Synopsis
On 9 January 2019 at approximately 0500Z, a pilot and his dog departed from a private farm, Mahohomal, in the Northern Cape Province, bound for Wonderboom Airport (FAWB) in Gauteng. The flight was conducted under Part 91 of the Civil Aviation Regulations. About one hour into the flight, the pilot heard a strange noise from the engine, followed by high vibrations. The engine lost power and subsequently stopped. White smoke was seen emanating from the engine compartment. The pilot executed a forced landing on an open field in Phephane farm, near Morokweng, North West Province. The landing gear was lowered, and the aircraft touched down in bushy terrain. The landing gears dug into soft sand and broke off; the aircraft skidded on its underbelly for approximately 15 metres before coming to rest. The pilot and his dog sustained no injuries. The aircraft suffered substantial damage to the propeller, landing gear, wings, fuselage, and tail section.
Factual Information
On 9 January 2019 at about 0558Z, the aircraft's Artex 1000 ELT transmitted automatically upon coming to rest in an isolated area. The Aeronautical Rescue Coordination Centre (ARCC) contacted the pilot, who confirmed no injuries and provided GPS coordinates via SMS. Local police initially searched about 80 km northwest of the actual site due to a coordinate discrepancy. A helicopter operator located the pilot at approximately 1200Z near the accident site (S26°18'50.8" E023°52'12.9").
The pilot reported the surface wind was 30°/5 kt, temperature 25°C, and visibility good. He stated he had checked the engine oil prior to the flight, noting the level at the 9 US QT mark, and had not observed any abnormalities in oil temperature or pressure during flight. He did not record oil uplifts in the flight folio. The aircraft's last annual inspection was on 3 August 2018 at 2080.90 airframe hours; the engine had 28.90 hours since that inspection.
Additional Information
A maintenance organisation conducted an engine strip-down and reported that the #4 and #5 connecting rod bearings had seized in the crankshaft. Main bearings showed wear indicating incipient failure. No oil was found in the oil coolers or oil hoses, but some oil was present in the constant speed unit. No loose, damaged, or missing oil system components were found except for damage to the engine crankcase caused during the failure.
Lycoming confirmed that the main and connecting rod bearings used during the engine overhaul (completed January 2016) had correct part numbers. Lycoming Service Bulletin 632B and FAA Airworthiness Directive 2017-16-11, issued in August 2017, addressed connecting rod failures; however, no evidence was found that these were carried out on the aircraft. The overhauling AMO stated that the affected bushes were not shipped from Lycoming during the specified period.
Service Bulletin 480 mandates oil and filter changes every 50 hours or four months. The first oil change after overhaul was done on 8 June 2017 at 85.5 hours (one year and four months after overhaul). The next on 3 August 2018 at 82.2 hours (one year and two months later). The engine failed on 9 January 2019 at 28.9 hours (five months and six days after the last oil change).
Findings
The pilot held a private pilot licence issued 2 February 2018, with 1862.2 total hours and 434 on type. His medical certificate had restrictions for hypertension, hypothyroidism, and contact lenses.
The aircraft's last annual inspection was 3 August 2018 at 2080.90 airframe hours; it flew 28.90 hours since. The Lycoming IO-540-K1G5D engine had 2218.20 total hours, overhauled at 2021.6 hours, operated 196.60 hours since overhaul.
No evidence confirmed compliance with SB 632B/AD 2017-16-11; however, the affected parts were not from the suspect shipment. The pilot did not record oil uplifts in the flight folio.