# Textron Aviation Single Engine Mandatory Service Letter SEL-55-01: No revision named - Rights: © Textron Aviation Inc. Filed by the FAA in regulations.gov docket FAA-2020-0472; AD 2020-21-22 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Textron Aviation Single Engine Mandatory Service Letter SEL-55-01](https://openairdocs.org/service-documents/cessna/sel55-01.md) - Title as filed: Cessna SEL-55-01 - Pages: 9 - PDF: https://openairdocs.org/files/sha256/10/9f/109f898b550d81b0182ee334abf1544aaefe690d53f4d20ac8b08ca98ebd7d64 - Page: https://openairdocs.org/service-documents/cessna/sel55-01/file/109f898b550d ## Text This text is OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 (OCR) Single Reechcraft Hawker Engine SERVICE LETTER TEXTION AVIATION MANDATORY SEL-55-01 TITLE STABILIZERS - TAILCONE AND HORIZONTAL STABILIZER INSPECTION EFFECTIVITY This service document applies to all models and serial numbers listed that have more than 3000 total hours or 10 years in service. MODEL SERIAL NUMBERS 180 604, 614, 30000 thru 32639 180A 32662 thru 32999, 50001 thru 50355 180B 50356 thru 50661 180C 624, 50662 thru 50911 180D 18050912 thru 18051063 180E 18051064 thru 18051183 180F 18051184 thru 18051312 180G 18051313 thru 18051445 180H 645, 18051446 thru 18051875, 18051879 thru 18052284 180J 18052285 thru 18052489, 18052491 thru 18052770 180K 18052490, 18052771 thru 18053203 182 613, 33000 thru 33842 182A 33843 thru 34753, 34755 thru 34999, 51001 thru 51556 182B 34754, 51557 thru 51622, 51624 thru 52358 182C 631, 52359 thru 53007 182D 51623, 18253008 thru 18253598 185 632, 185-0001 thru 185-0237 185A 185-0238 thru 185-0512 185B 185-0513 thru 185-0653 185C 185-0654 thru 185-0776 185D 185-0777 thru 185-0967 A 185E 185-0968 thru 18502090 A185F 652, 18502091 thru 18502301, 18502311 thru 18504448 SEL-55-01 December 7, 2017 Page 1 of 9 Textron Aviation Customer Service, P.O. Box 7706, Wichita, KS 67277, U.S.A. 1-316-517-5800 This document accordance win expor admis said regulatos. Diversion con Thary to Us. tay a profited. CON SEe Uniled States COPYRIGHT © 2017 ### Page 2 (OCR) Single Beechcraft Hawker. Engine SERVICE LETTER Cessna TEXTRON AVIATION MANDATORY SEL-55-01 REASON Reports have been received of cracks in the tailcone reinforcement angle, stabilizer hinge bracket and stabilizer. Noncompliance with this service letter may allow crack(s) to go undetected. Undetected cracks may cause structural failure of the horizontal stabilizer and could result in the loss of control in flight. DESCRIPTION This service document provides instructions to inspect the tailcone and horizontal stabilizer. COMPLIANCE MANDATORY. This service document must be accomplished at the next 100-hour or 12-month (annual-type) inspection, whichever occurs later. NOTE: After the initial inspection, this service letter inspection must be completed every 500 hours or 5 years, whichever occurs first. A service document published by Textron Aviation may be recorded as completed in an aircraft log only when the following requirements are satisfied: 1) The mechanic must complete all of the instructions in the service document, including the intent therein. 2) The mechanic must correctly use and install all applicable parts supplied with the service document kit. Only with written authorization from Textron Aviation can substitute parts or rebuilt parts be used to replace new parts. 3) The mechanic or airplane owner must use the technical data in the service document only as approved and published. 4) The mechanic or airplane owner must apply the information in the service document only to aircraft serial numbers identified in the Effectivity section of the document. 5) The mechanic or airplane owner must use maintenance practices that are identified as acceptable standard practices in the aviation industry and governmental regulations. No individual or corporate organization other than Textron Aviation is authorized to make or apply any changes to a Textron Aviation-issued service document or flight manual supplement without prior written consent from Textron Aviation. Textron Aviation is not responsible for the quality of maintenance performed to comply with this document, unless the maintenance is accomplished at a Textron Aviation-owned Service Center. CONSUMABLE MATERIAL No specialized consumable materials are required to complete this service document. TOOLING NAME NUMBER MANUFACTURER USE 10X Magnifying Commercially Available To perform visual inspection. Glass Boroscope Commercially Available To perform visual inspection. REFERENCES Model 100 Series (1953-1962) Maintenance