CEN18FA024

The pilot's failure to maintain airspeed during the initial climb after takeoff, which resulted in the airplane exceeding its critical angle of attack and a subsequent aerodynamic stall/spin.

The private pilot and 3 passengers departed the airport on a return cross-country flight; the wreckage was located the following evening in rugged, desert terrain about 0.56 nautical mile west of the departure end of the runway. About the estimated time of the accident, the reported wind was from 220° at 15 kts gusting to 18 kts, the calculated density altitude was 6,371 ft, and the airplane would have been taking off toward the setting sun. The airplane's estimated takeoff weight was about 25 lbs below its maximum gross weight. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The impact damage to the airplane was consistent with an aerodynamic stall/spin which, given the location of the wreckage relative to the runway, likely occurred during the initial climb after takeoff. It is likely that the airplane's high gross weight, the high density altitude and gusting wind conditions were factors which contributed to the pilot's failure to maintain adequate airspeed during the initial climb after takeoff. The low airspeed resulted in the airplane exceeding its critical angle of attack and a subsequent aerodynamic stall/spin. Toxicology testing of the pilot detected venlafaxine, an antidepressant medication, in liver and blood specimens. There were no documented adverse side effects to the pilot, so it is unlikely that this medication resulted in impairment or incapacitation. An autopsy identified moderate coronary artery disease without angina with 3 stent placements. Whether the pilot experienced impairing symptoms from his cardiovascular condition or if it contributed to the accident could not be determined.

