WPR17FA166

A loss of control during takeoff for reasons that could not be determined.

The private pilot and three passengers departed on a cross-country flight in the turbocharged single-engine airplane. Witnesses saw the airplane during the takeoff and reported that about 3,700 ft down the 5,195-ft-long runway, the airplane was about 100 ft above the runway surface. The witnesses also noticed that the engine sounded "underpowered" and that the tail of the airplane was moving up and down as if the pilot was struggling to keep the airplane airborne. The airplane continued its climbout, and soon after, the pilot communicated to the tower controller that the airplane was "going down." The airplane impacted the right side of a north-bound freeway. Detailed examination of the airplane, engine, and propeller did not reveal any pre-impact mechanical deficiencies that would have precluded normal operation. Given the weights of the pilot, passengers, and fuel onboard, the airplane was near its maximum gross weight about the time of the accident. Additionally, the density altitude was about 6,500 ft. Both of these factors would have resulted in an increased takeoff distance and reduced climb performance, though review of performance data indicated that the runway available was adequately long to accommodate the airplane's predicted takeoff roll (2,109 ft) and distance to clear a 50-ft obstacle (3,401 ft). Although the actual loading of the airplane at the time of the accident could not be accurately determined, including the weight and location of any baggage and the positions of the rear passengers, it is likely that the airplane's center of gravity (CG) was outside of its forward end of the envelope as depicted on a weight and balance worksheet. A forward CG can result in nose heaviness and increased stall speed. The pilot chose to operate the airplane under conditions which would have adversely affected its performance, namely, high gross weight, high density altitude, and with a CG that may have been forward of prescribed limits. Whether the pilot calculated the airplane's weight and balance before the flight and was prepared for the resulting negative effects on its takeoff performance could not be determined. Given the lack of anomalies observed during postaccident examination, it is unlikely that the pilot experienced a loss of engine power or mechanical failure during the takeoff; therefore, the reason for the pilot's loss of control shortly after takeoff could not be determined.

