TITLE NACELLES/PYLONS - NACELLE FITTING INSPECTION EFFECTIVITY REASON MODEL 402C 414A SERIAL NUMBERS 402C0001 thru 402C1020 that have SK402-47 - Lower Front Wing Spar Cap Inspection/Modification (Original issue, Revision A or B) installed. 414A0001 thru 414A1212 that have SK402-47 - Lower Front Wing Spar Cap Inspection/Modification (Original issue, Revision A or B) installed. Cracks have been discovered on some 5292029 Nacelle Fittings. An undetected crack can cause the nacelle fitting to break which could result in flight instability. DESCRIPTION This service letter provides instructions to complete a borescope visual inspection of the four 5292029 Nacelle Fittings for cracks. COMPLIANCE. This service letter must be accomplished on each nacelle fitting as listed in the table that follows. The time for this document starts on the date of receipt. NOTE: To find the 5292029 Nacelle Fitting Hours, in the airplane logbook, find the airplane flight hours when compliance with Airworthiness Directive (AD) 2005-12-13 by installation of SK402-47 - Lower Front Wing Spar Cap Inspection/Modification. Take the current airplane flight hours and subtract the flight hours when SK402-47 was installed; this is the current hours for the nacelle fittings. NOTE: The 5292029 Nacelle Fittings with less than 7,500 flight hours are not subject to this inspection until that nacelle fitting reaches 7,500 flight hours. 5292029 Nacelle Fitting Hours Flight Hours To Comply With Initial Inspection Flight Hours for Recurring Inspection 13,400 and above before further flight every 25 flight hours 12,400-13,399 in the next 25 flight hours every 25 flight hours 11,400-12,399 in the next 50 flight hours every 50 flight hours 10,400-11,399 in the next 100 flight hours every 100 flight hours 7,500-10,399 in the next 200 flight hours every 200 flight hours NOTE: The recurring inspection applies to all nacelle fittings with more than 7,500 flight hours. Once a nacelle fitting is replaced, that nacelle fitting no longer has a requirement for the recurring inspection until it has reached 7,500 flight hours. December 23, 2016 Page 1 of 15 Textron Aviation Customer Service, P.O. Box 7706, Wichita, KS 67277, U.S.A. 1-316-517-5800 This document contains technical data and is subject to U.S. export regulations. This information has been exported from the United States in accordance with export administration regulations. Diversion contrary to U.S. law is prohibited. ECCN: 9E991 COPYRIGHT 2016
TOOLING NAME NUMBER MANUFACTURER USE Flexible Borescope Commercially Available Do the visual examination. REFERENCES Cessna Model 402C Maintenance Manual Cessna Model 414 Maintenance Manual Attached Reference Images 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. (Refer to Figure 1, Sheets 1 thru 12 for reference images.) Use a borescope to do a visual inspection of the 5292029 Nacelle Fittings for cracks. NOTE: There are two methods to inspect the outboard and inboard nacelle fittings and a third alternate method to inspect the inboard only fittings. Method one is to insert the borescope through a lightening hole at the forward end of each engine beam. Work the borescope aft to inspect the nacelle fittings. Method two is to remove the rectangular and fuel filter access panels from the lower nacelle and then insert the borescope through the access panels. Work the borescope forward to inspect the nacelle fittings. Method three is an alternate method for the inboard nacelle fitting only. Remove the sealant aft and outboard of the nacelle fitting and then insert the borescope through the gap between the lower panel and the nacelle fitting. Work the borescope forward to inspect the nacelle fittings. NOTE: If the nacelle fitting is dirty, it may be necessary to remove the lower aft nacelle skin panels to clean the nacelle fitting sufficiently for inspection. A. (If using method 1.) Remove the cowling as necessary to access the forward lightening hole in the engine beams. (Refer to the appropriate model maintenance manual.) B. (If using method 2.) Remove the rectangular and fuel filter access panels from the lower nacelles. (Refer to the appropriate model maintenance manual.) C. (If using method 3 for the inboard nacelle fitting.) Remove the sealant from the aft and outboard edge of the inboard nacelle fittings. (Refer to the appropriate model maintenance manual.) D. Complete the attached VISUAL INSPECTION RESULTS FORM while inspecting each nacelle fitting. Page 2 December 23, 2016
WARNING: FURTHER FLIGHT WITH A CRACKED NACELLE FITTING IS PROHIBITED. THE NACELLE FITTING MUST BE REPLACED BEFORE FURTHER FLIGHT. E. If a crack is found, make a logbook entry for that nacelle fitting. The nacelle fitting must be replaced before the next flight. F. If no cracks are found, make a logbook entry that states the recurring inspection is due at the specified flight hour interval as listed in the COMPLIANCE section of this service letter. NOTE: An example of a log book entry on an airplane that currently has 28,500 airplane flight hours and 13,500 flight hours on the nacelle fitting, the next inspection is due at 28,525 airplane flight hours. Nacelle Fitting Inspection must be accomplished on or before 28,525 airplane flight hours for the left outboard, left inboard, right inboard, and right outboard positions. NOTE: An example of a log book entry on an airplane that currently has 23,500 airplane flight hours and 8,500 flight hours on the nacelle fitting and the left outboard and left inboard nacelle fittings were replaced during the initial inspection, two log book entries could read as follows: Nacelle Fitting Inspection must be accomplished on or before 23,700 airplane flight hours for the right inboard, right outboard positions. Nacelle Fitting Inspection must be accomplished on or before 31,500 airplane flight hours for the left inboard and left outboard positions. 