19970626020049A

(.4)The pilot in command reported that after an hour long local flight he was returning to make a full stop landing on runway 30. The pilot reported that the touchdown was, 'very smooth and normal, with the power at idle.' The pilot stated that during the landing rollout, 'the aircraft pitched forward and then rotated violently to the left.' The pilot reported that during the left rotation, 'the airplane rolled up onto both right wingtips, and then fell vertically onto its nose.' The airplane came to rest in a nose down attitude, supported by the left wing and right main gear. The left main landing gear axle and support tube were sent to the national transportation safety board materials laboratory division for inspection. The lab report states there was evidence 'indicative of a preexisting brittle fracture area such as fatigue cracking.' The inspection also revealed thinned areas of the tube. (-23) during landing roll-out, left main gear axle severed and separated from the aircraft. Left main strut dug into the turf (runway 03) and the aircraft spun around (groundloop) causing substantial damage to the wings. CA rburetor box was torn off. The wooden propeller was shattered to splinters and the aircraft came to rest standing on its nose.