Manual Model 100 Series (1963-1968) Maintenance Manual Model 180/185 Series (1969-1980) Service Manual Model 180/185 Series (1981-1985) Service Manual NOTE: To make sure all publications used are complete and current. Refer to www.txtavsupport.com. SEL-55-01 Page 2 December 7, 2017 ### Page 3 (OCR) Single Beechcraft Hawker Engine SERVICE LETTER Cessna TEXTRON AVIATION MANDATORY SEL-55-01 PUBLICATIONS AFFECTED None ACCOMPLISHMENT INSTRUCTIONS 1. Prepare the airplane for maintenance. A. Make sure that the airplane is electrically grounded. B. Make sure that all switches are in the OFF/NORM position. C. Disconnect electrical power from the airplane. (1) Disconnect the airplane battery. (2) Disconnect external electrical power. D. Attach maintenance warning tags to the battery and external power receptacle that have "DO NOT CONNECT ELECTRICAL POWER - MAINTENANCE IN PROGRESS" written on them. 2. Remove all fin and horizontal stabilizer tail fairings as needed. 3. (Airplanes with tailwheel steering.) Disconnect the tailwheel steering cables from the tailwheel bellcrank. For Models 180 and 185(1953-1968) refer to Section 5, Landing Gear - Tail Gear. For Models 180 and 185(1969-1985) refer to Section 9, Rudder and Rudder Trim Control Systems - Cables and Pulleys - Removal and Installation - Tailwheel Steering Cables. 4. Remove the stinger from the tail section. 5. Disconnect the rudder control cables at the rudder bellcrank. For Model 180, 182 and 185(1953-1962) refer to Section 10, Rudder Control System - Removal of Rudder Cables. For Models 180 and 185(1963-1968) refer to Section 10, Rudder and Rudder Trim Control Systems - Removal and Installation of Rudder Cables. For Models 180/185 (1969-1985) refer to Section 9, Rudder and Rudder Trim Control Systems - Cables and Pulleys - Removal and Installation - Aft Cables. 6. Disconnect the bellcrank tube from the elevator pylon. For Model 180, 182 and 185(1953-1962) refer to Section 8, Elevator Control System - Aft Bellcrank. For Models 180 and 185(1963-1968) refer to Section 8, Elevator Control System - Rear Bellcrank. For Models 180/185 (1969-1985) refer to Section 8, Elevator Control System - Bellcranks. 7. (Refer to Figure 1 Detail A and Figure 2 Detail B.) Remove attaching hardware at the stabilizer hinge assemblies and stabilizer hinge brackets For Models 180, 182 and 185(1953-1968) refer to Section 4, Airframe - Horizontal Stabilizer. For Models 180/185 (1969-1985) refer to Section 10, Stabilizer Trim Control System - Stabilizer. 8. Lift the horizontal stabilizer from the empennage and place a wooden or padded support between the two pieces. 9. (Refer to Figures 1 and 2.) Clean the following areas to be inspected (Refer to Section 2, Ground Handling, Sevicing, Cleaning, Lubrication and Inspection - Cleaning in the applicable model maintenance manual.): Stabilizer hinge brackets Tailcone reinforcement angles Corner reinforcements Stabilizer hinge reinforcement channel Stabilizer hinge assemblies Stabilizer aft spar reinforcement SEL-55-01 December 7, 2017 Page 3 ### Page 4 (OCR) Single Beechcraft Hawker Engine SERVICE LETTER TEXTION AVIATION MANDATORY SEL-55-01 • Lower half of the stabilizer aft spar from STA 16 on the left side of the stabilizer aft spar to STA 16 on the right side NOTE: If the inspection area cannot be cleaned adequately, removal of the horizontal stabilizer and the fin may be necessary. For Models 180, 182 and 185(1953-1968) refer to Section 4, Airframe - Horizontal Stabilizer and Section 4, Airframe - Fin. For Models 180/185 (1969-1985) refer to Section 10, Stabilizer Trim Control System - Stabilizer and Section 4, Wings and Empennage - Fin. 10. If any corrosion is found, it must be removed before refinishing. (Refer to Section 2A, Supplemental Inspection Documents - Corrosion (for corrosion removal) and Section 2A, Supplemental Inspection Documents - Nondestructive Inspection Methods and Requirements (for measurement of part thickness) in the applicable model maintenance manual.) 