On Thursday 15 June 2000 at around 1400, ZK-RCA, a Metro III, landed on runway 14 at Gisborne Aerodrome at which time its left undercarriage drag braces both failed, causing the left undercarriage to collapse aft. A go-around was carried out and the aircraft flown to Hamilton Aerodrome for a wheels-up landing. The 2 pilots on board the aircraft were not injured.
The undercarriage failure resulted from a fatigue crack that had developed and grown to a critical length in the left undercarriage outboard lower drag brace. The fatigue crack started in a recess machined to accommodate a grease fitting, near the attachment point to the undercarriage leg. The crack was not detectable during normal maintenance procedures. The inboard drag brace failed in overload when the outboard drag brace failed.
Safety issues identified included the need for improved design and inspection requirements for Metro aircraft undercarriage drag braces. The manufacturer and the United States and New Zealand safety authorities addressed the safety issues. No safety recommendations were required.
