Cessna T-310P Accident Near Ogden, Utah (N5805M)

Flight Details and Accident Sequence On January 15, 2020, at approximately 1511 mountain standard time, a Cessna T-310P airplane, registration N5805M, was involved in a fatal accident near Ogden, Utah. The aircraft was operating under 14 Code of Federal Regulations Part 91 as a local flight. The pilot, who was the sole occupant, was fatally injured. According to automatic dependent surveillance-broadcast (ADS-B) data, the aircraft departed northbound from Skypark Airport (BTF) in Bountiful, Utah, and initiated an approach to Ogden-Hinckley Airport (OGD) a few minutes later. OGD is located approximately 22 miles north of BTF. During the flight, the aircraft climbed to an altitude of about 5,200 feet mean sea level and reached a maximum airspeed of 145 mph. It subsequently experienced a series of short descents and climbs, losing airspeed during each climb and partially regaining it during descents. The final recorded airspeed was 79 mph, approximately one mile south of OGD. Multiple witnesses observed the aircraft flying northbound parallel to Interstate 15, noting its slow speed. One witness, located about 1.5 miles south of OGD, described the engine sound as “popping” and suspected an engine restart attempt. The aircraft was observed at an altitude of 150 to 200 feet above the ground with landing gear and flaps extended. The witness noted the aircraft was “crabbing” to the left and struggling to maintain altitude, with the tail section appearing lower than normal. The left wing dropped, the aircraft momentarily stabilized, and then banked further left before crossing the interstate, where the nose dropped and the aircraft was lost from sight. A dash camera captured the aircraft at approximately 100 feet above the ground with wings level and gear extended. A doorbell surveillance camera recorded the aircraft in a nose-down, left-wing-down attitude at about 50 feet above the ground prior to impact, with a fire explosion visible from other neighborhood cameras. The pilot had extensive experience with the aircraft model and had previously landed with one working engine. However, the pilot had previously expressed reluctance to declare in-flight emergencies due to the associated paperwork. The aircraft had been at BTF for maintenance to repair a fuel leak on the left wing tip fuel tank. Text communications between the maintenance facility and the pilot on January 10, 14, and 15, 2020, included photos showing blue fuel staining on the lower side of the left-wing tip fuel tank. On January 15, the maintenance facility confirmed that “the leak checks appear good.” The pilot picked up the aircraft on the day of the accident without refueling, as confirmed by fueling records. Maintenance records indicated that the left main tank was repaired with a new gasket and O-ring in the fuel outlet fitting, followed by a leak check with 2.5 gallons of fuel. The first point of contact was the southwest corner of a townhome roof, with the left fuel tank embedded in the roof. The debris field extended 135 feet along a heading of 210° magnetic. The main wreckage came to rest upright on a rock retaining wall, with the cabin area mostly consumed by fire. The fuel selector valves were found in the “OFF” position, and the left propeller was not feathered at impact. One left propeller blade showed rotational scoring and bending, while the right propeller blades exhibited rotational scoring and impact damage. Post-accident examination found no pre-accident mechanical malfunctions that would have precluded normal operation. The pilot checked in with OGD air traffic control when approximately 9 miles south of the airport, reporting inbound from BTF and requesting a full-stop landing. The controller cleared the pilot for the landing on runway 35 when the aircraft was 2 miles out. The pilot read back the instruction, and communications were reported as normal. The controller observed the aircraft initiate a steep left banking turn, followed by a steep right bank while losing altitude, before losing sight of the aircraft. A short inaudible sound was heard over the radio, with no further communication from the pilot. Performance data indicated that with one engine lost, the minimum single-engine control speed was 90 mph indicated airspeed, and the safe single-engine speed was 105 mph. The owner’s manual recommended an approach speed of 113 mph with excessive altitude for a single-engine approach. If both engines were lost, the maximum glide was one mile for every 500 feet of altitude at approximately 120 mph. A performance study showed the aircraft slowed from over 140 mph to under 90 mph and was below the glide slope for runway 35, slowing below its aerodynamic stall speeds. Sound spectrum analysis of doorbell camera audio suggested at least one propeller was operating at approximately 2,430 RPM as the aircraft approached the camera, with potential acoustic beating indicating both propellers may have been operating at similar blade passage frequencies.