# Beechcraft Mandatory Service Bulletin 28-4127: No revision named - Rights: © Textron Aviation Inc. Filed by the FAA in regulations.gov docket FAA-2014-0771; AD 2014-26-05 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Beechcraft Mandatory Service Bulletin 28-4127](https://openairdocs.org/service-documents/beechcraft/sb-28-4127.md) - Title as filed: MSB 28-4127 - Pages: 21 - PDF: https://openairdocs.org/files/sha256/09/b8/09b87cecd51b1a1a4cabdf8aaacb0b084e30bce405b823265fc2b016061b8769 - Page: https://openairdocs.org/service-documents/beechcraft/sb-28-4127/file/09b87cecd51b ## Text Some pages are 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 1 of 21 SERVICE BULLETIN MANDATORY SB 28-4127Issued: June, 2013 The export of these commodities, technology or software are subject to the U.S. Export Administration Regulations. Diversion contrary to U.S. law is prohibited. For guidance on export control requirements, contact the Commerce Department's Bureau of Export Administration at http://www.bis.doc.gov. Beechcraft Corporation (BC) issues Service Information for the benefit of owners and fixed base operators in the form of two classes of Service Bulletins. The first class, Mandatory Service Bulletins (red border) includes changes, inspection and modifications that could affect safety or crashworthiness. BC also issues Service Bulletins with no red border which are designated as either recommended or optional in the compliance section within the bulletin. In the case of recommended Service Bulletins, BC feels the changes, modifications, improvements or inspections will benefit the owner/operator and although highly recommended, Recommended Service Bulletins are not considered mandatory at the time of issuance. In the case of Optional Service Bulletins, compliance with the changes, modifications, improvements or inspections is at the owner/operator's discretion. Both classes are available on the web at http://pubs.hawkerbeechcraft.com and mailed to: (a) Owners of record on the FAA Aircraft Registration Branch List and the BC Safety of Flight Information (SOFI) List. (b) Those having a publications subscription. Information on Safety of Flight Information (SOFI) or subscription can be obtained through the Beechcraft Corporation Technical Manual Distribution Center (TMDC). As Mandatory Service Bulletins and Service Bulletins are issued, the Service Bulletin Master Index will be updated and available online at http://pubs.beechcraft.com. Warranty will be allowed only when specifically defined in the Service Bulletin and in accordance with BC Warranty Policy. Unless otherwise designated, BC Mandatory Service Bulletins, Service Bulletins and BC Kits are approved for installation on BC airplanes in original or BC modified configurations only. BC Mandatory Service Bulletins, Service Bulletins and Kits may not be compatible with airplanes modified by STC installations or modifications other than BC approved kits. 1. Planning Information A. Effectivity (1) Airplanes Part 1 applies to the following airplanes: Model G58 Baron, Serials TH-2335, TH-2338 through TH-2348, TH-2351 through TH-2359, TH-2362 through TH-2366, TH-2369, and TH-2371. Part 2 applies to the following airp lanes: Model G58 Baron, Serials TH-2336, TH-2337, TH-2349, TH-2350, TH-2360, TH-2361, TH-2367, TH-2368, TH-2370, TH-2372 and TH-2373. If you are no longer in possession of the airplane, please forward this information to the present owner. (2) Spares None. B. Reason This Service Bulletin is being issued to address a pote ntial for fuel leakage. Beec hcraft Corporation has received reports of fuel leaks due to improper installation of fuel system components. Leakage into an area with an ignition source can creat e potential for fire. Sufficient fuel leakage can lead to an imbalance condition, which may affect airplane controllability. C. Description In Part 1, this Service Bulletin provides