N1839R

On July 9, 2023, about 1500 Pacific daylight time, a Cessna A185F, N1839R, was substantially damaged when it was involved in an accident near La Mesa, California. The pilot and passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot reported that he departed Montgomery-Gibbs Executive Airport (MYF), San Diego, California, about 1450, to relocate the airplane to Brown Field Municipal Airport (SDM), San Diego. The pilot calculated that he would require about 5 gallons of fuel from the 16 gallons of fuel remaining in both tanks, according to the fuel gauges. The pilot stated that he did not refuel the tanks before departure as he intended to do so at a different local airport. The fuel tanks were filled about one month before the accident flight. He further reported that he did not visually confirm the level of the fuel within each tank during his preflight. Based on the 74-gallon total fuel capacity, 16 gallons of total fuel would equate to about less than a ¼ tank on each fuel gauge.

The pilot reported that the engine had lost all power while in cruise flight about 1,700 ft msl. The engine momentarily regained some power for about ten seconds, but it then lost all power again. The pilot completed an emergency engine failure checklist and prepared the aircraft for an off-airport landing on a nearby road in a residential area.

The right wing hit a powerline during the approach to landing. The aircraft subsequently crash-landed in a parking lot, collided with a fence and dense vegetation, and eventually came to a stop in a ravine. The fuselage and both wings of the aircraft were substantially damaged. The pilot noted that he turned off the master switch as he saw fuel leaking from a breached section of the left wing.

Postaccident examination of the airplane and engine did not reveal any preimpact mechanical anomalies. The fuel system was traced from each wing tank to the fuel servo at the engine through the fuel selector, which rotated normally and was unobstructed. The fuel lines that had not been damaged from impact or removed to transport the airplane were secure.

Mechanical continuity was established throughout the rotating group, valvetrain and accessory section as the crankshaft was manually rotated at the propeller by hand. Thumb compression was achieved at all six cylinders and the valves displayed normal lift when the crankshaft was rotated. Examination of the cylinders’ combustion chamber interior components using a lighted borescope revealed normal piston face and valve signatures, and no indications of catastrophic engine failure. Review of a carburetor icing chart revealed that the airplane was not susceptible to carburetor icing at cruise power for the prevailing temperature and dew point.

A review of the downloaded data indicates that the exhaust gas tempertures (EGTs) were operating around 1340° F in all cylinders. At 14:58:39, about 2 minutes before the power loss event, the EGTs increased slightly and then dropped to about 900° F in all cylinders. At 14:58:54, about a minute before the end of the flight, all EGTs increased again, peaking about 1300° F before dropping off to about 200° F.