11. (Refer to Figures 1 and 2.) Do a detailed inspection of the following areas (Refer to Section 2A, Supplemental Inspection Documents - Nondestructive Inspection Methods and Requirements - Visual Inspections in the applicable model maintenance manual.): Stabilizer hinge brackets Tailcone reinforcement angles Corner reinforcements Stabilizer hinge reinforcement channel Stabilizer hinge assemblies Stabilizer aft spar reinforcement Lower half of the stabilizer aft spar from STA 16 on the left side of the stabilizer aft spar to STA 16 on the right side WARNING: If any cracks are found, no further flight is permitted. The part must be replaced before further flight. NOTE: If the inspection area cannot be viewed adequately, removal of the horizontal stabilizer and the fin may be necessary. For Models 180, 182 and 185(1953-1968) refer to Section 4, Airframe - Horizontal Stabilizer and Section 4, Airframe - Fin. For Models 180/185 (1969-1985) refer to Section 10, Stabilizer Trim Control System - Stabilizer and Section 4, Wings and Empennage - Fin. 12. Record the inspection findings on the attached Visual Inspection Results Form. 13. If any cracks are found during the inspection, the part must be replaced before further flight. 14. Remove the wooden support between the horizontal stabilizer and the empennage. 15. (Refer to Figure 1 Detail A and Figure 2 Detail B.) Install attaching hardware at the stabilizer hinge assemblies and stabilizer hinge brackets For Models 180, 182 and 185(1953-1968) refer to Section 4, Airframe - Horizontal Stabilizer. For Models 180/185 (1969-1985) refer to Section 10, Stabilizer Trim Control System - Stabilizer. 16. Connect the bellcrank tube to the elevator pylon. For Models 180, 182 and 185(1953-1962) refer to Section Section Elevator Control System - Aft Bellcrank. For Models 180 and 185(1963-1968) refer to Section 8, Elevator Control System - Rear Bellcrank. For Models 180/185 (1969-1985) refer to Section 8, Elevator Control System - Bellcranks. 17. Connect the rudder control cables at the rudder bellcrank. For Model 180, 182 and 185(1953-1962) refer to Section 10, Rudder Control System - Installation of Rudder Cables For Models 180 and 185(1963-1968) refer to Section 10, Rudder and Rudder Trim Control Systems - Removal and Installation of Rudder Cables. For Models 180/185 (1969-1985) refer to Section 9, Rudder and Rudder Trim Control Systems - Cables and Pulleys - Removal and Installation - Aft Cables. 18. (Airplanes with tailwheel steering.) Connect the tailwheel steering cables to the tailwheel bellcrank. For Models 180 and 185(1953-1968) refer to Section 5, Landing Gear - Tail Gear. SEL-55-01 Page 4 December 7, 2017 ### Page 5 (OCR) Single Reechcraft Hawker Engine SERVICE LETTER Cessna TEXTRON AVIATION MANDATORY SEL-55-01 For Models 180 and 185(1969-1985) refer to Section 9, Rudder and Rudder Trim Control Systems - Cables and Pulleys - Removal and Installation - Tailwheel Steering Cables. 19. Install the stinger onto the tail section. 20. Install all fin and horizontal stabilizer tail fairings. 21. Remove the maintenance warning tags and connect the airplane battery. 22. Send completed form/attachments to Cessna Structures at csstructures@txtav.com 23. Make an entry in the airplane logbook that states compliance and method of compliance with this service document. SEL-55-01 December 7, 2017 Page 5 ### Page 6 (OCR) Single Beechcraft Hawker Engine SERVICE LETTER Ces TEXTRON AVIATION MANDATORY SEL-55-01 B21657 C B. A DETAIL A D_ Stabilizer Hinge Bracket Tailcone Reinforcement Angle Stabilizer Hinge Bracket Tailcone Reinforcement Angle DETAIL B Looking Down, Inboard Right Side Shown, Left Side Opposite DETAIL C Looking Down, Outboard Right Side Shown, Left Side Opposite Figure 1. Tailcone Inspection (Sheet 1) SEL-55-01 Page 6 December 7, 2017 ### Page 7 (OCR) Engine Single SERVICE LETTER Beechcraft Cessna Hawker TEXTRON AVIATION MANDATORY SEL-55-01 B21660 E Tailcone Reinforcement Angles DETAIL D Parts Shown Removed From Tailcone Inboard surface 8 Identified Crack Upper edge of stringer DETAIL E Figure 1. Tailcone Inspection (Sheet 2) SEL-55-01 December 7, 2017 Page 7 ### Page 8 (OCR) Single Reechcraft Hawker Engine SERVICE LETTER Cessna TEXTRON AVIATION MANDATORY SEL-55-01 B21658 B,C 0000 000 000 00 Corner Reinforcement (Right Side Shown, Stabilizer Hinge Left Side Opposite) DETAIL A Reinforcement Looking Aft Skin Has Been Channel Removed For Clarity DETAIL C Looking Forward Right Side Shown, Stabilizer Hinge Assembly Left Side Opposite DETAIL B Looking Up and Forward Left Side Shown, Right Side Opposite Figure 2. Horizontal Stabilizer Inspection (Sheet 1) SEL-55-01 Page 8 December 7, 2017 ### Page 9 (OCR) Single Beechcraft | Cossna Hawker Engine SERVICE LETTER TECTION AVIATION MANDATORY SEL-55-01 B21659 191 VIEW A-A Horizontal Stabilizer Looking down Stabilizer Hinge Reinforcement Channel Stabilizer Aft Spar Reinforcement Stabilizer Aft Spar VIEW B-B (Reference) Centerline Right Side Shown, Left Side Opposite Looking Forward STA 16.00 (Right) (Reference) Figure 2. Horizontal Stabilizer Inspection (Sheet 2) SEL-55-01 December 7, 2017 Page 9 --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.