What happened
On the morning of 20 November 2011, a Jihlavan KP 2U-Rapid, registration ZU-GDH, departed Tedderfield aerodrome for a private flight to Lekoa Game Lodge. Approximately three minutes after takeoff, while the aircraft was climbing, the engine failed. The pilot attempted to restart the engine but was unsuccessful.
At an altitude of roughly 950 feet, the pilot maintained a speed of approximately 65 mph and searched for a suitable landing site. After passing over an initial field that was deemed unsuitable due to excessive speed, the pilot targeted a second ploughed field located about 5 nm southeast of the aerodrome. The pilot chose to keep the landing gear retracted to prevent a potential nose-over on the soft ground. The aircraft touched down at approximately 40 mph and came to a stop 35 metres from the initial contact point. There were no injuries to the two occupants, who evacuated the aircraft unassisted.
The investigation
SACAA AIID investigators examined the engine and the components involved in the failure. The investigation focused on the lubrication system and the history of the engine's maintenance. It was discovered that during a non-routine repair in 2007, three external oil pipes had been replaced with stainless steel industrial braided hydraulic compression pipes manufactured by a local vendor, rather than using Rotax-certified parts.
Testing of the specific pipe supplying oil from the external reservoir to the oil cooler revealed that the component had perished beneath the crimp lug. This failure allowed air to enter the lubrication system, which led to the engine seizure. The investigation noted that the damaged area was concealed by the stainless steel braiding, making it impossible to detect during standard visual inspections.
Findings
- The primary cause of the incident was an engine seizure during flight.
- A perished oil supply pipe allowed air to be drawn into the lubrication system, causing an insufficient oil supply to critical engine components.
- The replacement oil pipes were non-Rotax certified industrial components.
- The failure point was located in a concealed area of the pipe, rendering it undetectable during routine annual inspections.
- The aircraft had been operating with these non-standard pipes for approximately 444.7 hours over a period of four and a half years.