Tail Rotor Driveshaft Hanger

BHT-212-CR&065-17. Repaircoo...La=`goo'-o3EECADE-0MATERIALS REQUIREDRefer to BHT-ALL-SPM for specification andsource.NUMBERC-100C-105C-108C-112C-116C-204C-308C-423C-432C-494CJ)cc-0U)ENOMENCLATUREChemical Film MaterialCorrosion PreventiveBrush CadmiumPlating SolutionCadmium ChromateConversion Coating00Chromic AcidPrimerAdhesiveAbrasive cloth orPaperNitric AcidInkNOTEReplace case if structural damage tostud threads or mounting bolt holesare elongated so repair limits areexceeded.1. Replace parts which exceed allowablewear limits.2. Repair corrosion damage on the case asfollows (figure 65-7):a. Flange repair: Machine off upper faceto a minimum flange thickness of 0.40 inch(10.16 mm) (dimension B, figure 65-7)provided this leaves no pits in excess of0.010 inch (0.254 mm) deep and affectedarea does not exceed inspection limits.Rework case using a 0.875 inch (22.225 mm)...momfro3.213.00diameter spotface with 0.062 inch (1.5748mm) corner radius. Machined surface finishshall be 63 RMS or better.65-00-00Page 20Rev.4b. Stud hole damage: Remove damagedor loose studs. Use suitable tool to grip studand turn out slowly and evenly to avoidseizure and breakage. If stud hole threads aredamaged, repair or replace case as required.a0-5 -"`con'-"cc.,-«4+,aS11C70If corrosion or other damage has notpenetrated past first thread,follows (BHT-ALL-SPM):D.c((DD33.rework case as(1) Machine or drill out damagedthread. Do not exceed depth of one thread.2.3Clean out diameter shall equal major threaddiameter.(2) Break all sharp edges, except inarea of threads. Clean out small vent hole inbottom of threaded hole. Treat bare surfaceswith chemical film material (C-100).(3) Replace stud (BHT-ALL-SPM).(4). Fill all counterdrilled holes withadhesive (C-308) flush with top of case.c. Repair minor scratches, nicks, and pitson noncritical surfaces with abrasive cloth orpaper (C-423).d. Cases with corrosion damage withinacceptable limits must be treated byimmersion in a hot chromic acid bathconsisting of 20 to 24 ounces (591.4 to709.68 ml) of chromic acid (C-116) per gallon(/j3-t3-firc>,=r,