Instructions for Continued Airworthiness

Note: Some of the Cessna 150 models utilized smaller diameter hardware and incorporated screws instead of bolts along the leg of the vertical fin fitting. In these instances, the vertical stabilizer holes would also need to be enlarged. Aircraft that were produced with the enlarged holes should either require light reaming or no hole enlargement for installation. Figure 4: Example of alignment bushings in vertical stabilizer (Step 8). Figure 5: Example of using screws to clamp the part to the vertical stabilizer for drilling out procedure (Step 8). Alignment bushings inserted in vertical stabilizer visible. Instructions for Continued Airworthiness McFarlane Aviation, LLC. FAA-PMA Part Number MC0431148-1 Vertical Fin Fitting. FAA PMA Number: PQ3732CE Page 5 of 7 McFarlane Drawing: 7927 9. The pilot holes along the legs of the vertical fin fitting need to be back drilled and reamed to 0.191 inches per AC 43.13. This drilling procedure allows installers to achieve the best fit of the vertical fin fitting on their aircraft. It is recommended that each hole initially be enlarged with a #13 drill bit, followed by a reamer to achieve the necessary hole size. Ensure that the vertical stabilizer is perpendicular to the horizontal stabilizer prior to enlarging the holes of the vertical fin fitting. Use diagonal measurements or angle measuring equipment. Note: It is recommended that the old hardware be utilized for temporarily holding the fitting in position while enlarging the fitting holes. Note: The recommended procedure using the Alignment Bushings is shown in Figure 6 through Figure 9. When enlarging the vertical fin fitting holes, the Alignment Bushings aid in keeping the holes aligned by guiding the cutting tool. a. Start by drilling out the middle hole on the leg. Once this hole has been drilled, use the bolt and nut (part numbers NAS464P3A7 and MS21043-3) to lightly fasten the leg of the vertical fin fitting to the vertical stabilizer. This increases stability and holds the part in position as you continue to drill and ream, while allowing for some movement if necessary to achieve the best fit. b. Repeat this drilling and reaming process for all holes on the leg, moving progressively outward from the middle hole position and alternating between holes located above and below the middle hole. Figure 6: Alignment Bushing and Solid Pilot Counterbore used to enlarge hole to a #13 drill size Figure 7: Alignment Bushing used to guide the Pilot of the Counterbore Figure 8: As the hole is enlarged in the vertical fin fitting, the Pilot continues to travel through the Alignment Bushing Figure 9: Remove the bushing and drill through the other leg of the vertical fin fitting Vertical Fin Fitting Alignment bushing in vertical stabilizer Instructions for Continued Airworthiness McFarlane Aviation, LLC. FAA-PMA Part Number MC0431148-1 Vertical Fin Fitting. FAA PMA Number: PQ3732CE Page 6 of 7 McFarlane Drawing: 7927 10. After holes have been drilled, remove the fasteners from along the leg of the vertical fin fitting (part numbers NAS464P3A7 and MS21043-3). 11. Remove the fasteners from the base of the vertical fin fitting (part numbers AN4-6A, AN960-416L, and MS21042L4). 12. Remove the vertical fin fitting from the aircraft. 13. Debur the holes along the legs of the vertical fin fitting and stabilizer. Note: The McFarlane vertical fin fitting has a different profile than the OEM part, which may result in exposed unpainted metal on the vertical and horizontal stabilizer (example shown in Figure 10). It is recommended that this metal be painted per the applicable Cessna Service Manual. 14. Apply corrosion-resistant primer to the holes along the legs of the vertical fin fitting. 15. Remove any debris/swarf that resulted from the machining process in Step 9 from the aircraft. 16. Place the vertical fin fitting back into position on the aircraft. Note: It is recommended that the vertical stabilizer skin be minimally trimmed if it is contacting the inner radius of the slot of the vertical fin fitting. 17. Use part numbers AN4-6A, AN960-416L, and MS21042L4 to fasten the base of the vertical fin fitting to the horizontal stabilizer. Torque bolts AN4-6A to 70-100 lb. inches per Cessna Service Letter SE79-49 Revision #1 and Model 152 Series 1978 Thru 1985 Service Manual. 18. Use part numbers NAS464P3A7, AN960-10, and MS21043-3 to fasten the legs of the vertical fin fitting to the vertical stabilizer. Torque nuts MS21043-3 to 46 lb. inches. 19. Repeat Steps 4-18 for the other vertical fin fitting, if applicable. Figure 10: Example of unpainted metal in front of the base of the fitting on the horizontal stabilizer, and near the bottom edge of the vertical stabilizer TROUBLESHOOTING Refer to the applicable Cessna Model Service Manuals (see Data Section below for listings) and AC 43.13 for troubleshooting instructions. PLACARDS None applicable. FWD Instructions for Continued Airworthiness McFarlane Aviation, LLC. FAA-PMA Part Number MC0431148-1 Vertical Fin Fitting. FAA PMA Number: PQ3732CE Page 7 of 7 McFarlane Drawing: 7927 DATA All information to support the continued airworthiness of this replacement part is as defined herein and contained in: • Relevant Cessna Model Service Manuals. o Service Letter, SE78-62 o Service Letter, SE79-49 Revision #1 o MODEL 100 SERIES SERVICE MANUAL (1963 Thru 1968), D637-1-13 o MODEL 150 SERIES 1969 THRU 1976 SERVICE MANUAL, D971-3-13 o MODEL 150 SERIES 1977 SERVICE MANUAL, D2011-1-13 o MODEL 152 SERIES 1978 THRU 1985 SERVICE MANUAL, D2064-1-13 • Relevant Cessna Model Illustrated Parts Catalog. o MODEL 150 PARTS CATALOG (1959 THRU 1969), P438-12 o MODEL 150 PARTS CATALOG (1970 THRU 1977), P691-12 o MODEL 152 PARTS CATALOG (1978 THRU 1985), P692-13 INSPECTION The Cessna Service Manuals require frequent inspection of the vertical fin fittings. All inspections should continue to be performed as instructed in the Cessna Service Manuals. This includes but is not limited to: • Supplemental Inspection Number: 55-11-03 Vertical Stabilizer Attach Bracket and Horizontal Stabilizer Rear Spar Attachment Inspection – Model 150 • Supplemental Inspection Number: 55-11-03 Vertical Fin Attach Bracket Inspection • Supplemental Inspection Number: 55-10-01 Horizontal Stabilizer, Elevators and Attachments Inspection • Supplemental Inspection Number: 55-30-01 Vertical Stabilizer, Rudder and Attachments Inspection • Supplemental Inspection Number: 55-11-02 Vertical Stabilizer Attach Bracket and Horizontal Stabilizer Rear Spar Attachment Inspection RECOMMENDED OVERHAUL PERIODS No additional overhaul time limitations exist with the use of these parts. AIRWORTHINESS LIMITATIONS The Airworthiness Limitations section is FAA approved and specifies maintenance required under Sec. 43.16 and 91.403 of the Federal Aviation Regulations unless an alternative program has been FAA approved. No additional airworthiness limitations exist. ASSISTANCE & REVISIONS ICA revisions shall be made available on the McFarlane website, www.mcfarlaneaviation.com/ICA. For questions or assistance regarding these Instructions for Continued Airworthiness (ICA), contact McFarlane Aviation, Inc via email or phone. Email: engineering@mcfarlaneaviation.com Phone: 1-800-544-8594 (within the US) or 1-785-594-2741.