History of Flight
On September 9, 2016, about 0700 mountain standard time, a Cessna 310N, registration N126P, struck a refuse transfer trailer shortly after takeoff from Wickenburg Municipal Airport, Wickenburg, Arizona. The airline transport pilot and three passengers sustained serious injuries. The airplane, a twin-engine model, was registered to and operated by the pilot under 14 Code of Federal Regulations Part 91 for a personal flight departing to Payson, Arizona. Visual meteorological conditions prevailed; no flight plan was filed.
Witnesses reported observing the airplane takeoff from runway 23 and veer to the right of the centerline shortly after rotation. After reaching an altitude of about 75 feet above ground level, the airplane did not climb further. It crossed the runway verge toward an adjacent industrial park. A witness stated that a few seconds later, the airplane rolled almost 90 degrees to the right, and the right wing struck the refuse trailer. The right wing separated from the airframe, and the main fuselage came to rest about 75 feet downrange within the City Sanitation Department, about 2,200 feet beyond the runway departure threshold and about 30 degrees right of the centerline. The pilot and passengers were treated at the scene; due to their injuries, they could not recall the accident circumstances.
Personnel Information
The pilot held an airline transport pilot certificate with multiengine land ratings, a single-engine land instructor rating, and type ratings for the B-727, B-757, B-767, DC-3, and N-265. He also held an airframe and powerplant mechanic certificate with inspection authorization. His last flight review was in March 2014, and he reported practicing single-engine procedures in the accident airplane in July 2016.
Aircraft Information
The airplane was manufactured in 1968 and had been owned and maintained by the pilot since 1985. It was equipped with two six-cylinder, fuel-injected Continental Motors IO-470 series engines. The right engine was overhauled and installed in 1986, accruing 690.9 flight hours at the last annual inspection on July 6, 2016. The left engine was overhauled and installed in a Cessna 310N in 1978, then removed and installed on the accident airplane in 1988, accruing 1,268.7 flight hours at the last annual inspection.
Meteorological Information
Area winds were from the northwest at 5 knots. The altimeter setting was 29.93 inches of mercury, temperature 25°C, dew point 16°C, and density altitude about 4,200 feet.
Medical and Pathological Information
Toxicological tests on the pilot's specimens, performed by the FAA Bioaeronautical Sciences Research Laboratory, were negative for ethanol and all screened drugs except Etomidate, an anesthetic agent often used in emergency treatment.
Examination Findings
Examination of the engine control quadrant at the accident site showed both mixture controls in the full rich position, propeller controls 1 inch short of full forward, and throttle controls bent to the right and over the quadrant about midrange. Both the flap actuator and landing gear assemblies were in positions consistent with retraction.
Left Engine: The left engine partially separated from the firewall. Both propeller blades exhibited a 15-degree bend about 12 inches from the hub, with nicks and chordwise scratches. Fuel lines and controls were intact; spark plug electrodes showed normal wear. Magneto timing and compression were correct. No mechanical anomalies were found in the fuel manifold, pump, or metering unit. Debris (dried grease and ferrous material) was on the spring side of the mixture control cam.
Right Engine: The right engine sustained similar impact damage. Both propeller blades had detached and were straight, with no rotation damage signatures but with blue streak marks matching the trailer paint. No mechanical anomalies were found except: the throttle body inlet screen had lint covering about 1/8 of its surface; the fuel injector nozzle for cylinder 3 was partially occluded with a solid glaze; no fuel was in the manifold or fuel line. A clear gelatinous substance completely blocked the fuel flow transducer inlet port (metering orifice). After exposure to air, the substance hardened to a texture similar to RTV silicone. Similar material was found in the fuel manifold valve cavity. The material was identified as silicone (polydimethylsiloxane).
Fuel System: The airplane had 20-gallon auxiliary fuel tanks in each wing and 50-gallon main tip tanks. Fuel system filters included a 104-micron strainer, a 210-micron metering unit filter, and a 210-micron manifold valve filter. A Shadin 910502 fuel flow indicating system was installed in 1982 with a FloScan 201 transducer (installed 1995). The transducer inlet metering orifice was about 0.115 inches in diameter. No debris was observed in the wing tip or auxiliary tanks. Airframe and engine fuel lines showed no traces of RTV sealant; lines in the engine compartment were stiff and showed chafing. The owner stated he never used RTV silicone on fuel system components.
Performance: The pilot reported a takeoff weight of 4,900 pounds. The owner's manual provided normal takeoff speeds and single-engine climb performance data. At the accident conditions, single-engine takeoff distance to clear a 50-foot obstacle was calculated to be about 6,200 feet at 4,900 pounds, and beyond the graph's 7,000-foot scale at higher weights.