Incident Description
During an instructional flight, a landing was performed. During this landing, control of the aircraft was lost, and the aircraft subsequently collided with a snow bank. The impact was sufficiently forceful to shear off one of the main landing gear components. The other main landing gear collapsed, while the nose gear remained intact and did not collapse.
Pilot Report
The flight instructor (CFI) reported experiencing a severe shimmy in the aircraft. However, the instructor did not remember whether the shimmy began before or after the nosewheel touched down during the landing.
Mechanical Examination
An examination of the aircraft found no preexisting mechanical problem that could have contributed to the loss of control or the shimmy reported by the instructor.