Occurrence
On 23 May 2025 at 1301Z, a Piper PA-28-140 aircraft (registration ZS-FGU) conducting a training flight under Part 141 experienced an engine failure while en route from George Airport (FAGG) to Port Alfred Airport (FAPA). The student pilot performed a forced landing on a field 6 nm southwest of FAPA, at coordinates 33°35′36.52″ S 026°45′46.85″ E, elevation 423 ft. The aircraft sustained minor damage; the pilot was not injured.
Flight History
The flight departed FAPA at approximately 1100Z for an hour-building flight to FAGG and intended return. After landing at FAGG, the pilot checked the engine oil level and found it below four quarts. An aircraft maintenance engineer provided six cans of AeroShell W100 oil. The pilot added one quart, then another, bringing the dipstick reading to about five quarts. No external oil leaks were found. The flight departed for FAPA with all engine parameters normal.
Abeam Plettenberg Bay, oil pressure decayed to 50–60 psi; oil temperature remained stable. The pilot contacted the maintenance organization at FAPA, which advised continuing. Upon entering the Chief Dawid Stuurman International Airport Special Rules Area abeam Jeffreys Bay, oil pressure dropped to 20–30 psi (yellow arc); oil temperature remained in the green arc. Noticing abnormal engine noise and vibration, the pilot suspected a gauge malfunction per the Pilot's Operating Handbook (POH). Approximately 8 nm southwest of Nanaga, oil pressure decayed to nearly zero; oil temperature remained normal.
About 3 nm northeast of Kenton-on-Sea, the engine ran rough, vibrated, and lost power. The pilot declared a MAYDAY on 122.0 MHz, attempted an unsuccessful engine restart, and noted smoke and a burning smell before landing on a field.
Engine Teardown Inspection
The Lycoming O-320-E2A engine (serial L-15582-27A) was removed and disassembled. Findings included:
- Connecting rod (conrod) of Cylinder 1 had punctured the crankcase.
- External impact marks above pushrod tubes of Cylinder 4.
- Conrod 4 journal showed clear signs of oil starvation and appeared to have failed first, breaching the oil sump.
- Conrod 1 failed subsequently.
- The oil pump contained a significant quantity of metal filings that restricted oil supply; after debris removal, the pump was mechanically serviceable.
Contributing Factors
The investigation identified:
- Suspected insufficient oil quantity at initial departure from Port Alfred.
- In-flight metal filings from Cylinder 4 led to contamination and progressive oil pump failure.
- No external oil leaks were observed, confirming oil consumption.
- Gradual pressure decline did not initially trigger emergency actions.
- Oil pump seizure from metal contamination marked the point of no recovery.
Conclusions
The engine failure was caused by progressive oil starvation, compounded by an inoperative oil pump due to metallic debris contamination. The root cause appeared to be an initial oil underfill, as only two of the six oil cans were used, and the engine consumed oil at a rate exceeding the Lycoming maximum of 1 quart per hour over the 2-hour flight.