On 9 June 2013, an Australian-registered Cessna 206 aircraft, registration VH-JIA, was extensively damaged in an accident while attempting to land on a beach strip near Bukaua River, Papua New Guinea. The pilot reported that during the landing roll, the nose landing gear fork had failed, allowing the aircraft to dig into the soft sand and flip over.
The Accident Investigation Commission (AIC) of Papua New Guinea was responsible for investigating this accident. As part of its investigation, the AIC requested technical assistance from the Australian Transport Safety Bureau (ATSB), in the metallurgical examination of the failed landing nose fork and the download and analysis of the pilot's navigational GPS unit that was recovered from the accident site. To provide the necessary protections for the GPS information and the findings of the landing gear analysis, the ATSB appointed an Accredited Representative to the investigation in accordance with clause 5.23 of Annex 13 to the Convention on International Civil Aviation (ICAO Annex 13), and initiated an investigation under the Australian Transport Safety Investigation Act 2003.
Landing gear analysis
The characteristics of the nose landing gear fork failure revealed during the ATSB laboratory examination were consistent with fracture occurring from a pre-existing manufacturing condition that predisposed the fork to brittle fracture along the forging seam (parting) lines during conditions of elevated lateral stress (such as sustained during beach or other soft-surface landings). The fracture surfaces showed no evidence of fatigue cracking, stress-corrosion cracking or other progressive failure mechanisms.
Cracking and failure of Cessna nose forks has been an isolated but recurrent problem for Cessna 100- and 200-series aircraft, and a supplemental inspection ('32-20-01 Nose Landing Gear Inspection') has been promulgated by the manufacturer to address the issue. In light of the history of related failures contained on the Australian record, the Australian Civil Aviation Safety Authority (CASA) is considering a review of their existing Airworthiness Bulletin, AWB 32-016 Cessna Single Engine Nose Landing Gear Forks, with respect to this issue.
Following recovery and preliminary examination of the GPS track data, it was evident that the most recent information stored on the device was recorded approximately twelve months prior to the accident. As such, the ATSB concluded that the unit had not been in use during or immediately prior to the accident flight, or the track recording functionality had been switched off.
Provision of information to the AIC:
The findings of the ATSB's examination of the nose landing gear and GPS examination were provided to the PNG-AIC on 7 January 2014, and the components were subsequently returned to the AIC investigator in-charge. The AIC is responsible for releasing a final investigation report into this occurrence.
- Contact details for Accident Investigation Commission (AIC) of Papua New Guinea
Released in accordance with section 25 of the Transport Safety Investigation Act 2003.