History of Flight
On April 9, 2016, at 0951 central daylight time, a Rockwell International 690B, registration N690TH, was destroyed when it struck terrain while maneuvering near Taylor, Texas. The private pilot and flight instructor sustained fatal injuries. The aircraft was privately owned and operated under 14 CFR Part 91. Visual meteorological conditions existed, and no flight plan was filed for the local instructional flight, which had departed from Georgetown Municipal Airport (GTU), Georgetown, Texas, at 0941.
An acquaintance of the pilot reported that the flight was intended for annual recurrent training to meet insurance requirements. During a preflight walkaround, the acquaintance overheard the instructor telling the pilot they would perform "air work" at 4,000–5,000 ft altitude followed by instrument approaches. The acquaintance considered that altitude for air work to be low, suggesting at least 10,000 ft.
Radar data indicated the airplane departed GTU and proceeded east, climbing to about 5,500 ft mean sea level (5,000 ft above ground level). Approximately five minutes after takeoff, the airplane completed one 360° left turn, followed by one 360° right turn. It then resumed eastward level flight for about two minutes, decelerating to a ground speed of 90 knots before entering a rapid descent.
A witness near the accident site stated the airplane entered a low-altitude turn, then went "totally sideways" and "started coming down" as if performing "tricks." The left wing pointed skyward and the right wing toward the ground. The engine sound was described as "slow" and did not change during the maneuver. The airplane descended with the nose pointing straight down.
Personnel Information
The pilot registered the airplane on April 23, 2015, and received dual flight instruction in the accident aircraft from April 13 to May 25, 2015, totaling 34.2 hours. A logbook endorsement dated May 15, 2015, indicated completion of a flight review, pilot-in-command landing proficiency, and an instrument competency check.
The 54-year-old pilot held an FAA third-class medical certificate. The 66-year-old flight instructor held an FAA second-class medical certificate.
Aircraft Information
According to the Model 690B Pilot's Operating Handbook, Section II Limitations, the stall speed with landing gear and flaps retracted at gross weight (Vs) was 78 knots indicated airspeed (KIAS), and the minimum controllable airspeed (Vmca) was 83 KIAS.
Wreckage and Impact Information
The aircraft came to rest upright in a field on a magnetic heading of about 130° and was consumed by postcrash fire. The empennage was folded forward; both wing leading edges were crushed aft. The flap control mechanism was consistent with flaps up. The elevator trim tab was about 16.4° down (nose-up). Flight control system separations were consistent with overload throughout. The nose, forward fuselage, both engines, and propellers were embedded about 3 ft into the ground. Both propellers exhibited S-shaped bending, twisting, and chordwise scratching. Left and right propeller piston signatures indicated blade angles of about 18.6° and 15.5°, respectively.
The left engine throttle control was in the forward position; the right engine throttle was in about the mid-position. The left engine condition lever was broken off; the right engine condition lever was forward.
Examination of both engines revealed extensive impact damage; neither could be rotated by hand. First-stage impeller blades were bent opposite the direction of rotation, and debris in the first compressor stage was consistent with ground impact. Metal deposits were found on turbine rotors and stators, indicating engine operation at impact. No mechanical anomalies precluding normal operation were found.
Medical and Pathological Information
Medical records showed the pilot had high blood pressure treated with the non-impairing medication valsartan. An autopsy performed by Central Texas Autopsy PLLC listed the cause of death as multiple blunt force injuries; the examination was limited externally due to injury extent and did not identify significant natural disease. Toxicology testing by NMS Labs detected caffeine, acetaminophen, and ethanol in muscle. The toxicologist noted the ethanol concentration increased from 45 to 78 mg/100 g over multiple analyses, possibly due to decomposition.
The flight instructor had high blood pressure treated with metoprolol and obstructive sleep apnea treated with a CPAP device. His autopsy also listed multiple blunt force injuries and was limited to external examination. Toxicology detected acetaminophen, beta-phenethylamine (a decomposition product), and a non-quantified amount of ethanol in muscle.
The FAA Bioaeronautical Sciences Research Laboratory performed toxicology on comingled remains; it was not possible to reliably attribute specimens to each individual. Testing attributed to the pilot documented no valsartan or ethanol, but detected tetrahydrocannabinol (THC) at 35.2 ng/g in liver, 52.9 ng/g in lung, and a non-quantified amount in muscle, along with its metabolite THC-COOH. Testing attributed to the instructor found ethanol at 20 mg/dL in liver and heart, dextromethorphan (a cough suppressant) in liver, kidney, and muscle, and valsartan in liver. The report stated THC and THC-COOH were not detected in muscle attributed to the instructor. Dextromethorphan is generally not considered impairing at therapeutic levels.