The 1153 weather observation at OGD included calm wind, 10 miles visibility, clear skies, temperature 25°C, dew point 14°C, and an altimeter setting of 30.22 inches of mercury. At 1253, wind was from 270° at 5 knots with 10 miles visibility, clear skies, temperature 26°C, dew point 14°C, and an altimeter setting of 30.21 inches of mercury. The density altitude about the time of the accident was about 5,514 ft. The pilot, age 48, held a private pilot certificate with ratings for airplane single-engine land and instrument airplane rating. His most recent FAA third-class airman medical certificate was issued on October 22, 2015, with no limitations. The pilot reported no flight experience on the medical application. The pilot's logbook revealed a total of 396 hours of flight experience, which included 196 hours in the accident airplane. In the last 6 months, he had about 28 hours of flight experience, of which about 26 were in the accident airplane. The initial impact point was located on the ground near the outer edge of the northbound side of the freeway about 1 mile south of the departure end of runway 17. The airplane came to rest in the median along the center guardrail. The debris field was about 150 ft long with debris in both north- and southbound lanes. (See Figure 1). The main wreckage remained intact and displayed extensive postcrash fire damage. The wing tip tanks and the leading edges of the wings were crushed, consistent with vertical impact damage. All flight controls were accounted for and flight control continuity was confirmed. The propeller assembly separated from the engine during the accident sequence and was subsequently relocated about 200 ft from the debris field after being struck by a passing tractor-trailer. No other vehicles were involved in the accident sequence. Figure 1-Aerial View of the Accident Site Airframe The wreckage was relocated to a hangar at OGD for further examination. The rudder and elevator trim tab actuator measurements were unreliable due to impact damage. The left flap actuator indicated about 2° of extension, and the right flap actuator position could not be determined. The fuel system was compromised due to impact and thermal damage. The fuel selector valve was found in the right main tank position. The fuel strainer was disassembled and was free of debris. The tip tanks displayed hydraulic deformation consistent with fuel being present in the tank during impact. No fuel was found during the examination. The landing gear was found in the retracted position. All cabin seats separated from their attach points and were loose in the wreckage. Engine The engine was shipped to the Continental Motors facility in Mobile, Alabama, for a teardown examination. The examination did not reveal any preaccident anomalies with any of the internal engine components. Disassembly of the fuel pump did not reveal any preaccident anomalies that would have precluded normal operation. The fuel pump drive coupling was fractured consistent with impact damage. The propeller governor separated from the engine during the impact sequence and exhibited impact and thermal damage. The internal gears separated from the housing and were undamaged. The propeller governor was disassembled, and the internal flyweights remained intact and capable of normal movement. The turbocharger separated from the engine and exhibited impact and thermal damage. The turbocharger driveshaft was seized and could only be rotated slightly with the use of a wrench. The turbocharger was partially disassembled, and the internal surfaces of the scrolls were not visibly damaged. The turbocharger controller, wastegate, and overboost valve displayed thermal and impact damage. The turbocharger was shipped to Hartzell Engine Technologies, Montgomery, Alabama, for further examination. The examination revealed no anomalies. Propeller The propeller assembly did not exhibit any evidence of mechanical malfunctions or anomalies. All damage was consistent with high impact forces and the blade damage was indicative of rotation with engine power at the time of impact. The airplane was manufactured in 1981 and was equipped with a Continental TSIO-520-NBcUB series engine. The pilot purchased the airplane in May 2014. A review of maintenance records indicated that the airplane's most recent annual inspection was completed on May 16, 2017, at a tachometer and airframe total time of 3,612.5 hours. The engine logbook indicated that the engine was overhauled in February 2009. The most recent engine logbook entry was dated May 16, 2016, which indicated that the engine had accrued 493.18 hours since overhaul. The airplane was equipped with a three-bladed Hartzell PHC-C3YF-1RF propeller. The propeller was installed in February 2005, and the governor was overhauled in February 2009. Fueling records obtained from OGD revealed that the airplane was serviced with 23.3 gallons of 100LL aviation fuel the morning of the accident flight. The airplane's co-owner stated that he and the accident pilot bought the airplane 3 years before the accident and that they had no problems with it other than some minor avionics issues. They always refueled with the main fuel tanks to the tabs (60 gallons total, 54 gallons useable) and the wing tip tanks half full (20 gallons total). His reason for the half full tip tanks was to keep the tanks wet, and for managing aircraft weight. He further stated that they had flown the airplane four to six times since the last annual inspection. The co-owner further reported that their customary procedure was to lean the mixture by four turns of the knob during taxi. During engine runup, they would lean further, and for takeoff, they would adjust the mixture to the full rich position. They always performed takeoffs with the wing flaps retracted. He added that he and the accident pilot sometimes flew together and, during takeoff from runway 17 at OGD, they would use the intersection with runway 3/21 as a visual cue for aborting the takeoff, if the takeoff roll was too long. Airplane Weight and Balance The most recent weight and balance record for the airplane was dated April 10, 2015, and indicated that the airplane's maximum gross weight was 3,650 lbs. The airplane was equipped with a wing tip tank supplemental type certificate (STC), which increased the maximum gross weight to 3,833 lbs. Despite postimpact fire damage, there was no evidence of any large suitcases, bags or cargo items in the airplane at the time of the accident. Based on the weights of the pilot, passengers, and fuel, and allowing for 40 lbs of baggage, the calculated gross weight of the airplane at the time of the accident was about 3,853 lbs. The actual loading of the airplane at the time of the accident, including baggage weight and location and position of the rear passengers, could not be accurately determined. When the weight data was added to a center of gravity moment worksheet, the airplane's center of gravity was outside the worksheet's envelope. Airplane Takeoff Performance Takeoff performance distance data for the airplane were presented in graph form in the pilot's operating handbook (POH). The performance chart values were predicated on the following conditions: - Gross weight: 3,650 lbs - Power: "Take-off Power Set Before Brake Release" - Flaps: 0º - Landing gear retracted after lift-off - Runway: paved, level, dry surface - Takeoff speeds: lift off, 74 kts; 50 ft height, 80 kts POH-derived takeoff distances calculated using the ambient conditions, level runway, 3,650 lb weight, and no wind component were a ground roll distance of 1,900 ft and a distance to clear a 50-ft obstacle of 3,100 ft. The tip tank STC specified increasing the 3,650-lb takeoff distance values by 11%, which resulted in a ground roll distance of 2,190 ft and distance to clear a 50-ft obstacle of 3,441 ft. On July 26, 2017, about 12