ALERT SERVICE BULLETIN 407-23-130

1. Prepare the helicopter for maintenance. ASB 407-23-130RA Page 5 of 16 Approved for public release. -NOTE- Clean the lower 4.0 inches (101.6 mm) of the removed cyclic stick assembly with cleaning compound (C-318) before inspection (1, Figure 1). 2. Perform the Pilot Cyclic Control Stick 1200 Hour or 24 Month Inspection (DMC-407- A-67-12-03-00A-281A-A). a. If no crack is found, go to step 4. b. If a crack is found or suspected using the 10X magnifying glass visual inspection, disassemble the cyclic stick assembly by removing the cyclic stick grip assembly. i. Disconnect the wires from connector (BHT-ELEC-SPM, Chapter 5); retain connector for further use (9, Figure 1). ii. Remove screw (5), washers (6) and nut (7). iii. Remove cyclic stick grip (4) and elbow (8) as an assembly from cyclic control stick (1). -NOTE- Applying heat to the stick tube (1, Figure 1) after removal of screw (5) may be required if the cyclic stick grip and elbow assembly (8) is difficult to remove. Pay particular attention to direct heat away for the cyclic stick grip (4). Do not exceed 200°F (93°C). CAUTION When the cyclic stick grip assembly is being removed, ensure that the wire removal is assisted from the connector end to avoid excessive stress on the cyclic stick grip connections. c. Remove the paint and primer with paint remover (C-436) and thoroughly inspect the lower end of the cyclic stick tube using the fluorescent penetrant inspection (FPI) method (BHT-ALL-SPM, Chapter 6). d. If cracks are found, accomplish PART II prior to next flight or replace the cracked cyclic stick tube assembly with a serviceable part meeting the intent of the bulletin. ASB 407-23-130RA Page 6 of 16 Approved for public release. i. The following inspection criteria apply to a cracked cyclic tube stick assembly eligible for the accomplishment of PART II: 1. Cracks that extend beyond the edges of the slot are not permitted (Figure 2). 2. Cracked slot lengths longer than 0.791 inch (20.09 mm) are not permitted. ii. If the crack length in the cyclic stick assembly exceeds the criteria of step 2.d.(i), the cyclic stick tube assembly will be considered unserviceable and must be replaced by a serviceable cyclic stick tube assembly meeting the intent of this bulletin prior to next flight. 3. Customers finding a cracked cyclic stick tube assembly must send an email to Bell Product Support Engineering at productsupport@bellflight.com with the following information. a. Subject Line: Helicopter model, serial number and ASB number. Example email subject line: 407 (53001) – ASB 407-23-130RA b. The email shall include the following information: (1) Total time in-service. (2) Cyclic stick tube part number. Ex: 206-001-342-101. (3) Clear in-focus pictures of the damaged cyclic stick tube assembly. 4. If no cracks are found, thoroughly clean the cyclic stick tube with water and mild detergent (C-318) to completely remove residual penetrant and developer. a. Dry the cyclic stick assembly completely. b. Restore removed primer (C-204) and organic finish with polyurethane coating (C-245) before installation of stick into pivot assembly (BHT-ALL-SPM, Chapter 4). 5. If the cyclic stick assembly was disassembled, reinstall cyclic stick grip and wiring harness as follows: ASB 407-23-130RA Page 7 of 16 Approved for public release. a. Route the wires through the tube assembly (1, Figure 1). b. Install the cyclic stick grip (4) and elbow (8) as an assembly. c. Secure the elbow (8) into the cyclic stick tube (1) with screw (5), washers (6) and nut (7). d. Insert wires in connector (9) (BHT-ELEC-SPM Chapter 5). 6. Install the pilot cyclic control stick assembly (DMC-407-A-67-12-03-00A-720A-A). 7. Ensure the following revisions of the INTERIOR AND PRESTART CHECK are inserted in the applicable Flight Manual (RFM): a. BHT-407-FM-1, 22 SEP 2022 Rev. 22 b. BHT-407-FM-2, 22 SEP 2022 Rev. 17 c. BHT-407-FM-3, 22 SEP 2022 Rev. 9 8. Make an entry in the helicopter logbook and historical service records indicating compliance with PART I of this Alert Service Bulletin. PART II: Pilot cyclic stick assembly stop-drill repair 1. For cyclic stick tubes with cracks in the slotted area not exceeding the limits of Figure 2, carry out the following stop drill procedure: -NOTE- The maximum repairable crack length that can be stop drilled cannot be beyond the outside edge of the slot (Figure 2). The pilot hole for the stop drill must be in the full thickness of the tube, centered along the centerline of the slot and no further than 0.010 inch (.25 mm) from the edge of the slot (Figure 3, Sheet 1 of 2). a. Use an automatic center punch to mark the edge of the slot (Figure 3, Sheet 1 of 2). ASB 407-23-130RA Page 8 of 16 Approved for public release. CAUTION The location and orientation of the stop drill is critical. It is important to properly secure the cyclic stick tube prior to drilling to ensure the drill bit is oriented exactly through the centerline of the tube. Preferably the cyclic stick tube should be held in place in a fixing head and drilled on a milling machine. However, since this is not always achievable, Figure 4 shows an example of a drill