instructions to in spect, and replace if necessary, left and right fuel system installations at the following locations: • The outboard wet win g interconnect area. • The interconnects for the leading edge inboard fuel cell, the leading edge outboard fuel cell, and the center tank fuel cell. • Fuel plumbing connections in the wheel well and nacelle. In Part 2 , this Service Bulletin provides instructions to ins pect for proper torque on fuel system fittings located in the nacelle. TITLE: FUEL - INSPECTION FOR CONDITION OF WING FUEL SYSTEM ### Page 2 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 2 of 21 MANDATORY D. Compliance An Airworthiness Directive will be requested on the matter covered by this Service Bulletin. Beechcraft Corporation considers this to be a Mandatory Service Bulletin. It must be accomplished no later than 20 flight hours or two months from issuance of this Service Bulletin, whichever occurs first. Until such time as the Service Bulletin has been complied with, reference Safety Communique 332. E. Approval The engineering data contained in this Service Bulletin is FAA approved. Prior to accomplishment, owners/operators of airplanes registered in countries other than the United States shall consult with their local Aviation Regulatory Authority. Incorporation of this Service Bulletin restores the airplane to original Type Design. F. Manpower The following information is for planning purposes only: Estimated man-hours for inspection for Part 1: 30 hours Estimated man-hours for inspection for Part 2: 4 hours Estimated man-hours for installation/rework Part 1 only: 10 hours Suggested number of technicians: 1 The above is an estimate based on experienced, properly equipped tec hnicians complying with this Service Bulletin. Occasionally, after work has started, conditions may be found that could result in additional man-hours. G. Weight and Balance Negligible. It is the responsibility of the owner/operator to maintain compliance with the applicable Airworthiness Regulations. H. Electrical Load Data No change. I. Software Accomplishment Summary Not applicable. J. References Baron 55 and 58 Maintenance Manual, P/N 55-590000-13G5, Chapter 7, Chapter 20, Chapter 28, and Chapter 32; Safety Communique 332. ### Page 3 SERVICE BULLETIN Issued: June, 2013 3 of 21 SB 28-4127 MANDATORY K. Publications Affected It is recommended that a note “See Service Bulletin 28-4127” be made in the following: Appropriate chapter of the applicable Airplane Mainte nance Manual (AMM), Shop Manual, Flight Manual, Flight Manual Supplement, and Illustrated Parts Catalog. L. Interchangeability of Parts Not applicable. M. Warranty Credit Warranty credit for labor and parts to the extent noted under MANPOWER and MATERIAL will be allowed on all airplanes meeting all the following criteria: (1) Airplane owners must have active Standard Warranty coverage and/or an active Beechcraft Maintenance program with applicable Service Bulletin coverage for the subject airplane when the Service Bulletin is issued. (2) Standard Warranty coverage an d/or Beechcraft Maintenance Program with applicable Service Bulletin coverage must be active for the subject airplane on the day the work is accomplished. (3) The work shall be accomplishe d in accordance with the criter ia defined in Paragraph 1.D., COMPLIANCE. (4) The work shall be accomplishe d in accordance with crite ria defined in Paragraph 3, ACCOMPLISHMENT INSTRUCTIONS. (5) The work shall be accomplished at Hawker Beechcraft Services or an Authorized Service Center (ASC) rated to perform work on the specific model of Beechcraft airplane. (6) While work shall be accomplished in accordance with the criteria defined in Paragraph 1.D, COMPLIANCE, warranty coverage offered in this Service Bulletin will expire 12 months from the last day of the month this Service Bulletin is issued. After this date, the owner/operator assumes the responsibility