Hanger bracket failure:
Read an article (courtesy of LAA) about a Hanger bracket failure where the triangular plate (F153 at front end of boom tube) failed. PDF (500kB)
Worn wing attachments:
In February 2012, I was asked to do urgent repairs to a 1986 Shadow C-D. It had been grounded because of excessive movement in the wing-to-fuselage attachments. The tail end of the boom could be moved up and down about 45mm without affecting the fuselage. The boom tube was resting on the alloy gusset that ties the two rear hanger tubes together.
The following PDF shows the wear that was found inside.
Worn wing attachments (1986 kitset Shadow C-D).
You can see what is possible on older Shadows, especially those built from kitsets. It would be worth checking your Shadow for any up/down movement of the boom (relative to the hanger tubes).
The actual repairs were very quick, with most of the labour absorbed in dismantling the wing’s centre section from the fuselage and removing the boom, followed later by re-assembly, covering and painting.