CEN16FA034

The pilot's loss of airplane control during the turn back to the airport after takeoff in high density altitude conditions, which resulted in an inadvertent aerodynamic stall and subsequent spin. Contributing to the accident was the pilot's impaired performance due to his use of a combination of potentially impairing medications.

The private pilot and his passenger departed on a cross-country flight. Shortly after takeoff, the pilot reported to the controller that he was having an engine problem and wanted to return to the airport. One witness heard the engine surge during the takeoff roll. Another witness stated that the airplane was on the ground longer than he expected but did not report hearing anything abnormal with the engine. A third witness stated that the engine sounded normal and a fourth witness reported seeing the airplane in a steep bank. The airplane was damaged by impact and a postimpact fire. An examination of the engine, propeller, airframe, and related systems revealed no anomalies that would have precluded normal operation prior to the accident. The damage to the airplane and the witness marks on the ground were consistent with the airplane being in a flat spin at the time of impact. The density altitude at the time of the accident was 7,446 ft mean sea level. The majority of the pilot's flight experience was conducted at airports with a lower field elevation and he had flown to the accident airport on only two other occasions. It is likely that, after takeoff, the pilot misinterpreted the airplane's reduced engine power and decreased climb performance, due to the high density altitude conditions, as an engine malfunction. During the turn back to the airport the pilot exceeded the airplane's critical angle of attack and experienced an aerodynamic stall and spin. Although there was evidence that the pilot had used marijuana at some time prior, it is unlikely that the pilot was impaired by marijuana at the time of the accident. The pilot had been diagnosed with mild depression two months before the accident and had started treatment with sertraline. The pilot had not yet followed-up with his physician after starting treatment. Therefore, the investigation was unable to determine if the pilot may have been impaired by the symptoms of his depression. The pilot was using diphenhydramine, cetirizine, and sertraline, which in combination significantly increased the risk of impairment over each medication alone. The experienced pilot was exposed to a high workload environment following the degradation of airplane performance, but would have been expected to safely fly the airplane. Therefore, it is likely that when the pilot was exposed to a high workload environment, due to the airplane's degraded takeoff performance, the combination of multiple medications likely impaired his ability to respond safely and, therefore contributed to the subsequent loss of control.

