N324ATBeech A36 · 1997

On August 14, 2011, about 0900 mountain daylight time, a Beech A36, N324AT, collided with terrain near Lander, Wyoming. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (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 departed Driggs, Idaho, with a planned destination of Front Range Airport, Denver, Colorado. Visual meteorological conditions prevailed, and no flight plan had been filed.

The pilot was utilizing 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 on the radio. The controller issued an alert notice (ALNOT), and a search began. The wreckage was discovered about 1530; it was at 11,400 feet elevation in mountainous terrain in the vicinity of the last radar contact.

The National Transportation Safety Board investigator-in-charge (IIC) reviewed recorded radar data. A target with a secondary 1200 (VFR) beacon code at a mode C reported altitude of 12,100 feet mean sea level (msl) was observed about 10 nautical miles (nm) southeast of Driggs. The target maintained a relatively straight track to the southeast toward the accident site, except for the last two targets, which indicated a descending right turn.

About 52 miles southeast of Driggs, the target was at a mode C altitude of 15,100 feet. It switched to a secondary code of 6060, and maintained that code until the data stopped. The target indicated a mode C altitude of 15,500 feet at 08:44:11.965, and maintained that altitude until it began a descent at 08:54:16.135. The last transmission to Salt Lake Center was a check-in with Sector R5; this was at 08:59:23.030 at a mode C altitude of 13,200 feet.

At 09:00:01.455, the target was at 12,800 feet. The next target, about 10.6 seconds later, indicated a turn to the right, and an altitude loss of 300 feet. The next target, which was also the last target, was 10.5 seconds later (09:00:20.555); it continued the turn to the right with an additional loss of 400 feet (final recorded altitude of 12,100 feet). This target was less than 1 mile from the accident site, which was to the west of this target.

A review of Federal Aviation Administration (FAA) airman records revealed that the 71-year-old pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane.

The pilot held a third-class medical certificate issued on February 28, 2011. It had the limitation that the pilot must wear corrective lenses.

No personal flight records were located for the pilot. The pilot reported on his medical application that he had a total time of 1,650 hours.

The airplane was a Beech A36, serial number E-3071. A review of the airplane's logbooks revealed that the airplane had a total airframe time of 985.3 hours at the last annual inspection dated July 1, 2011.

According to the airplane's maintenance logbooks, the original factory piston engine had been changed on November 6, 2000, by Tradewind Turbines, Inc. They changed it to an Allison M250-B17F/2, serial number CAE-881275, under supplement type certificate (STC) SA3523NM. Total time recorded on the engine at the last annual inspection was 839.7 hours.

The closest official weather observation station was Lander (KLND), which was 20 nautical miles (nm) east of the accident site at an elevation of 5,586 feet mean sea level (msl). An aviation routine weather report (METAR) for KLND issued at 0853 MDT stated: wind from 230 degrees at 18 knots; visibility 10 miles; sky 11,000 feet broken; temperature 22/72 degrees Celsius/Fahrenheit; dew point 6/43 degrees Celsius/Fahrenheit; altimeter 30.14 inches of mercury.

The airplane was a Beech A36, serial number E-3071. A review of the airplane's logbooks revealed that the airplane had a total airframe time of 985.3 hours at the last annual inspection dated July 1, 2011.

According to the airplane's maintenance logbooks, the original factory piston engine had been changed on November 6, 2000, by Tradewind Turbines, Inc. They changed it to an Allison M250-B17F/2, serial number CAE-881275, under supplement type certificate (STC) SA3523NM. Total time recorded on the engine at the last annual inspection was 839.7 hours.

Investigators examined the wreckage at the accident scene on August 25, 2011. A detailed report is part of the public docket.

The airplane and engine were highly fragmented; components at the first identified point of contact (FIPC) were scorched, but components that were scattered throughout the debris field were not. Portions of the left and right winglets, all control surfaces, rudder, both horizontal stabilizers, both elevators, and both ailerons were identified.

The debris path was along a magnetic bearing of 280 degrees, and further references are relative to the debris path. The debris field was about 580 feet long and 180 feet wide, and near the bottom of a hill that sloped down to the left. The initial point of contact appeared to be upslope with the right wing contacting a large rock. A creek ran along the bottom of the hill, and numerous parts were in the creek and its shoreline.

The FIPC was at 42 degrees 45.221 minutes north latitude 109 degrees 9.194 feet west longitude. The FIPC was an area of disturbed earth surrounded by boulders. It contained a green lens fragment, a propeller blade fragment, right wing fragments, and paint shards that were white, blue, and dark red.

Boulders in the direction of the debris path were dislodged, and contained white scrape marks. The scrape marks along the first displaced boulder were angled clockwise about 70 degrees.

The engine fragmented, and was a few feet past the FIPC. A nearby cluster of engine components included four stages of axial compressor wheels with numerous blades sheared off on each wheel; the fracture surfaces were jagged and angular. The remaining blades sustained damage, and were bent opposite the direction of rotation.

The majority of the propeller pieces were uphill from the FIPC, and near the engine pieces.

The main wreckage included portions of the empennage, fuselage, and flight control cables; these pieces were in the approximate center of the debris field. The empennage pieces exhibited heavy leading edge crush damage.

A pathology consultant for Fremont County Coroner, Wyoming, completed an autopsy, and determined that the cause of death was multiple blunt force injuries.

The FAA Forensic Toxicology Research Team, Oklahoma City, Oklahoma, performed toxicological testing of specimens of the pilot. They did not perform tests for carbon monoxide or cyanide.

Analysis of the specimens contained no findings for ethanol in muscle or liver.

The report contained the following findings for tested drugs: atorvastatin detected in liver.

The wreckage was examined at Beegle's Aircraft Service, Greeley, Colorado, on August 26, 2011. No evidence of preimpact mechanical malfunction was noted during the examination. A detailed report on the examination is in the public docket.

Airframe

The right aileron up cable from the chain around the sprocket to the bellcrank, which fractured was identified. Left aileron cable operating and balance cable continuity could not be confirmed as all components were not located. Portions of the left and right ailerons including one separated piece of right aileron with balance weights were in place. The only aileron trim actuator was measured, which was on the left side, at 1 3/8 inch; this equated to the neutral position.

The auxiliary structure and skins were missing from the forward and aft spars for the right horizontal stabilizer. The left horizontal stabilizer had leading edge crush damage that went aft to the forward spar.

The elevator control cables remained attached from the aft elevator bellcrank to the forward swage ball. The elevator push rods fractured at the bellcrank; were bent, and exhibited 45-degree shear lips.

The airplane had Tradewind elevator trim actuators installed on both sides. Both the left and right actuators measured 1 1/4 inch.

Rudder control continuity was established from the aft bellcrank to the terminals at rudder forward push rods. The rudder trim actuator measured 1 inch.

The landing gear operating mechanism fractured and separated; the position of the operating arms were consistent with the gear retracted position

The left flap actuator was not located. The right flap actuator measured 2.25 inches, which equated to the retracted position.

The fuel shutoff valve was not identified

Engine

The engine data plate was not located.

The compressor front support was crushed, and exhibited rotational signatures. All four axial compressor wheels exhibited heavy rotational damage with numerous blades fractured and separated at the wheel hubs. The remaining blades were bent opposite the direction of rotation; the fracture surfaces were jagged and angular. The compressor impeller blades exhibited heavy scoring, and the blades bent opposite the direction of rotation from shroud contact.

The turbine to compressor coupling fractured at the spline adaptor.