ALERT SERVICE BULLETIN UH-1H-II-26-38

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ASB UH-1H-II-26-38 Page 1 of 7 Approved for public release. ALERT SERVICE BULLETIN UH-1H-II-26-38 20 May 2026 MODEL AFFECTED: UH-1H-II SUBJECT: COUPLING 204-040-603-007, -009 and -011, INSPECTION OF HELICOPTERS AFFECTED: ALL UH-1H-II PARTS AFFECTED: Part Number 204-040-603-007 Serial Numbers RGFS 000001 through RGFS 000068. Part Number 204-040-603-009 Serial numbers RGFS000007 through RGFS 000900. Part Number 204-040-603-011 Serial Numbers RGFS 000003 through RGFS 000365. COMPLIANCE: PART I: No later than 600 flight hours or 12 months whichever comes first after the release date of this bulletin. Part II: No later than 90 days after accomplishment of PART I. DESCRIPTION: Some 204-040-603-007, -009 and -011 tail rotor drive inner couplings may have been delivered with corrosion damage on the cadmium-plated surfaces as illustrated in Figure 1 of the Accomplishment Instructions. The suspected -007 couplings, listed in the Parts Affected block were manufactured in June 2021. The suspected -009 couplings were manufactured between September 2020 and September 2022 while the suspected -011 couplings were manufactured between November 2020 and August 2021. ASB UH-1H-II-26-38 Page 2 of 7 Approved for public release. PART I of this ASB mandates a one-time inspection for corrosion damage and provides repair limitations if corrosion damage is found. PART II mandates the replacement of affected couplings if corrosion exceeds the repair limits. Applicability of this bulletin to any spare part shall be determined prior to its installation on an affected helicopter. APPROVAL: The engineering design aspects of this bulletin are Bell Engineering CONTACT INFO: For any questions regarding this bulletin, please contact: Military Technical Support Engineering Tel: 1-817-280-3548 / mts-medium@bellflight.com MANPOWER: When accomplished as part of the 600 hours / 12 months inspection and lubrication, no additional man-hour is required to accomplish this bulletin. WARRANTY: There is no warranty credit applicable for parts or labor associated with this bulletin. MATERIAL: Required Material: The following material is required for the accomplishment of this bulletin and may be obtained through your Bell Supply Center. Part Number Nomenclature Qty (Note) 204-040-603-007 204-040-603-009 204-040-603-011 Coupling Coupling Coupling A/R (1) A/R (1) A/R (1) NOTE 1: Required only if the coupling is not repairable. ASB UH-1H-II-26-38 Page 3 of 7 Approved for public release. Consumable Material: The following material is required to accomplish this bulletin, but may not require ordering, depending on the operator’s consumable material stock levels. This material may be obtained through your Bell Supply Center. Part Number Nomenclature Qty (Note) Reference * 204-040-755-005 Lubricant (Tube Pack) A/R C-015 * C-XXX numbers refer to the consumables list in the BHT-ALL-SPM, Standard Practices Manual SPECIAL TOOLS: None required. WEIGHT AND BALANCE: Not affected. ELECTRICAL LOAD DATA: Not affected. REFERENCES: BHT PUB-92-004-23P Illustrated Parts Breakdown BHT PUB-92-004-23 Maintenance Manual BHT-212-CR&O Component Repair and Overhaul Manual PUBLICATIONS AFFECTED: None affected. ACCOMPLISHMENT INSTRUCTIONS: PART I: Inspection of suspected 204-040-603-007, -009 and/or -011 couplings. 1. After reviewing the helicopter service records, if it is confirmed that none of the affected couplings have been installed, no further action is required. Proceed to step 8. 2. If it cannot be confirmed that the installed couplings are unaffected, continue with step 3. ASB UH-1H-II-26-38 Page 4 of 7 Approved for public release. 3. Disassemble the coupling assembly and thoroughly clean the 204-040-603 inner couplings, for inspection (BHT-212-CR&O). 4. With reference to Figure 1, inspect the coupling outside diameter (OD) for presence of corrosion. 5. For couplings with corrosion on more than 10% of the total cadmium plated OD surface: a. If the corrosion depth does not exceed 0.005 inch (0.127 mm) or cannot be felt with a 0.020 inch (0.508 mm) radius probe, remove the coupling from service within the timeframe specified for PART II. b. If the corrosion depth exceeds 0.005 inch (0.127 mm) or can be felt with a 0.020 inch (0.508 mm) radius probe, replace the coupling before the next flight. 6. For couplings with corrosion on less than 10% of the total cadmium-plated OD surface that cannot be removed manually with a white Scotch Brite (or equivalent) pad: a. If the corrosion depth does not exceed 0.005 inch (0.127 mm) or cannot be felt with a 0.020 inch (0.508 mm) radius probe, remove the coupling from service within the timeframe allowed for accomplishment for PART II. b. If the corrosion depth exceeds 0.005 inch (0.127 mm) or can be felt with a 0.020 inch (0.508 mm) radius probe, replace the coupling before the next flight. 7. For couplings with corrosion on less than 10% of the total cadmium-plated OD surface that can be removed manually with a white Scotch Brite pad (or equivalent), remove all corrosion and apply brush cadmium plating to the repaired surface (BHT- ALL-SPM). 8. Make an entry in the helicopter logbook and historical service records indicating findings and compliance with this Alert Service Bulletin. Specify whether PART II requires accomplishment. If the condition described in Step 5b or 6b was identified, note that compliance with PART II has already been accomplished. PART II. Coupling 204-040-603-007, -009 and -011 replacement. 1. Remove and replace affected couplings that exceed the repair limits outlined in PART I (BHT-212-CR&O). 2. Make an entry in the helicopter logbook and historical service records indicating compliance with this Alert Service Bulletin. ASB UH-1H-II-26-38 Page 5 of 7 Approved for public release. ASB UH-1H-II-26-38 Page 6 of 7 Approved for public release. Figure 1 (sheet 1 of 2) - Examples of corrosion on the coupling OD. ASB UH-1H-II-26-38 Page 7 of 7