The El Paso County Coroner performed the autopsy on the pilot on November 10, 2015. The autopsy concluded that the cause of death was multiple blunt force injuries and the report listed the specific injuries. The manner of death was accident. Although the autopsy was limited due to the extent of injury, no evidence of natural disease was found. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological tests on specimens that were collected during the autopsy. Results were negative for carbon monoxide and ethanol. The testing detected sertraline at 90 ng/ml, diphenhydramine at 52 ng/ml, and cetirizine in cavity blood. Both diphenhydramine and cetirizine are potentially impairing. Additionally, Rosuvastatin, a prescription cholesterol-lowering medication, and salicylate, a metabolite of aspirin, were detected in urine. Tetrahydrocannabinol (THC), the psychoactive component of marijuana, was detected in lung, but not cavity blood, and its inactive metabolite tetrahydrocannabinol carboxylic acid was detected in tissues and urine. The El Paso County Coroner toxicology urine drug test was positive for tetrahydrocannabinol carboxylic acid (THC-COOH), diphenhydramine, and naproxen. Femoral blood tested positive for diphenhydramine at less than 50 ng/ml. A review of the pilot's medical history revealed that the pilot had reported elevated cholesterol to the FAA for many years. As of his most recent medical certification examination had reported the use of Rosuvastatin and niacin, cholesterol-lowering medications that are not generally considered impairing. Two months before the accident the pilot was diagnosed with depression and had started treatment with the antidepressant medication sertraline. Although the medication is not generally considered impairing, symptoms from depression may be. For more information, see the Medical Factual Report in the docket. The closest official weather reporting station was COS located just south, southeast of the accident site. The routine aviation weather report (METAR) for COS recorded the wind at 200° at 8 knots, sky condition broken clouds at 23,000 ft, temperature 14° Celsius, dewpoint temperature -13° Celsius, and an altimeter setting of 29.99 inches of mercury. Calculations using relevant meteorological data indicated that the density altitude was 7,446 ft. The FAA Airplane Flying Handbook and the performance data in the Cirrus Design SR22 Pilot's Operating Handbook both discuss the negative effect of density altitude on airplane performance. The pilot, age 63, held a private pilot certificate with airplane single engine land and instrument airplane ratings. He was issued a third class medical certificate on November 4, 2013. The certificate contained the limitation "Not valid for night flying or by color signal control. Must wear corrective lenses." Remains of a Taxlog Tax record flight log were found adjacent to the main wreckage. The start date on the first page of the log could not be determined due to fire damage. The first flight appeared to be a business flight with the duration of 6.6 hours. The start "tach" time was 1,309.8 and the stop "tach" time was 1,316.4. There were 19 pages of records with the first discernable date starting on page 6 of the record in 2009. All of the flights recorded in the log were in the accident airplane. The last entry on the 19th page was dated March 17, 2015, and was from 52F to AEE/VGT, with a start time of 3,095 and end time of 3,108.2. Two flights before that, dated February 19, 2015, the pilot successfully completed the requirements of a flight review and an instrument proficiency check in the airplane. The flight was 2.7 hours in duration and included 3 landings and 3 instrument approaches. Based upon the remains of this flight log, the airplane was likely based at 52F as the flights recorded all appeared to originate from 52F. This airport was located 3 miles northwest of Roanoke, Texas, at an elevation of 643 ft mean sea level (msl). This flight log reflected that the pilot had flown to COS on two other occasions. The pilot had also flown to Albuquerque, New Mexico, on two different occasions; ABQ at an elevation of 5,354 ft msl and AEG at an elevation of 5,837 ft msl. Otherwise, the majority of the pilot's flying was conducted out of airports with field elevations below 1,000 ft msl. On the pilot's medical certificate application, dated October 4, 2011, he reported a total flight time of 2,350 hours. He did not report total flight time on the more recent application dated November 4, 2013. The airplane came to rest in a field about 1/2 mile north of the departure end of runway 35L. The accident site was located in an open field at an elevation of 6,200 ft msl, and the airplane came to rest on a heading of 270°. A large ground scar was located just to the east of the main wreckage. The scar was about 30 ft in length with three prominent craters consistent in location/position with the main landing gear and the engine. Fragments of fiberglass were located in each of the three craters. The field where the airplane crashed was burned in a radius immediately surrounding the wreckage and then to the north at least a half mile. The airplane was upright, and the wreckage included the fuselage, engine and propeller assembly, both wings, and the empennage. The entire wreckage was charred, melted, and partially consumed by fire. The fuselage included four seats, personal effects, and the instrument panel. The left cabin door separated from the airframe and was located 45 ft to the west of the wreckage. The right cabin door separated from the airframe and was located 45 ft to the north of the wreckage. The instrument panel was impact and fire damaged and provided the following information: Kollsman window 30.01 Attitude indicator 20° nose down Airspeed indicator 0 knots The engine gauges and remaining instruments did not provide any reliable readings. Both the fuel mixture control and the engine throttle control were found in the forward position in the cabin. Impact and fire damage precluded a functional check of these control cables. The engine throttle was in the idle position at the engine, and the cable was stretched in tension. The fuel mixture was close to full rich at the engine, and the control cable rod end was impact damaged. The fuel selector valve handle was in the left detent, and the shaft was separated. The fuel selector valve assembly was disassembled, and the valves were in a position consistent with the right fuel tank being selected. Seatbelt assemblies consistent with lap belts and shoulder harnesses were found latched for both front seat occupants. Pilot and passenger seat energy absorption modules were crushed flat. The right wing remained partially attached to the fuselage and included the right aileron and right flap. The right wing, right aileron, and right flap were charred, melted, and partially consumed by fire. Control continuity to the right aileron was confirmed from the right aileron actuation pulley inboard to the center portion of the fuselage. The right main landing gear separated and came to rest directly under the right wing. The right main landing gear assembly was charred, melted, and partially consumed by fire. The left wing remained partially attached to the fuselage and included the left aileron and left flap. The left wing, left aileron, and left flap were charred, melted, and partially consumed by fire. Control continuity to the left aileron was confirmed from the left aileron actuation pulley inboard to the center portion of the fuselage. The left main landing gear remained partially attached and came to rest directly beneath the left wing. The left main landing gear assembly exhibited exposure to heat and fire. The flap actuator jack screw was extended about 2 inches, consistent with 50% or 16° of flap extension. The empennage