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CORROSION OF THE ELEVATOR PUSHROD IN THE FIN

Several instances have been reported to GFA and Slingsby Aviation of corrosion in the lower end of the vertical elevator pushrod in the fin on T59 Kestrel sailplanes. This due to water entering through the witness hole for checking the engagement of the rod end thread. Access to the pushrod may be obtained by removing the tail wheel well. The pushrod should be inspected by removing the rod end (mark the rod end so that it can be reinstalled in the correct place), drilling a 3 mm hole in the bottom of the pushrod (see Figure 1) and shining a light through the hole and inspecting from the other end. If no corrosion is found a small amount of corrosion inhibiting paint should be poured into the pushrod an sloshed around to evenly coat the interior of the tube and the excess paint drained out. The hole drilled in the bottom of the tube must be left open as a drain hole. If significant corrosion is found then it must be repaired to an approved repair scheme. In most cases the repair schemes in AC 43.13-1a Acceptable Methods, Techniques and Practices will be used. Other repair schemes must be approved by the CTOA. After repair the interior of the tube must be painted and a drain hole installed as above. Slingsby Technical Instruction 106 refers.