ATA 27

Rear Horizontal Splice
We continue to get phone calls concerning the rear horizontal spar splice radial and axial play. Everybody wants to just jump in and replace the bushings and bearings. In fact, this is a major undertaking, requiring precise measurements and controls. Most, if not all, of these “excessive“ clearance problems can be brought under control by reading and applying Service Bulletin (SB) 1124-55-021 Paragraph E. sub. Paragraph 1.9 thru 1.12. It is a simple procedure that has excellent results. We have found that when the aircraft is re-assembled following splice replacement, the radial and axial measurements are already at or very near the limits called out in the Maintenance Manual, even with the splice having new bushings. It’s frustrating to the shop that after all that work, the tail is still “loose”. Using the above SB procedure will, in most cases, fix the problem. At the same time, take a look at the forward scissors, which have replaceable bushings. Keep them tight with shimming when needed.