Glasair Aviation published a service bulletin to address crushed or delaminated portions of the tail cone near the aft tailwheel bracket. The SB is applicable to all Sportsman aircraft serial numbers 7000-7450.
For more about this bulletin, refer to this topic in the GAOA forum.
From the Service Bulletin:
It has come to our attention that a number of Sportsman tailwheel installations have resulted in crushed and/or delaminated fuselage laminates near the aft tailwheel bracket. This is due to occasional shock loads transmitted through the small wedge shaped aluminum block above the tailwheel leaf springs. In several extreme cases, partial dis-bonding of the aft most fuselage bulkhead flange (Bulkhead “E”) to the fuselage may have occurred.
Some of the dis-bonds are easily visible, while others may appear to be superficial. In most cases, sanding off the interior fuselage laminates on the lower third of the flanges of bulkhead “E” and along the fuselage seam above the tailwheel leaf spring assembly exposes deeper cracks, voids, and delamination.
This service bulletin covers the removal of the tailwheel assembly, inspection of the aft fuselage between bulkheads “D” and “E,” reinforcement of this area, and the optional, but recommended replacement of the aft tailwheel attachment.
Through the investigation of this problem we became aware of a small likelihood of occurrence of failed laminates attaching bulkhead “E” to the fuselage shell. Out of an abundance of caution we request that all fuselages Serial No: 7300 – 7450 perform the bulkhead flange inspection.