After a smooth touchdown and a landing roll of about 150 metres, the right undercarriage leg collapsed. The aircraft veered right about 25 metres off the runway and came to rest in soggy ground. Prior to touchdown the landing gear had been confirmed down by the pilot and had been seen down by ground witnesses. An engineering inspection discovered that an end fitting on the link assembly side bracing lock had partially seized. This had prevented the right undercarriage leg from locking down. The last 100 hourly periodic inspection had been carried out eleven months prior to the accident. Since then the aircraft had flown only 60 hours. The end fitting lacked lubrication and is not equipped with a grease nipple. This accident was not the subject of an on-scene investigation.