private pilot certificate with a rating for airplane single engine land. He did not hold a current Federal Aviation Administration (FAA) medical certificate. The pilot reported 1,650 total hours of flight experience, of which 240 hours were in the accident airplane make and model.

The experimental amateur-built airplane was issued an FAA airworthiness certificate in 2000. It was equipped with a Continental IO-550 series, 310-hp reciprocating engine. The airplane's most recent annual inspection was completed on October 24, 2014. At the time of the accident, the airframe and engine had accumulated about 620 total hours of operation. According to the pilot, the engine underwent extensive maintenance about 100 hours prior to the accident, including honing of the cylinder barrels and replacement of the crankshaft and camshaft; however, despite repeated requests, the pilot did not provide documentation of this maintenance.

The engine was examined on March 13, 2016. The engine remained attached to its mount, which was separated from the airframe. The engine and all components exhibited significant thermal damage, and all steel components were rusted. The crankshaft could not be rotated due to thermal damage. The propeller remained attached to the crankshaft, and all three blades exhibited s-bending and leading edge damage. The exhaust system remained attached to the cylinders, and the intake filter and tube upstream of the throttle body were not observed.

The right magneto remained attached to the engine, and the left magneto mounting location contained a cover plate, indicative of an electronic ignition system; however, the ignition control was not observed and was presumed destroyed by the post-impact fire. All fuel lines remained attached to their respective fittings, and the housing around the fittings was partially melted away. The fuel metering unit and throttle body fittings were secure. The throttle and mixture cables remained attached to their respective levers; however, the controls could not be manipulated due to thermal damage.

All six cylinders remained attached to the crankcase and exhibited little-to-no combustion deposits; consistent with prolonged lean fuel/air mixture operation. Numerous cylinder through-bolts were displaced from the engine case, and several through-bolt nuts and cylinder attach nuts were fractured; however, the crankcase and main bearings did not display any evidence that indicated that the through-bolts were displaced prior to the post-crash fire.

NTSB Probable Cause

A partial loss of engine power for reasons that could not be determined because postaccident examination of the engine revealed no anomalies.