for compliance cost. (7) Claims for compliance with this Service Bulletin (SB) are to be filed as a W3-type claim against SB 28-4127. (8) After the Service Bulletin has been accomplished, a warranty claim must be submitted to Beechcraft within 60 days of the Service Bulletin completion date. Beechcraft Corporation reserves the right to void continued airplane warranty coverage in the area affected by this Service Bulletin until the date the Service Bulletin is accomplished. The owner/operator should contact Hawker Beechcraft Services or an ASC to schedule the warranty work to be accomplished. Hawker Beechcraft Services or an ASC must submit the appropriate paperwork directly to the Beechcraft Warranty Department for warranty consideration. ### Page 4 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 4 of 21 MANDATORY 2. Material Information A. Materials - Price and Availability Contact information: Hawker Beechcraft Parts & Distribution (HBP&D) 10511 East Central Avenue Wichita, KS 67206 USA Phone: 316-676-3100 or 1-888-727-4344 Fax: 316-676-3222 or 316-676-3327 E-mail: HBC_Parts@beechcraft.com B. Industry Support Not applicable. C. Airplanes (1) The following parts required for accomplishment of Part 1 of this Service Bu lletin may be ordered through Hawker Beechcraft Services, an ASC, or HBP&D: Part Number Description Quantity Per Airplane 60-921046-5 Leading Edge Outboard Bladder Bag, Left As Required 60-921046-6 Leading Edge Outboard Bladder Bag, Right As Required 002-920034-9 Leading Edge Inboard Bladder Bag, Left As Required 002-920034-10 Leading Edge Inboard Bladder Bag, Right As Required 58-380003-13 Center Tank Bladder Bag, Left As Required 58-380003-14 Center Tank Bladder Bag, Right As Required 4852SS305 or 52KS3 Clamp 4 or 8* WWD82 Clamp As Required NAS1924-114 or WWD114 Clamp As Required 2F1-3-41366 Flex Hose As Required 60-921047-1 Tube Assembly As Required 002-920020-1 Gasket 6 35-921502 Gasket 4 *Install clamps P/N 4852SS305 or P/N 52KS3 as defined in Paragraph 3 Accomplishment Instructions, Steps (6)(b) and (6)(c). ### Page 5 SERVICE BULLETIN Issued: June, 2013 5 of 21 SB 28-4127 MANDATORY Beechcraft Corporation expressly reserves the ri ght to supersede, cancel and/or declare obsolete, without prior notice, any parts or publications that may be referenced in this Service Bulletin. (2) The following materials may be obtained locally: D. Spares Not applicable. E. Reidentified Parts None. F. Tooling - Price and Availability Not applicable. 3. Accomplishment Instructions This Service Bulletin shall be accomplished as follows: NOTE Should any difficulty be encountered in accomplishing this Service Bulletin, contact Beechcraft Corporation at 1-800-429-5372 or 316-676-3140 for commercial airplanes or contact appropriate headquarters for military airplanes. Observe all Warnings and Cautions contained in the airplane manuals referenced in this Service Bulletin. Whenever any part of th is system is dismantled, adjusted, repaired or renewed, detailed investigation must be made on completion to make sure that distortion, tools, rags or any other loose articles or foreign matter that could impede the free movement and safe operation of the system are not present, and that the systems and installations in the work area are clean. Part Number Description Quantity Per Airplane Polyken 231 or ASTM- D5486, Type IV, Class I Duct Tape As Required ### Page 6 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 6 of 21 MANDATORY A. Airplane Part 1: Model G58 Baron, Serials TH-2335, TH-2338 through TH-2348, TH-2351 through TH-2359, TH-2362 through TH-2366, TH-2369, and TH-2371. At all locations during the incorporation of this Service Bulletin, inspect for the existence of and damage from foreign objects (FOD). All foreign objects shall be removed and any damage shall be addressed in accordance with the Baron Maintenance Manual. (1) Remove all power from the