To:747FOCAL
Here is what I heard that happened: Under normal conditions when an engine is removed an/or installed on the wing the engine is mounted on an installation / removal dolly. The dolly has various mechanical controls that allow precision positioning of the engine in relation to the pylon.
In order to expedite the installation the mechanics raised the engine into position using a forklift.
Since the forklift lacked precision positioning capabilities the engine struck a diaphragm on the pylon causing it to crack. This element although fragile by itself it provides a great deal of structural integrity to the pylon assembly. With the damaged diaphragm the pylons structural integrity was severely compromised leading to its’ failure under high thrust levels.
