Cessna 177RG N2591V accident near Livermore, California

Probable cause

The total loss of engine power due to an inadequately maintained fuel injection servo.

NTSB analysis

About 30 minutes after takeoff on a cross-country flight, the pilot noticed an increase in engine exhaust gas temperatures (EGTs) for all cylinders. The engine then briefly “stuttered,” and he decided to divert to an airport en route for a precautionary landing. The EGTs then returned to normal, and he decided to continue to the original destination. However, during the landing approach, the EGTs again began to rise; the engine lost all power; and the airplane landed short of the runway and struck approach lights, which resulted in substantial damage to the left wing and stabilator.

Data recorded by the airplane’s engine monitor showed the EGT increases that were reported by the pilot. Disassembly of the fuel injection servo revealed significant internal corrosion and corrosion deposits along with evidence of water ingestion. The corrosion deposits likely resulted in a partial blockage (restriction) of fuel to the cylinders, which manifested itself as a lean fuel mixture. This lean mixture was consistent with the observed increase in EGTs. During the final approach, the blockage likely became severe enough to result in the total loss of power.

The fuel injection servo manufacturer recommends by service bulletin that the unit should be overhauled either every 12 years or at the time of engine overhaul. The unit had last been overhauled 23 years before the accident, and it was not overhauled at the last engine overhaul 10 years before the accident. Additionally, the service bulletin stated that the unit should be overhauled in the event of water contamination. The unit had clearly ingested water at some point during its life, although it could not be determined when this occurred.

Text from the NTSB. Open the NTSB docket for WPR22LA287 for the full record.