airplane and disconnect the battery. Display warning notices prohibiting reconnection of airplane electrical power. Review fuel handling and fuel cell maintenance procedures warnings contained in Baron Maintenance Manual, Chapter 28. (2) Defuel the airplane in accordance with Baro n Maintenance Manual, Chapter 28-00-00-201. NOTE After accomplishing the following procedures on the left side of the airplane, repeat the procedures on the right side of the airplane. (3) Remove lower and upper access panels to enable inspection of the inboard, outboard, and center section fuel cells. Refer to Figure 1. (4) Remove the respective fuel cell doors to gain access to the fuel cell bladders. These doors are located behind access panels removed in Step (3). (5) Remove the exhaust heat shield s to enable access to fuel cell. Refer to Figure 1. Inspection at Outboard Wet Wing Interconnect Area Inspect for the existence of and damage from foreign objects. All foreign objects shall be removed and any damage shall be addressed. (6) Locate tube assembly, P/N 60 -921047-1, and the attached flex hose, P/N 2F1-3-41366, at the outboard wet wing interconnect area. Refer to Figure 2. Remove clamps, P/N 52KS3 or P/N 4852SS305, that are attached to flex hose P/N 2F1-3-41366. Remove the flex hose, P/N 2F1-3-41366 from the airplane. Refer to Figur e 2. Inspect for and remove any debris (FOD). Inspect for signs of damage (deformity that might prevent proper sealing) to the tube assembly, P/N 60-921047-1, or the flex hose (such as cuts or scarring) P/N 2F1-3-41366, and accomplish the following: ### Page 7 SERVICE BULLETIN Issued: June, 2013 7 of 21 SB 28-4127 MANDATORY (a) If tube assembly, P/N 60-921047-1, is deformed, thereby preventing proper sealing, remove the tube assembly and install new tube assembly, P/N 60-921047-1. NOTE In the following Steps (6)(b) and (6)(c), it is permissible to install a second clamp at each end of the installed flex hose to ensure a complete seal. The additional clamp must be clocked 90 degrees from the original. (b) If no damage (such as cuts or scarring) exists to the inside sealing surface of the existing flex hose, install the flex hose and one (1) or two (2) new clamps P/N 52KS3 or P/N 4852SS305, as needed, at each end of the hose. Torque to 20-25 inch-pounds. (c) If damage (such as cuts or scarring) exists to the inside sealing surface of the existing flex hose, install new flex hose P/N 2F1-3-41366, and one (1) or two (2) new clamps, P/N 52KS3 or P/N 4852SS305, as needed, at each end of the hose. Torque to 20-25 inch-pounds. (d) Install any access panels that were removed. Inspection at Three Fuel Cells Inspect for the existence of and damage from foreign objects. All foreign objects shall be removed and any damage shall be addressed in accordance with the Baron Maintenance Manual. Only slight force shall be applied to the nipple base during the following steps. Damage to the bladder could occur if too much force is used. (7) Use Figure 3, Figure 4, and Figure 5 to accomplish the following on the leading edge inboard bladder, the leading edge outboard bladder, and the center tank bladder: (a) Locate each of the two (2) P/ N 002-920012-53 inboard (2-inch outside diameter) interconnect tubes, and one (1) P/N 002-920012-51 outboard interconnect tube (3-inch outside diameter) that connect the center tank fuel bladder to the leading edge inboard and outboard bladders. (b) Accomplish the following on the two (2) P/N 002-9 20012-53 inboard (2-inch outside diameter) interconnect tubes, and one (1) P/N 002-920012-51 outboard interconnect tube (3-inch outside diameter) that connect the cent er tank fuel bladder to the le ading edge inboard and outboard bladders: Use an explosion-proof flashlight that meets criteria of MIL-F-3747, Type II or III, Style 1 or 2. ### Page 8 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 8 of 21 MANDATORY (i) Using a (non-explosive) borescope and/or flashlight and mirror, visu ally inspect each fuel bladder interconnect nipple base reinforcement area for separation from bladder wall. Refer to Figure 5. If any degree of separation is noted, remove and replace fuel bladder. If no separation is noted, continue to next step. (ii) The purpose of this step is to verify interconnect tube position relative to the spar. If the interconnect tube is not correctly positioned, unintended loads could be induced on the bladder. Remove the center tank fuel bladder nipple and clamps from each interconnect tube. Apply forward pressure to the aft side of each interconnect tube. If the interconnect tube(s) are installed correctly the tube bead should come against the spar and not continue into the leading edge fuel cell area (See Figure 4). If the interconnect tube is not installed correctly remove the interconnect tube and install correctly per Figure 4. If the tube is installed correctly continue to next step. (iii) Along the lower accessible areas of the fuel bay liners, use a borescope to verify that duct tape is installed over rivets and sheet metal edges, and that no foreign objects are present. If any foreign objects exist or tape is found missing from edges, verify that no damage exists to the bladder. Install tape, if missing, over defined areas. (iv) The purpose of this step is to verify that the bladder is positioned tight against the spar. If the bladder is not tight against and supported by the spar, unintended loads could be induced on the bladder. Hold forward pressure on the aft side of the interconnect tube(s), access the forward side of the interconnect tubes in the inboard and outboard leading edge bladders and ensure that the leading edge inboard and outboard fuel cells, at each interconnect tube, are tight against the forward side of the spar. If not tight, reposition nipple, ensuring it is tight against the forward face of the spar. (v) Reinstall center tank nipples to interconnec t tubes and ensure that the bladder is tight against the aft face of the fuel bay liner. (vi) Install new clamps P/N WWD82, as applicable , to interconnect tube, P/N 002-920012-53. Ensure that the clamps are torqued to 30-35 inch-pounds. Install new clamps, P/N WWD114 (or equivalent P/N NAS1924-114), as applicable, to interconnect tube, P/N 002-920012-51. Ensure that the clamps are torqued to 35-40 inch-pounds. (c) Ensure that the hanger snap clips are properly fastened on the top of each fuel bladder. (d) Install the respective fuel cell doors, using new gaskets, P/N 002-920020-1 (Quantity 3 per wing) and P/N 35-921502 (Quantity 2 per wing). Install fuel access panels. Install any other access panels that were removed to gain access to the three fuel cells. Note: Do not install exhaust heat shields at this time. Inspection of Wheel Well and Nacelle Area Inspect for the existence of and damage from foreign objects. All foreign objects shall be removed and any damage shall be addressed in accordance with the Baron Maintenance Manual. ### Page 9 SERVICE BULLETIN Issued: June, 2013 9 of 21 SB 28-4127 MANDATORY (8) Reconnect the airplane ba ttery and restore power. (9) Jack the airplane in accord ance with Baron Maintenance Manual, Chapter 07-10-00-201. (10) Partially retract the landing ge ar to allow inboard gear doors to fully open. Refer to Baron Maintenance Manual, Chapter 32. (11) Remove all power from the ai rplane and disconnect the battery. NOTE The following Steps (12) through (14) apply to the left and right side of the airplane. Step (15) applies to the left side of the airpl ane. Step (16) applies to the right side of the airplane. (12) In the wheel well area depicted in general location Figure 6, verify torque on all fittings per Baron Maintenance Manual, Chapter 20-10-00. (13) Gain access to four (4) B-nuts in the lower nacelle area, between the aft engine firewall and leading edge fuel bay. Refer