Re: Fin Rib Kits
Jim,
Could you expand on the differences between the SB114-12B kit and the variant used on the 114B/TC? For those of us that do have the -12B (or corresponding SB112-56B on the 112s) kit installed, what improvement(s) does the 114B/TC rib bring to the table? Have you come across any airplanes with the -12B or -56B kit installed that redeveloped cracks?
Also -- for those that aren't aware -- the SB114-12B and SB112-56B kits introduced the "double rivet line" to the area just below the horizontal stabilizer. There were two earlier SB's released to try and fix the problem with cracking in that rib, neither of which quite did the trick.
Another side comment: When I bought my 114, the owners had the SB114-12B kit sitting in the hangar. The invoice showed it was free of charge from Commander (early '90s), but they never bothered to have their A&P install the kit. Even though the earlier SB had been completed and didn't show any signs of cracking, one of my first major maintenance events included having the -12B modification installed. Just for peace of mind.