N2085QCessna 177RG · 1974

On September 12, 2021, about 1609 mountain standard time, a Cessna 177RG, N2085Q, was substantially damaged when it was involved in an accident near Lake Havasu Airport, Lake Havasu, Arizona. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot was planning to make a cross-country flight to Reno, Nevada, in the days after the accident, and the purpose of the accident flight was to refuel for the flight to Reno. The airplane was based at Eagle Airpark, Bullhead City, Arizona, and the pilot performed maintenance there earlier in the day, including replacing the bushings on the nosewheel because the airplane had been experiencing a vibration during takeoff and landing. The airplane departed about 1530 and landed at Lake Havasu about 1545. The pilot then purchased 24.8 gallons of fuel at the self-serve fuel tank. According to his wife, the pilot had planned to top off the fuel tanks to full.

Video and audio recordings and Federal Aviation Administration (FAA) automatic dependent surveillance-broadcast (ADS-B) data showed that the pilot taxied the airplane to runway 14, performed a run-up, and departed about 1608. Witnesses reported that the airplane traveled down the runway at a slow groundspeed and noted that the engine sounded abnormal, as if it were producing partial power. The airplane veered to the right of the centerline and ascended 100 to 150 ft above ground level (see figure 1). ADS-B data showed that the airplane accelerated down the runway at airspeeds up to 65 knots.

Figure 1: Security camera video showing initial right veer

The video showed the airplane pitch to a nose-high attitude and banked to the left (see figure 2). Witnesses observed the airplane’s wingspan turn nearly perpendicular to the horizon and then stall with the left wing dropping toward terrain.

Figure 2: Security camera video of left bank

At an undetermined time during the takeoff, the pilot stated, on the airport common frequency, “Lake Havasu traffic Cardinal 2085Q making a uh” The next recorded transmission, which occurred less than 1 second later, was a high-pitch tone similar to a stall warning horn. The airplane impacted desert terrain about 830 ft from the end of runway 14, and a postcrash fire ensued.

The pilot’s wife stated that he performed most of the airplane’s maintenance and that he flew the airplane regularly after purchasing it in 2013. A review of the pilot’s logbook revealed that the airplane had a total time of 3,487.3 hours and that the engine had accumulated 1,219.4 hours since the time that it was remanufactured at the manufacturer. The logbook indicated that the camshaft and lifters were replaced with new parts in December 2004, 682 hours before the accident. The logbook also indicated that the No. 1 cylinder had been replaced with an overhauled assembly in March 2020, 75.1 hours before the accident. The last recorded oil change was performed at the airplane’s last annual inspection.

To monitor engine component wear rate, the pilot had sent samples of the engine oil for spectrometer analysis multiple times; the most recent of which was September 9, 2021 (3 days before the accident). At that time, the engine had accumulated 1,216.7 hours or 2.7 flight hours. The sample had not been run before the accident occurred; after the accident, the sample showed elevated levels of aluminum, chromium, iron, silicon, and nickel (see figure 3).

Figure 3: Oil analysis report showing six samples, including the one taken 3 days before the accident (Source: BlackStone Laboratories).

The laboratory oil report for the September 2019 sample stated that there were elevated levels of metal and that, if work had not been done recently on the engine, the amount of aluminum, chromium, and iron would indicate piston, ring, and steel wear. The oil report further stated that the amount of chrome indicated “a ring problem.”

The pilot’s wife stated that he performed most of the airplane’s maintenance and that he flew the airplane regularly after purchasing it in 2013. A review of the pilot’s logbook revealed that the airplane had a total time of 3,487.3 hours and that the engine had accumulated 1,219.4 hours since the time that it was remanufactured at the manufacturer. The logbook indicated that the camshaft and lifters were replaced with new parts in December 2004, 682 hours before the accident. The logbook also indicated that the No. 1 cylinder had been replaced with an overhauled assembly in March 2020, 75.1 hours before the accident. The last recorded oil change was performed at the airplane’s last annual inspection.

To monitor engine component wear rate, the pilot had sent samples of the engine oil for spectrometer analysis multiple times; the most recent of which was September 9, 2021 (3 days before the accident). At that time, the engine had accumulated 1,216.7 hours or 2.7 flight hours. The sample had not been run before the accident occurred; after the accident, the sample showed elevated levels of aluminum, chromium, iron, silicon, and nickel (see figure 3).

Figure 3: Oil analysis report showing six samples, including the one taken 3 days before the accident (Source: BlackStone Laboratories).

The laboratory oil report for the September 2019 sample stated that there were elevated levels of metal and that, if work had not been done recently on the engine, the amount of aluminum, chromium, and iron would indicate piston, ring, and steel wear. The oil report further stated that the amount of chrome indicated “a ring problem.”

The accident site was at an elevation of 790 ft mean sea level, and the terrain was composed of dry, soft dirt with sparse brush. The terrain ahead of the accident site was uninhabited and populated with low brush. The wreckage was found distributed over a 200-ft distance on a median magnetic bearing of about 60°. The main wreckage included the airframe and engine, most of which had been consumed by fire. The first identified points of contact consisted of disrupted dirt on the flat desert terrain at the far east-southeast end of the debris field. The markings started as a dirt indentation with shards of red fragments imbedded within the soil, consistent with the left wingtip impacting the ground first. The crater was continuous toward the main wreckage, and the end of the crater had blue/green fragments imbedded (see figure 4). A larger center indentation (referred to in the figure as the middle crater) was found in between the red fragments and the green/blue fragments; this indentation had a large arc-shaped disruption of dirt that was consistent with a rotating propeller blade.

Figure 4: Main wreckage in reference to first identified point of impact.

As part of the postaccident examination, most of the engine and its components were disassembled. The Nos. 1 and 4 top compression piston rings had fractured in multiple locations (see figure 5). All the piston skirts showed evidence of corrosion and wear with light scuffs/grooves oriented from the base to the crowns. Additionally, the piston skirts on all cylinders showed evidence of blow-by, with the No. 3 cylinder exhibiting the least amount of damage.

Figure 5: Fractured rings from the Nos. 1 and 4 pistons.

The National Transportation Safety Board Materials Laboratory examined the No. 1 and No. 4 fractured piston rings. The upper compression piston ring from the No. 1 cylinder had fractured in four locations. All fracture and parting surfaces exhibited iron oxides with high amounts of carbon, lead, and bromine, consistent with exposure to combustion gases from airplane fuel. Extensive wear and smoothing were observed on the fracture and parting surfaces, consistent with the fractures occurring before the accident and continuing to wear during the repetitive actuation of the pistons inside the cylinders. Fracture and wear of the rings could allow blowby of combustion gasses past the piston and oil leakage into the combustion chamber.

Separation of the crankcase halves revealed severe spalling on the faces of all the intake lifters and the No. 3 exhaust lifter; evidence of galling was also noted. The remaining lifters showed evidence of wear with a circular pattern and pitting (see figure 6). The camshaft revealed signatures of excessive wear on the cam lobes, including rounding of the lobes, pitting, and material deformation on the lobes.

Figure 6: Wear signatures on intake lifter faces (top row) and exhaust lifter faces (bottom row).

The lifter on the No. 4 exhaust valve exhibited a tear in the base of the body, consistent with contact with the hydraulic socket; the pushrods did not show evidence of bending. The bearings showed light wear, and the crankshaft had light rotational scoring.