to Figure 7. Verify that these four (4) B-nuts are torqued per Baron Maintenance Manual, Chapter 20-10-00. (14) Locate the inboard lower nacelle fairing. Remove the fairing to expose the manifold pressure transducer. Refer to Figure 8. One (1) B-nut is located at each end of the tube that runs from the transducer to the firewall. Verify that each B-nut is torqued per Baron Maintenance Manual, Chapter 20-10-00. (15) Refer to Figure 9, Sheets 1 a nd 2. Gain access to the left upper nacelle area. Verify that eight (8) B-nuts are torqued per Baron Maintenance Manual, Chapter 20-10-00. (16) Refer to Figure 10 and gain access to the right up per nacelle area. Verify that two (2) B-nuts are torqued per Baron Maintenance Manual, Chapter 20-10-00. (17) Reconnect the airplane battery and restore power. (18) Perform an electrical retraction and extension of the main landing gear to verify proper operation of the landing gear. (19) Ensure that the landing gear is in the full down position. Check to be sure that all gears are in the down and locked position. Refer to Baron Maintenance Manual, Chapter 32. (20) Remove the airplane from jacks. Final Check (21) Fully fuel the airplane in accordance with the Baron Maintenance Manual, Chapter 28-00-00-201. A minimum of four hours after fueling the airplane, check for leaks. (22) Leak check all fittings verified in Steps (12) through (16) with power applied and boost pump selected to the High position. (23) Install any access covers that were removed in Steps (12) through (16), inc luding the exhaust heat shield, and verify that all access panels are installed. (24) Ensure all work areas are clean and clea r of tools and miscellaneous items of equipment. (25) Return airplane to service. ### Page 10 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 10 of 21 MANDATORY Part 2: Model G58 Baron, Serials TH-2336, TH-2337, TH-2349, TH-2350, TH-2360, TH-2361, TH-2367, TH-2368, TH-2370, TH-2372 and TH-2373. (1) Remove all power from the airplane and disconnec t the battery. Display warning notices prohibiting reconnection of airplane electrical power. NOTE The following Steps (2) through (4) apply to the left and right side of the airplane. Step (5) applies to the left side of the airplane. Step (6) applies to the right side of the airplane. (2) Remove the exhaust heat shields to enable access to the aft portion of the nacelle. Refer to Figure 1. (3) Locate four (4) B-nuts in t he lower nacelle area, between the aft engine firewall and leading edge fuel bay. Refer to Figure 7. Verify that these four (4) B-nuts are torq ued per Baron Maintenance Manual, Chapter 20-10-00. (4) Locate the inboard lo wer nacelle fairing. Remove the fairing to ex pose the manifold pressure transducer. Refer to Figure 8. One (1) B-nut is located at each end of the t ube that runs from the transducer to the firewall. Verify that each B-nut is torqued per Baron Maintenance Manual, Chapter 20-10-00. (5) Refer to Figure 9, Sheets 1 and 2. Gain access to the left upper nacelle area. Verify that eight (8) B-nuts are torqued per Baron Maintenance Manual, Chapter 20-10-00. (6) Refer to Figure 10 and gain access to the right upper nacelle area. Verify that two (2) B-nuts are torqued per Baron Maintenance Manual, Chapter 20-10-00. (7) Reconnect the airplane battery and restore power. (8) Leak check all fittings verified in Steps (3) thro ugh (6) with power applied and boost pump selected to the High position. (9) Install any access covers that were removed in Steps (2) through (6). (10) Ensure all work areas are c lean and clear of tools and miscellaneous items of equipment. (11) Return airplane to service. B. Spares Not applicable. C. Record of Compliance Upon completion of this Service Bulletin, make an appropriate maintenance record entry. ### Page 11 SERVICE BULLETIN Issued: June, 2013 11 of 21 SB 28-4127 MANDATORY B412706.AI LOWER ACCESS PANELS UPPER ACCESS