WPR21LA166

During a night cross-country flight in visual meteorological conditions, the pilot made a precautionary landing due to a failure of the airplane’s engine tachometer. The audio from an airframe-mounted camera captured the pilot’s post-flight inspection comment that the tachometer cable housing appeared to be intact, and subsequent departure on the accident flight. Shortly after takeoff, the pilot deviated left of the runway heading before entering a right turn, away from an on-course heading toward the destination airport. The departure airport was located in a sparsely populated valley with rising terrain on all sides, and the airport’s chart supplement indicated that a 479-ft hill existed about 1.4 nautical miles north of the departure end of the runway. Sound spectrum analysis of the video revealed that the engine rpm decreased slightly, and the video showed an increase in the airplane’s bank angle. There was no indication on the camera of any distress or malfunction. The increased bank angle of the airplane, along with the airplane’s descent and impact with terrain was consistent with an incipient loss of control. Examination of the airframe and engine revealed no evidence of additional mechanical failure or malfunction that would have precluded normal operation. Review of the pilot’s logbook indicated 10.1 hours of night experience and that his most recent night flight before the accident flight was over 90 days before the accident. The lack of cultural lighting in the vicinity of the airport would have provided few visual cues to help the pilot maintain attitude orientation. In addition, the pilot’s decision to fly the airplane without a functioning tachometer may have served as an operational distraction after takeoff. Given the lack of mechanical anomalies, the departure into impoverished lighting conditions, the pilot’s lack of recent night flight experience, and the descending turn into terrain, the circumstances of the accident are consistent with a loss of control shortly after takeoff as a result of the pilot’s spatial disorientation.

At the time of the accident, the airplane’s tachometer time indicated 660.88 hours. Review of the airplane’s maintenance records indicated that a 100-hr engine inspection was performed on March 07, 2021, and the airframe annual inspection was performed on March 28, 2021. Both the airframe and engine logbooks indicated that the inspections were completed at a tachometer time indicated 652.12 hours and a Hobbs meter time of 315.8 hours. The empty weight of the airplane was 1,016 lbs and its maximum gross weight was 1,450 lbs. The combined pilot and passenger weight was 315 lbs. The airplane departed SEZ with full fuel and landed at CMR about 45 minutes later. At the time of departure from the accident airport, about 90 lbs of fuel remained onboard. Aircraft performance calculations derived using the atmospheric conditions about the time of the accident an airplane gross weight of 1,450 lbs in a retracted flap, full throttle configuration, indicated that the airplane would have required a nearly 1,400 ft ground run and could have established a best rate of climb of 378 ft per minute, and normal climb rate of 350 ft per minute at 73 mph per the manufacturer’s operation manual. The GoPro video indicated that the airplane’s ground run was about 1,450 ft, and the airplane remained airborne for just over 63 seconds before impacting terrain. A review of the airport/facility directory revealed that the airport was located in a valley surrounded by rising terrain. The departure runway was 100 ft wide by 6,000 ft in length. The CMR chart supplement indicated that a 479-ft hill was located about 1.4 nautical miles (nm) north of the departure end of runway 36. The sunset on the evening of the accident was 1902, with nautical twilight about 1959. Moon illumination was minimal, as indicated by the waxing crescent moon, with moonrise at 0802 and moonset at 2235. GoPro recordings of the accident flight revealed a faint horizon to the west, visible outside the pilot’s left door, with minimal cultural lighting in the vicinity of the airport and in the direction of the pilot’s right turn. On April 15, 2021, about 1948 mountain standard time, a Cessna 140A, N2506N, was substantially damaged when it was involved in an accident near Williams, Arizona. The commercial pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to social media posts made by the pilot and passenger, they departed Sedona Airport (SEZ), Sedona, Arizona, with the destination of the Grand Canyon National Park Airport (GCN), Grand Canyon, Arizona. Automatic Dependent Surveillance – Broadcast (ADS-B) data indicated that the airplane departed SEZ to the northwest about 1845. About 41 minutes into the flight, the pilot made a precautionary landing at H.A. Clark Memorial Field Airport (CMR), Williams, Arizona. A GoPro video camera mounted to the airplane captured the pilot’s assertion that the airplane’s enginetachometer had failed and that there was “nothing really wrong with the way the airplane is flying.” After landing at CMR, the pilot visually inspected the cable, which was determined to be intact, and subsequently departed on the accident flight. Sound spectrum analysis of the GoPro video indicated that the pilot performed an engine run-up about 1944:49. About 1947:16, engine power was applied for takeoff, and the airplane began flying about 30 seconds later. GoPro video revealed that, during the takeoff climb, the airplane drifted left of the departure runway 36 and paralleled the runway before reaching the departure end of the runway. Sound spectrum analysis confirmed that the engine was operating about 2,448 rpm during the initial climb. About 1948:24, the pilot initiated a turn to the right. A direct track from CMR to GCN would have required a near straight-out departure on a magnetic heading of 353o (about 5o left of the runway heading). About 1948:31, the engine speed decreased to 2,198 rpm. The airplane remained in a right bank and the engine power remained around 2,198 rpm when the airplane impacted terrain about 1948:43. At 1935, CMR reported wind from 280° at 6 knots, 10 statute miles visibility, sky clear, temperature 43°F, dew point temperature of -2°F, and an altimeter setting of 30.01 inches of mercury. The pressure altitude was 6,548 ft and the density altitude was 7,038 ft. Review of the pilot’s flight logbook indicated that the pilot had flown 7.4 hours in the accident airplane make and model within the 90 days before the accident, The pilot had 10.1 hours of night flying experience, but he had not logged night flight time within the 90 days before the accident. The pilot’s logbook indicated that his most recent night flight was conducted on October 29, 2020. The airport elevation was 6,690 ft mean sea level (msl) and the terrain elevation at the accident site was 6,625 ft msl. The wreckage was located about 1,440 ft northeast of the departure end of the runway. Examination of the wreckage revealed that the impact damage was more pronounced on the right side of the airplane. The engine and the cockpit floorboards were displaced upward and aft. The main landing gear were bent aft, rotating the landing gear box forward about 90o. Both wings remained attached to the upper fuselage and exhibited leading edge damage that continued aft to the spar. The cabin sustained occupiable space encroachment. Flight control cable continuity was established between the flight control surfaces and the cockpit controls. Rudder, elevator, and pitch trim cables remained complete and attached. The flap cable remained attached to the flap handle, but the handle position could not be determined due to impact damage. The elevator trim position could not be determined due to impact damage sustained to the trim wheel, but the control cable chain remained intact in the cockpit and in position on the trim actuator. The engine tachometer drive cable wasfound separated inside the housing at the locking sleeve. About one inch of the tachometer drive shaft cable remained attached to the tachometer drive assembly. The tachometer drive rotated freely when the propeller/crankshaft was rotated by hand. The tachometer drive shaft revealed signs of rotational overload. The engine examination revealed no additional evidence of a mechanical failure or malfunction that would have precluded normal operation.