Accident Overview
On May 24, 2023, at about 0940 mountain standard time, a Cessna 177B, registration N34713, was substantially damaged when it struck terrain near Tucson, Arizona. The pilot sustained serious injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Pilot's Account
The pilot reported that the accident flight was the first following an engine overhaul. After boarding at Tucson International Airport (TUS), he performed ground operational tests as part of the engine break-in procedure. The final step required a 5-second full-power application, during which the airplane's tires rolled beyond the wheel chocks. The engine was shut down, and the test was not repeated. The pilot then restarted the engine, contacted the tower controller, and requested a visual flight rules departure to conduct in-flight break-in. During the initial climb, the airplane did not maintain the expected climb profile. Over the departure end of the runway, the pilot informed the tower controller that he needed to make a 180° turn and return. The controller cleared the request. As the pilot initiated a left turn, the airplane descended and impacted the ground.
Accident Site and Damage
The accident site was approximately 2,085 feet east of the departure end of runway 11L, on a magnetic heading of 109°. Postaccident photographs indicated the left wing struck the ground in a nose-low attitude. The outboard left wing separated at the aileron/flap junction, with crushing signatures from the bottom extending to the leading edge. Damage to the right wing's outboard leading edge and aileron was consistent with a postimpact cartwheel motion. The empennage separated aft of the baggage compartment. The cabin roof remained attached to the right wing and inboard left wing. The instrument panel, engine, and nose strut were observed as a single unit.
Engine Examination
Postaccident examination of the engine revealed no evidence of preimpact mechanical malfunctions. The induction and exhaust systems showed no preimpact issues. The magnetos were securely attached, and ignition harnesses were secure. Magneto-to-engine timing could not be verified due to flywheel destruction, but both magnetos were timed within 1° of each other. The right magneto produced spark normally; the left magneto's impulse coupler was nonfunctional, with the pawl not engaging the pin.
Fuel System Findings
The engine logbook showed all flexible hoses were replaced before the break-in. Fuel system inspection from the wing tanks to the gascolator revealed no anomalies. A small amount of fuel drained from the strainer tested negative for water. Compressed air introduced to the fuel pick-up lines showed no obstructions. A small amount of dirt was found in the fuel strainer bowl. The fuel flow transducer exhibited a restriction that limited fuel delivery to the carburetor. Disassembly of the Electronics International Inc. FT-60 transducer revealed a polymer strip (5/8" x 1/4") inside the fuel entry port bore. The carburetor was unremarkable.
Engine Monitor Data
The airplane was equipped with an Electronics International Inc. CGR-30P engine monitor. Recorded data showed that at 09:36:03, engine rpm increased to 1,550 and reached a maximum of 2,700 at 09:36:13, corresponding to 84% horsepower. During initial climb, horsepower decreased to 75%. Exhaust gas temperatures were high, and cylinder head temperature exceeded the maximum limitation of 500°F. Maximum fuel flow reached 16.9 gallons per hour then decreased variably. The airplane's maximum recorded altitude was 101 feet above ground level (agl). The last data point at 09:38:16 showed an altitude of 96 feet agl; no further data were recorded.