History of Flight
On August 14, 2011, about 0900 mountain daylight time, a Beech A36, registration N324AT, collided with terrain near Lander, Wyoming. The pilot/owner was operating under 14 CFR Part 91. The private pilot and passenger sustained fatal injuries; the airplane was destroyed by impact forces and post-crash fire. The cross-country personal flight had departed Driggs, Idaho, with a planned destination of Front Range Airport, Denver, Colorado. Visual meteorological conditions prevailed, and no flight plan was filed.
The pilot was using visual flight rules (VFR) flight following from Salt Lake City Air Route Traffic Control Center. The controller noticed a loss of radar contact and was unable to contact the pilot. An alert notice (ALNOT) was issued, and a search began. The wreckage was discovered about 1530 at 11,400 feet elevation in mountainous terrain, near the last radar contact.
Radar data reviewed by the National Transportation Safety Board investigator showed a target with a secondary 1200 (VFR) beacon code at a mode C altitude of 12,100 feet mean sea level (msl) about 10 nautical miles (nm) southeast of Driggs. The target flew a relatively straight track southeast toward the accident site, except for the last two targets, which showed a descending right turn.
About 52 miles southeast of Driggs, the target was at 15,100 feet. It switched to code 6060 and maintained it until data stopped. At 08:44:11.965, the target indicated 15,500 feet and held that altitude until a descent began at 08:54:16.135. The last transmission to Salt Lake Center was a check-in at 08:59:23.030 at 13,200 feet. At 09:00:01.455, the target was at 12,800 feet. The next target, 10.6 seconds later, showed a right turn and a 300-foot altitude loss. The final target, 10.5 seconds later (09:00:20.555), continued the turn with an additional 400-foot loss (final recorded altitude 12,100 feet). This target was less than 1 mile from the accident site, which was west of the target.
Personnel Information
The 71-year-old pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. He had a third-class medical certificate issued on February 28, 2011, with the limitation that corrective lenses must be worn. No personal flight records were located; the pilot reported a total time of 1,650 hours on his medical application.
Aircraft Information
The airplane was a Beech A36, serial number E-3071. Logbooks showed a total airframe time of 985.3 hours at the last annual inspection on July 1, 2011. The original factory piston engine had been replaced on November 6, 2000, with an Allison M250-B17F/2 (serial number CAE-881275) under supplement type certificate SA3523NM. Total engine time at the last annual inspection was 839.7 hours.
Meteorological Information
The nearest official weather station was Lander (KLND), 20 nm east of the accident site at 5,586 feet msl. A METAR issued at 0853 MDT reported: wind from 230 degrees at 18 knots; visibility 10 miles; sky 11,000 feet broken; temperature 22°C (72°F); dew point 6°C (43°F); altimeter 30.14 inches of mercury.
Wreckage and Impact Information
Investigators examined the wreckage on August 25, 2011. The airplane and engine were highly fragmented. Components at the first identified point of contact (FIPC) were scorched, but scattered debris was not. Identified parts included portions of both winglets, all control surfaces, rudder, both horizontal stabilizers, both elevators, and both ailerons.
The debris path was along a magnetic bearing of 280 degrees. The debris field was about 580 feet long and 180 feet wide, near the bottom of a hill sloping down to the left. The initial point of contact appeared upslope, with the right wing striking a large rock. A creek ran along the hill bottom, and many parts were in the creek and shoreline.
The FIPC was at 42°45.221' N, 109°9.194' W. It was an area of disturbed earth surrounded by boulders, containing a green lens fragment, a propeller blade fragment, right wing fragments, and white, blue, and dark red paint shards. Boulders in the debris path were dislodged with white scrape marks; scrape marks on the first displaced boulder were angled clockwise about 70 degrees.
The engine fragmented and lay a few feet past the FIPC. A nearby cluster of engine components included four stages of axial compressor wheels with numerous sheared blades; fracture surfaces were jagged and angular. Remaining blades were bent opposite the direction of rotation. Most propeller pieces were uphill from the FIPC, near the engine pieces.
The main wreckage included portions of the empennage, fuselage, and flight control cables in the approximate center of the debris field. The empennage pieces exhibited heavy leading edge crush damage.
Medical and Pathological Information
An autopsy performed by a pathology consultant for the Fremont County Coroner, Wyoming, determined the cause of death as multiple blunt force injuries. The FAA Forensic Toxicology Research Team performed toxicological testing on pilot specimens; tests for carbon monoxide or cyanide were not performed. No ethanol was found in muscle or liver. Atorvastatin was detected in the liver.
Tests and Research
The wreckage was examined at Beegle's Aircraft Service, Greeley, Colorado, on August 26, 2011. No evidence of preimpact mechanical malfunction was noted.
Airframe: The right aileron up cable from the chain around the sprocket to the fractured bellcrank was identified. Left aileron cable and balance cable continuity could not be confirmed as all components were not located. Portions of left and right ailerons, including one separated piece of right aileron with balance weights, were in place. The only aileron trim actuator, on the left side, measured 1 3/8 inch (neutral position). The right horizontal stabilizer's auxiliary structure and skins were missing from forward and aft spars. The left horizontal stabilizer had leading edge crush damage aft to the forward spar. Elevator control cables remained attached from the aft bellcrank to the forward swage ball; elevator push rods fractured at the bellcrank, were bent, and exhibited 45-degree shear lips. Tradewind elevator trim actuators on both sides measured 1 1/4 inch each. Rudder control continuity was established from the aft bellcrank to terminals at rudder forward push rods; the rudder trim actuator measured 1 inch. The landing gear operating mechanism fractured and separated; operating arm positions were consistent with gear retracted. The left flap actuator was not located; the right flap actuator measured 2.25 inches (retracted position). The fuel shutoff valve was not identified.
Engine: The engine data plate was not located. The compressor front support was crushed with rotational signatures. All four axial compressor wheels exhibited heavy rotational damage with numerous blades fractured at the wheel hubs; remaining blades were bent opposite rotation, with jagged fracture surfaces. The compressor impeller blades had heavy scoring and were bent opposite rotation from shroud contact. The turbine-to-compressor coupling fractured at the spline adaptor.