PANEL LOCATIONS HEAT SHIELD SHOWN REMOVED FUEL ACCESS Access Panel Locations Figure 1 ### Page 12 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 12 of 21 MANDATORY A DETAIL A B412702.AI MAIN SPAR FACE MAIN SPAR FACE P/N 2F1-3-41366 FLEX HOSE - 1 EACH P/N 52KS3 OR P/N 4852SS305 CLAMP, AS DEFINED IN PARAGRAPH 3 ACCOMPLISHMENT INSTRUCTIONS, STEPS (6)(b) AND (6)(c). P/N 60-921047-1 TUBE ASSEMBLY CENTER TANK FUEL BLADDER LEADING EDGE OUTBOARD BLADDER LEADING EDGE INBOARD BLADDER WET WING (LEFT WING SHOWN, RIGHT OPPOSITE) Inspection at Outboard Wet Wing Interconnect Area Figure 2 ### Page 13 SERVICE BULLETIN Issued: June, 2013 13 of 21 SB 28-4127 MANDATORY B412703.AI CENTER TANK FUEL BLADDER LEADING EDGE OUTBOARD BLADDER LEADING EDGE INBOARD BLADDER WET WING P/N 002-920012-53 INBOARD INTERCONNECT TUBE WWD82 CLAMP (4 EACH - LEFT AND RIGHT) P/N 002-920012-51 OUTBOARD INTERCONNECT TUBE WWD114 OR NAS1924-114 CLAMP (2 EACH - LEFT AND RIGHT) (LEFT WING SHOWN, RIGHT OPPOSITE) Inspection at Three Fuel Cells Figure 3 ### Page 14 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 14 of 21 MANDATORY B412704.AI THE MIDDLE BEAD OF THE INTERCONNECT TUBE SHOULD BE ON THE AFT SIDE OF THE SPAR. THE INTERCONNECT TUBE SHOULD BE STICKING OUT OF THE NIPPLE ON BOTH SIDES FOR THE MID-BOARD AND INBOARD TUBES. THE OUTBOARD TUBE SHOULD BE FLUSH OR SLIGHTLY IN OR OUT DEPENDING ON TOLERANCES. VIEW SHOWING THE MIDDLE BEAD OF THE P/N 002-920012-51 OR -53 INTERCONNECT TUBE LOCATED ON THE AFT SIDE OF THE SPAR. BEAD SHOULD BE LOCATED FIRMLY AGAINST SPAR TO ALLOW PROPER FIT AT FUEL CELL INSTALLATION. FWD A B B A FOR THE -51 2.60 INCHES FOR THE -53 3.00 INCHES FOR THE -51 2.90 INCHES FOR THE -53 4.80 INCHES SPAR FUEL BAY LINER (REFERENCE DIMENSIONS ONLY) Bladder Installation Requirements Figure 4 ### Page 15 (OCR) Beechcraft MANDATORY SERVICE BULLETIN NIPPLE FLANGE SEPARATION AND DAMAGE B412707.AI Nipple Flange Separation and Damage Figure 5 Issued: June, 2013 SB 28-4127 15 of 21 ### Page 16 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 16 of 21 MANDATORY B412705.AINACELLE WHEEL WELLVIEW LOOKING FORWARD(LEFT SHOWN, RIGHT OPPOSITE) L NACELLE 70.340 W.S. 31.750 C Nacelle and Wheel Well Figure 6 ### Page 17 SERVICE BULLETIN Issued: June, 2013 17 of 21 SB 28-4127 MANDATORY B412708.AI DETAIL VIEW - LOOKING UP AT B-NUT LOCATION - INBOARD SIDE DETAIL VIEW OF INBOARD SIDE B-NUT LOCATION - LOOKING UP AND INBOARD DETAIL VIEW - LOOKING UP AT B-NUT LOCATION - INBOARD SIDE GENERAL LOCATIONAL VIEW - LOOKING UP AND INBOARD AT RIGHT NACELLE FWD INBD B-Nut Locations in Right Nacelle Figure 7 ### Page 18 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 18 of 21 MANDATORY B412709.AI DETAIL VIEW - LOOKING OUTBOARD AT INBOARD SIDE MANIFOLD PRESSURE TRANSDUCER DETAIL VIEW - B-NUT LOCATION - FORWARD OF LEADING EDGE FUEL BAY GENERAL LOCATIONAL VIEW FWD INBD Nacelle B-Nut Locations at Manifold Pressure Transducer Figure 8 ### Page 19 (OCR) Beechcraft MANDATORY SERVICE BULLETIN GENERAL LOCATIONAL VIEW - LOOKING FORWARD AT LEFT NACELLE ACCESS - PANELS REMOVED DETAIL VIEW - LOOKING INBOARD AT LEFT NACELLE ACCESS *14-2380 N * DETAIL VIEW - LOOKING OUTBOARD AT LEFT SIDE DETAIL VIEW - LOOKING FORWARD AND SLIGHTLY DOWN - LEFT NACELLE B412710.AI Upper Left Nacelle B-Nut Locations Figure 9, Sheet 1 of 2 Issued: June, 2013 SB 28-4127 19 of 21 ### Page 20 SERVICE BULLETIN Issued: June, 2013 SB 28-4127 20 of 21 MANDATORY B412711.AI GENERAL LOCATIONAL VIEW - UPPER LEFT NACELLE DETAIL VIEW - LOOKING FORWARD AND INBOARD AT B-NUT LOCATIONS FWD INBD Upper Left Nacelle B-Nut Locations Figure 9, Sheet 2 of 2 ### Page 21 SERVICE BULLETIN Issued: June, 2013 21 of 21 SB 28-4127 MANDATORY B412712.AI DETAIL VIEW - LOOKING INBOARD DETAIL VIEW - LOOKING INBOARD GENERAL LOCATIONAL VIEW - LOOKING FORWARD AND OUTBOARD FWD OUTBD B-Nut Locations in Upper Right Nacelle Figure 10 --- 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.