WPR16FA152

The pilot's failure to maintain control during takeoff initial climb for reasons that could not be determined because a postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation.

The airline transport pilot was departing on a cross-country flight in the multi-engine airplane. Shortly after takeoff and during the initial climb, witnesses observed the airplane drift to the left and then descend and collide with terrain off the left side of the departure runway. The airplane came to rest about 3,775 ft from where the takeoff run commenced, and about 300 ft south of the extended centerline of the runway. The majority of the airplane was consumed by postcrash fire. The airplane's estimated ground speed during the last 5 seconds of flight was about 70 knots. It could not be determined whether this speed was above, near, or below the manufacturer's best angle, best rate, or recommended climb speed. The investigation revealed that both engines fuel system had been modified by the removal of the pressure carburetors and replaced with continuous fuel flow injection systems. This modification would require a re-identification on the engine data plate, which was not accomplished, and field approval documentation for the alteration.  A search of the airplane's FAA airworthiness file found no records regarding the alteration. Documentation relative to the airplane's revised performance data, which would have been published subsequent to the approval of the fuel injection system modification was also not located in order to determine the effect of airplane performance at the calculated 5,483 foot density altitude at the time of the accident. The propeller strikes found along the debris path and the rotational damage to the blades of both propellers indicated that both engines were developing power at impact. A postaccident examination of the airframe and engine did not reveal any evidence of mechanical anomalies that would have precluded normal operation. The investigation could not determine the reason for the pilot's failure to maintain control of the airplane on takeoff/initial climb.

