Sequence of Events
During a simulated forced landing, the certified flight instructor (CFI) reduced engine power. The student pilot then established an approach to a road. As power was reapplied at the bottom of the approach, the engine accelerated to approximately 75% power before decelerating back to idle. Upon touchdown on the road, the left main wheel separated from the spring tube assembly. Subsequently, the nose gear failed due to overload, and the aircraft nosed over.
Damage
The left main wheel detached from its spring tube. The nose gear sustained an overload failure. The aircraft then nosed over as a result of the landing gear failures.
Investigation
Examination of the landing gear components revealed a fatigue fracture extending approximately 120 degrees around the circumference of the gear spring tube. The fracture was determined to have originated at the cross bolt hole.