After an investigation, the National Transportation Safety Board reported probable cause of the crash was " corrosion " and a " fatigue fracture " involving the left wing of the 67-year-old float-equipped Taylorcraft BF12 owned by Wiley.
12.
Two months later, according to the safety board, a fatigue fracture " undetected or improperly repaired " at a repair station caused a propeller to rip off a Southeast Airlines plane cruising 18, 000 feet above western Georgia.
13.
The greater stiffness of flat-bottom was an advantage, but it tended to straighten out between the joints on curves; and flat bottom s rigidity led to high vertical impact forces at badly maintained joints and this resulted in high volumes of fatigue fractures at the joints.
14.
There are also many material issues : a harder material may be more durable against abrasion but more likely to suffer fatigue fracture, so the material varies with the application, and while steel is most common for rolling-element bearings, plastics, glass, and ceramics are all in common use.
15.
Scott and his party work out that " the bear " could refer to a lake, Dancing Bear Water, 30 or 40 miles back along the flight path of the lost aircraft and there, in due course, they find the tailplane and its front spar root, reveals a classic fatigue fracture.