3. Install removed access panels and cowling that were removed to complete the inspection. (Refer to the appropriate model maintenance manual.) 4. (If inspection method 3 was used for the inboard nacelle fittings.) Seal the gap at the aft and outboard edge of the nacelle fitting. (Refer to the appropriate model maintenance manual.) 5. Remove the maintenance warning tags and connect the airplane battery. 6. Make sure the VISUAL INSPECTION RESULTS FORM is submitted to Cessna Structures at csstructures@txtav.com. 7. Make an entry in the airplane logbook as follows: that states compliance and method of compliance with this service document the airplane flight hours at the time of inspection the nacelle fittings that were inspected, the flight hours for each nacelle fitting and result of the inspection. December 23, 2016 Page 3
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 1) Page 4 December 23, 2016
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 2) December 23, 2016 Page 5
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 3) Page 6 December 23, 2016
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 4) December 23, 2016 Page 7
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 5) Page 8 December 23, 2016
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 6) December 23, 2016 Page 9
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 7) Page 10 December 23, 2016
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 8) December 23, 2016 Page 11
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 9) Page 12 December 23, 2016
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 10) December 23, 2016 Page 13
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 11) Page 14 December 23, 2016
Figure 1. NACELLE FITTING INSPECTION REFERENCE IMAGES (Sheet 12) December 23, 2016 Page 15
ATTACHMENT VISUAL INSPECTION RESULTS FORM Airplane Serial Number Total Airframe Hours Owner's Name Owner's address Left Engine Hours Right Engine Hours Inspection Facility Name Inspection Facility Address List all STC installed on the airplane
ATTACHMENT In the table that follows please provide detailed and dimensioned descriptions of any crack(s). Attach pictures to this form as necessary. INSPECTION RESULTS FORM CONTINUED LEFT OUTBOARD NACELLE FITTING Nacelle Fitting hours since install? Was a crack found Yes/No? Detailed description: (Attach pictures and additional details as necessary) LEFT INBOARD NACELLE FITTING Nacelle Fitting hours since install? Was a crack found Yes/No? Detailed description: (Attach pictures and additional details as necessary) RIGHT INBOARD NACELLE FITTING Nacelle Fitting hours since install? Was a crack found Yes/No? Detailed description: (Attach pictures and additional details as necessary) RIGHT OUTBOARD NACELLE FITTING Nacelle Fitting hours since install? Was a crack found Yes/No? Detailed description: (Attach pictures and additional details as necessary) Send completed form/attachments to Cessna Structures at csstructures@txtav.com
OWNER ADVISORY TITLE NACELLES/PYLONS - NACELLE FITTING INSPECTION TO: Cessna Aircraft Model 402C and 414A Owner REASON Cracks have been discovered on some 5292029 Nacelle Fittings. An undetected crack can cause the nacelle fitting to break which could result in flight instability. COMPLIANCE. This service letter must be accomplished on each nacelle fitting as listed in the table that follows. The time for this document starts on the date of receipt. NOTE: To find the 5292029 Nacelle Fitting Hours, in the airplane logbook, find the airplane flight hours when compliance with Airworthiness Directive (AD) 2005-12-13 by installation of SK402-47 - Lower Front Wing Spar Cap Inspection/Modification. Take the current airplane flight hours and subtract the flight hours when SK402-47 was installed; this is the current hours for the nacelle fittings. NOTE: The 5292029 Nacelle Fittings with less than 7,500 flight hours are not subject to this inspection until that nacelle fitting reaches 7,500 flight hours. 5292029 Nacelle Fitting Hours Flight Hours To Comply With Initial Inspection Flight Hours for Recurring Inspection 13,400 and above before further flight every 25 flight hours 12,400-13,399 in the next 25 flight hours every 25 flight hours 11,400-12,399 in the next 50 flight hours every 50 flight hours 10,400-11,399 in the next 100 flight hours every 100 flight hours 7,500-10,399 in the next 200 flight hours every 200 flight hours NOTE: The recurring inspection applies to all nacelle fittings with more than 7,500 flight hours. Once a nacelle fitting is replaced, that nacelle fitting no longer has a requirement for the recurring inspection until it has reached 7,500 flight hours. December 23, 2016 Page 1 of 1 Textron Aviation Customer Service, P.O. Box 7706, Wichita, KS 67277, U.S.A. 1-316-517-5800 This document contains technical data and is subject to U.S. export regulations. This information has been exported from the United States in accordance with export administration regulations. Diversion contrary to U.S. law is prohibited. ECCN: 9E991 COPYRIGHT 2016