The Office of the Medical Investigator, Albuquerque, New Mexico, performed an autopsy of the pilot. The cause of death was from multiple blunt force injuries. The autopsy identified moderate coronary artery disease without angina with 3 stent placements. Toxicology testing performed at the FAA Forensic Sciences Laboratory detected no carbon monoxide in blood and no ethanol in vitreous. The testing indicated 2.206 (µg/mL, µg/g) desmethylvenlafaxine (O-) in the liver; 0.856 (µg/mL, µg/g) desmethylvenlafaxine (O-) in the blood; 0.575 (µg/mL, ug/g) venlafaxine in liver; and 0.252 (µg/mL, µg/g) venlafaxine in blood. Venlafaxine is an antidepressant medication. Desmethylvenlafaxine is a metabolite of venlafaxine. At 1635, the surface weather observation at Las Cruces International Airport (LRU), Las Cruces, New Mexico, located 27 nm south of the accident site, included wind from 220° at 15 kts, gusting to 18 kts; 10 miles visibility; clear skies; temperature 23°C; dew point 6°C; altimeter 30.05 inches of mercury. On November 4, 2017, sunrise at Hatch, New Mexico, was at 0729 and sunset was at 1815. At 1730, the solar azimuth was 245.54° and the solar elevation was 8.1°. The elevation at E05 was 4,456 ft. The calculated density altitude at 1635 was 6,371 ft. The 57-year-old pilot held a private pilot certificate issued on September 23, 2016, with a single-engine land rating. On the application for that certificate, he reported 139.6 total hours of flight experience. The pilot's logbook was not obtained during the course of the investigation. He held a third-class FAA airman medical certificate that was issued on August 25, 2016. The on-site examination of the wreckage revealed that the airplane impacted terrain in a steep, left-wing-low, nose-down attitude on a 110° heading. A piece of the left wingtip and red navigation lens was found near the initial impact point. The step from the left strut was found 17 ft to the right of the left wingtip's initial impact point. A depression in the sand stretched from the initial impact point to a 5-ft-by-4-ft depression in the sand that was located near the left step. Pieces from the nose of the airplane and engine cowling were found in the depression. A 25-ft skid mark stretched across the sand from the depression to where the engine and propeller were located in front of the main wreckage. The nose of the airplane was aligned on a 020° heading. First responders reported that the tail of the airplane was initially found in a near-vertical position, but it had fallen back down and was resting on the ground. The left wing exhibited aft crushing of the outboard section of its leading edge. The left wing was buckled and broken about mid-span and the left wing strut was buckled. The left wheel was separated from the left landing gear. The aileron and flap remained attached to the wing. No fuel was found in the left fuel tank and the fuel lines were broken at the wing root. The 25-gallon fuel tank exhibited hydraulic deformation, with the forward section of the fuel tank bulging out and the rear of the tanks sucked in. There were no apparent fuel stains on the sandy soil. The right wing exhibited aft crushing of the wingtip. The rest of the wing, including the strut, remained largely intact. The right wheel remained attached to the right landing gear and did not exhibit any impact damage. The aileron and flap remained attached to the wing. No fuel was found in the right fuel tank and the fuel lines were broken at the wing root. The 25-gallon fuel tank exhibited hydraulic deformation, with the forward section of the fuel tank bulging out and the rear of the tanks sucked in. There were no apparent fuel stains on the sandy soil. The empennage remained attached to the fuselage and no impact damage was evident to the vertical and horizontal stabilizers or their control surfaces. The airplane's tail was found buckled aft of the rear passengers' seats and offset to the left of the cabin and fuselage. The examination of the cabin and engine compartment revealed extensive downward and aft buckling and crushing of the airframe structure. The engine remained attached to the firewall and engine mount. Numerous fractures were observed that were consistent with overload fractures. The engine firewall was bent aft and down. The cockpit exhibited damage consistent with downward and aft crushing and buckling. The fuel strainer was intact. The fuel strainer bowl and screen were clean; however, a light blue rubbery material (similar to RTV blue silicone gasket sealant) was observed around the top of the fuel strainer screen. The examination of the cockpit revealed that the ignition switch was in the BOTH position, and the master battery and alternator switches were on. The fuel selector handle was found in the BOTH position. The fuel selector valve was found in the off position; however, the shaft for the fuel selector valve exhibited impact damage and was bent. The throttle was found in the full-power position and the throttle cable was still connected to the carburetor. The mixture was in the full-rich position, but the mixture cable was separated at the carburetor. The carburetor heat was in the cold position, but the carburetor air/heat box was crushed from impact forces. Most of the instruments were destroyed; the airspeed indicator needle indicated 46 kts, the altimeter indicated 5,800 ft, the vertical speed indicator indicated a 300 ft-per-minute descent, and the altimeter Kollsman window displayed 29.95. The engine tachometer indicated 300 rpm and displayed 1,232.5 hours of operation. The elevators, rudder, and flaps exhibited control continuity from the cockpit controls to the control surfaces. Aileron control continuity was established to the left aileron. The right aileron push/pull rod from the wing bellcrank to the aileron was separated, and the rod end was bent and displayed a fracture surface consistent with overload. The flap indicator in the cockpit was in the extended position, but the flap actuator was found in the retracted position. The engine was separated from the airframe and the propeller was removed from the engine. The crankshaft was rotated by hand utilizing the vacuum pump drive, and thumb compression was obtained in proper firing order. Mechanical continuity of the drivetrain was established during the rotation of the crankshaft. Each of the valve rockers moved in normal order. Cylinder borescope examination revealed no evidence of foreign object ingestion or detonation to any of the cylinders. The left and right magnetos remained secure at their respective mounting pads. The magnetos were removed and produced spark at each lead during hand rotation of the drive. The Champion REM-40E spark plugs remained secure at each cylinder with their respective lead attached. The top spark plugs were removed and exhibited no mechanical damage at each electrode. The coloration was consistent with normal operation. The carburetor was separated from the engine at the mounting flange. The fuel filter inlet screen was free of visible contaminants. The carburetor was opened for examination. The plastic floats remained undamaged and securely mounted. There was no fuel observed, and there were no visible contaminants observed in the bowl. The air filter was crushed. There were no foreign objects observed in the carburetor air passage. The propeller remained attached to the crankshaft flange. The flange exhibited impact damage and was bent, and the metal spinner was crushed. The blades remained intact. One propeller blade exhibited significant leading-edge damage, chordwise striations, trailing edge "S" bending and torsional twisting. The opposing blade exhibited leading edge damage and moderate chordwise striations. The signatures were consistent with rotational energy at the time of impact. The four-seat, single-engine airplane, serial number 1727105, was manufactured in 1978.