Engine Modification According to a Federal Aviation Administration airworthiness inspector assigned to this accident who examined both engines at the accident site, the inspector reported that both O-470M engine's fuel system had been modified by removal of OEM Bendix PSD-5C pressure carburetors, and installation of TCM continuous flow fuel injection systems. Engine TCDS E273 allows this mod under note 6, [which] requires re-marking the data plates as O-470M(CI). This re-identification was not found on the data plates of either engine. The Cessna 310B TCDS 3A10 shows only the O-470M as the only approved engine and does not include the O-470M(CI). The Continental Continuous Flow fuel injection system Drawing Eq. No. 5580 requires that the engine driven pump be replaced with one of a higher pressure rating than the OEM Bendix pressure carburetor requires. This would necessitate that the airframe mounted fuel boost pumps would require replacement with later model pumps that delivered a higher pressure rating required for later model C310 aircraft equipped with TCM continuous flow fuel Injection. This aircraft would require a 337 field approval for such conversion and installation of O-470(CI) continuous flow engines in this aircraft. Records revealed no such Field Approval 337 forms on file for such an alteration. Additionally, as there were no maintenance records located during the investigation, it could not be determined when or by whom the engine modifications were performed. Performance Data During the investigation, it was reported by the FAA's Aircraft Certification Office, Atlanta, Georgia, that after an exhaustive search for documentation relative to the airplane's revised performance data, which would have been published subsequent to the approval of the fuel injection system modification, that documentation could not be located. At 1655, the weather reporting facility located at O22 indicated wind from 290° at 7 knots, visibility 10 statute miles, temperature 40°C, dew point 3°C, and an altimeter setting of 29.92 inches of mercury. The airport elevation for O22 is 2,121 ft mean sea level. The density altitude at the time of the accident was calculated to be 5,483 ft. The Tuolumne County Office of the Coroner, Sonora, California, conducted an autopsy on the pilot. The medical examiner determined that the cause of death was asphyxia due to inhalation of smoke and fumes. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology tests on the pilot. According to the toxicology report, a 34% concentration of carbon monoxide was detected in blood, and 1.96 us/ml cyanide was detected in blood. No ethanol or drugs were detected by the testing. Carbon monoxide and cyanide in the blood can result from inhalation of smoke and fumes during a fire. The pilot held an airline transport pilot certificate with airplane single-engine land, multi-engine land, and single-engine sea ratings, as well as a flight instructor certificate with single-engine, multi-engine, and instrument airplane ratings. He also held type ratings for CE-500, CE-560, and SA-227 airplanes. The pilot's personal flight logbooks were not located during the investigation. At the time of the accident, the pilot was employed as a pilot for an on-demand Part 91 Subpart K fractional ownership company. The pilot was issued a first-class airman medical certificate on May 18, 2016, with no limitations noted. On the application for this medical certificate, the pilot reported a total flight time of 12,000 hours of which 200 hours were accumulated in the previous 6 months. The five-seat, low-wing, retractable-gear airplane, serial number 35705, was manufactured in 1958. It was powered by two fuel-injected Continental IO-470 engines, serial numbers 50164-5-M (right), and 51603-7-M (left), each equipped with a McCauley three-bladed, constant-speed propeller. During the investigation, the aircraft, engine, and propeller maintenance records were not located. A review of FAA documents found that, according to the airplane's type certificate data sheet, the only engine approved to be installed on the aircraft was a Continental O-470-M engine. The type certificate data sheet also listed the approved propellers as either Hartzell HC82XF-2 or HC-A2XF-2. The FAA supplemental type certificate (STC) database was searched for STCs that would allow for the installation of fuel injected IO-470 engines and/or McCauley propellers on the airplane. The search revealed STC SA2-1578 that was issued to Bendix Corporation for the installation of Teledyne Continental Motors O-470-BI or O-470-MI engines modified for fuel injection on Cessna 310, 310A, 310B, and 310C airplanes. The search also revealed STC SE2-1577 that was issued to Bendix Corporation for the installation of Bendix RS-5BD1 or RSA- 5AD1 fuel injection systems on Continental O-470-B, O-470-M, O-470-H, and O-470-N engines. Additionally, a search of the airplane's FAA airworthiness file found no records regarding the installation of these STCs on the airplane. Further, FAA Form 337 for the installation of these STCs as they are a major repair, were not found during the investigation. Also, an STC for the installation of the McCauley propellers was not located. The airplane came to rest about 3,775 ft from where the takeoff run commenced, and about 300 ft south of the extended centerline of the runway The initial impact point was in a gravel area between the main ramp and a helicopter ramp. The wreckage path led from the initial impact point on a magnetic heading of 158° to the main wreckage, which was located just before the paved surface of the helicopter ramp. Two sets of slash marks were noted in the wreckage path consistent with strikes by the left and right propellers. The fuselage came to rest on a magnetic heading of 194°. As the airplane came to rest, the right engine nacelle stuck the rear of a parked fuel truck. Postimpact fire consumed a majority of the fuselage and the wings inboard of the engine nacelles. The fuselage was consumed from the forward cabin bulkhead to aft of the cargo compartment. The empennage exhibited some heat damage but remained intact with minimal impact damage. The outboard section of the right wing had minimal damage with one area of crushing of the leading edge about 2 ft inboard from the tip. The left wing exhibited upward crushing from the tip inboard to the nacelle. The left and right fuel tip tanks both separated from the wings during the impact sequence. The left engine remained attached to its wing by a portion of the engine mount. The throttle, propeller, and mixture cable rod ends were observed attached to their respective control levers. The left propeller hub had separated from the crankshaft flange and came to rest forward of the main wreckage. All three blades remained attached to the hub and exhibited chordwise scratches, gouging and curling. The right engine remained attached to the wing at the engine mounts. The right propeller remained attached to the crankshaft flange. All three blades remained attached to the hub and exhibited gouging, chordwise scratches, and curling. All the flight controls were attached to their respective attach points. Flight control continuity was established from the flight control surfaces to the cockpit with the exception of a 1-ft section of unidentified cable that was embedded in molten metal from the postimpact fire. The flaps were found in the fully retracted position. The landing gear was found in the retracted position. None of the cockpit instruments could be documented because of thermal damage. All engine controls were full forward in the cockpit and bent to the left Both fuel selector valves were noted to be in the "main tank" position. The glass containers of both fuel strainers were intact; the fuel strainer screens exhibited thermal damage but appeared to be clea