guide that can be locally manufactured to ensure a clean and well-oriented stop drill hole. Figure 5 shows the installed workaid with the addition of various drill bushings for precise drilling and reaming. b. Locally manufacture a workaid (Figure 4) and procure drill bushings or have the cyclic stick tube stop-drilled in a milling machine. c. Install the drill guide on the cyclic stick tube (Figure 5) and line up with the center punch mark using the smallest drill bushing. d. Secure the drill guide by tightening the nuts only enough to stop the drill guide from moving. Confirm that the drill bushing hole is exactly in line with the center punch mark. Do not over-tighten nuts and bolts to avoid damaging the cyclic stick tube. e. Drill a pilot hole using the smallest drill guide. Use a drill stop to limit the drilling depth to avoid damaging the opposite side of the tube. -NOTE- Stop drill holes must be free of all sharp edges and deburred. f. Increase the stop drill hole diameter until a final ream of 0.1875 inch (4.76 mm) is achieved. Deburr holes. g. Once the stop drill procedure is completed, carry out a fluorescent penetrant inspection (FPI) of the repaired area to ensure the crack is removed and there are no cracks in the stop drill bore. (BHT-ALL-SPM, Chapter 6). h. Thoroughly clean the cyclic stick tube with water and mild detergent (C-318) to completely remove residual penetrant and developer. i. Dry the cyclic stick assembly completely. j. Touch up the repaired area with epoxy polyamide primer (C-204). Refinish the repair as required to match the original finish with polyurethane coating (C-245) (BHT-ALL-SPM, Chapter 4). ASB 407-23-130RA Page 9 of 16 Approved for public release. 2. The repaired cyclic stick tube assembly must be identified as follows: a. Identify the lower part of the cyclic stick tube directly above the pivot assembly by hand marking or stencil marking part number 206-001-342-101FM with white or silver lettering. The size of the alpha-numeric lettering must be approximately 0.25 inch (6.35 mm) -in height. 3. Reinstall cyclic stick grip and wiring harness as follows: i. Route the wires through the tube assembly (1, Figure 1). ii. Install the cyclic stick grip (4) and elbow (8) as an assembly. iii. Secure the elbow (8) into the cyclic stick tube (1) with screw (5), washers (6) and nut (7). 4. Install the pilot cyclic control stick assembly (DMC-407-A-67-12-03-00A-720A-A). 5. Insert wires in connector (9, Figure 1) using Insert/Extract Tool M81969/14-10 and reinstall connector (9). 6. PART III and PART IV of this bulletin are mandatory after completing PART II. 7. Make an entry in the helicopter logbook and historical service records indicating compliance with PART II of this Alert Service Bulletin. PART III: Recurring inspection of cyclic stick tubes 206-001-342-101FM 1. Prepare the helicopter for maintenance. 2. Remove the pilot cyclic control stick (DMC-407-A-67-12-03-00A-520A-A). 3. Clean the lower 4.0 inches (101.6 mm) of the removed cyclic stick assembly (1, Figure 1) with cleaning compound (C-318) before inspection. 4. Inspect the lower 4.0 inches (101.6 mm) of the cyclic stick tube using a 10X magnifying glass. Pay particular attention to the stop-drilled repair area. -NOTE- Cracks in the circled areas of the inner sleeve inboard of the stop-drilled holes as shown in Figure 3 (Sheet 2 of 2) are not cause for rejection. ASB 407-23-130RA Page 10 of 16 Approved for public release. a. If any cracks are found, remove the cyclic stick tube assembly from service and replace with a serviceable cyclic stick tube assembly meeting the intent of this bulletin. b. If no cracks are found, install the cyclic control stick assembly (DMC-407-A-67- 12-03-00A-720A-A). 5. Make an entry in the helicopter logbook and historical service records indicating compliance with PART III of this Alert Service Bulletin. 6. Repeat PART III every 300 flight hours or 6 months, whichever occurs first, until accomplishment of PART IV. PART IV: Replacement of the cyclic stick tube 206-001-342-101FM 1. Prepare the helicopter for maintenance. 2. Remove the cyclic stick tube assembly 206-001-342-101FM that was repaired per PART II of this bulletin. 3. Install a serviceable 206-001-342-101 cyclic stick tube assembly (DMC-407-A-67- 12-03-00A-720A-A). 4. Make an entry in the helicopter logbook and historical service records indicating compliance with PART IV of this Alert Service Bulletin. ASB 407-23-130RA Page 11 of 16 Approved for public release. Figure 1 – Pilot Cyclic Stick Assembly – 10X Magnifying Glass Inspection Area ASB 407-23-130RA Page 12 of 16 Approved for public release. Figure 2- Typical Crack Location and Maximum Repairable Crack Length ASB 407-23-130RA Page 13 of 16 Approved for public release. Figure 3 (Sheet 1 of 2) – Pilot Hole Location for Stop Drill ASB 407-23-130RA Page 14 of 16 Approved for public release. Figure 3 (Sheet 2 of 2) – Stop-Drilled Holes and Inner Sleeve ASB 407-23-130RA Page 15 of 16 Approved for public release. Figure 4 – Drilling Guide V-Blocks (Workaid) ASB 407-23-130RA Page 16 of 16 Approved for public release. Figure 5 – Cyclic Stick Tube with Workaid Installed