A fracture failure of the lower end of the spring steel landing gear strut. Factors contributing to the accident were the manufacturer's and the FAA's insufficient standards/requirements for inspection procedures.

The pilot's failure to maintain directional control resulting in a inadvertent ground loop. A contributing factor was the induced pressure on the pilot by a sick passenger.

THE PILOT-IN-COMMAND NOT MAINTAINING DIRECTIONAL CONTROL. A FACTOR IS THE ROUGH CONDITION OF THE GLACIER AIRSTRIP.