scope:

Description of Driving Event:

When a test fixture was commanded to rotate, the rotation machinery was actuated but the fixture failed to rotate. Visual inspection of the fixture revealed deformation and damage of several fixture components. The drive system had a mechanical stop in place to prevent over-rotation of the fixture cradle. Subsequent analysis indicated that the drive system had sufficient torque capability to overload the drive train should the drive train operate after the mechanical stop was engaged. Damage to the test fixture was estimated at $20K.

Lesson Submitted from the Boeing International Space Station (ISS) Lessons Learned Database:

From Boeing ISS dated 8/96, was entitled "Rotating/Moving Equipment Mechanical Stops"