AD 54-20-02
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Orlando Helicopter Airways, Inc. | Sikorsky Aircraft Corporation | HRS-1/CH-19 | Airworthiness Directives; Sikorsky Model S-55 Helicopters |
| aircraft | Orlando Helicopter Airways, Inc. | Sikorsky Aircraft Corporation | HRS-3/H-19B | Airworthiness Directives; Sikorsky Model S-55 Helicopters |
| aircraft | Orlando Helicopter Airways, Inc. | Sikorsky Aircraft Corporation | S-55 | Airworthiness Directives; Sikorsky Model S-55 Helicopters |
| aircraft | Orlando Helicopter Airways, Inc. | Sikorsky Aircraft Corporation | S-55B | Airworthiness Directives; Sikorsky Model S-55 Helicopters |
| aircraft | Orlando Helicopter Airways, Inc. | Sikorsky Aircraft Corporation | S-55C | Airworthiness Directives; Sikorsky Model S-55 Helicopters |
Unsafe Condition
Cracks in the fore and aft transmission support assemblies (S14-20-2503) may occur, leading to potential failure of the assemblies.
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Required Actions
Inspect daily for cracks in welds and areas within 2 inches of welds on the fore and aft transmission support assemblies without removing them. Remove paint and foreign matter from welds and within 3 inches of welds first. Replace assemblies if cracks are found and protect exposed metal with corrosion preventive. Use 5- to 7-power glass where possible.
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Compliance Time
Compliance required as indicated.
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Affected Aircraft
Sikorsky Model S-55 Helicopters: All serial numbers of HRS-1/CH-19, HRS-3/H-19B, S-55, S-55B, and S-55C models.
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Federal Register Abstract
Support Assembly Cracks
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_54-20-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 54-20-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Model S-55 Helicopters Subject: Support Assembly Cracks Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Orlando Helicopter Airways, Inc. | Sikorsky Aircraft Corporation Model: HRS-1/CH-19 | HRS-3/H-19B | S-55 | S-55B | S-55C Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 54-20-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 54-20-02 SUBJECT HEADING: Airworthiness Directives; Sikorsky Model S-55 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 54-20-02 SIKORSKY: Applies to All Model S-55 Helicopters. Compliance required as indicated. In order that cracks in the fore and aft transmission support assemblies (S14-20-2503) may be detected, these assemblies should be inspected daily, without removing the support assemblies from the helicopter, in accordance with the following procedure: 1. Remove the paint, grease and foreign matter from all welds and from the areas of the tubes within 3 inches of a weld on both upper and lower ends. 2. Inspect for cracks all areas of the tubes within 2 inches of a weld and all welds visually, and, where possible, with the assistance of a 5- to 7-power glass. 3. Assemblies found with a crack should be replaced immediately. 4. Protect the exposed areas of metal with any suitable corrosion preventive. The manufacturer is presently investigating the reasons for the occurrence of such cracks and a permanent repair is expected in the near future which, when incorporated, will make these daily inspections unnecessary. These inspections are in addition to those required by AD 54-16- 01. (Revision C to Sikorsky Information Circular No. 1435-383 covers this same subject.) When transmission support, S14-20-4603, is installed in place of support S14-20-2503, the above inspection may be performed at every intermediate inspection rather than on a daily basis. (Sikorsky Service Information Circular No. 1420-548, dated December 3, 1954, covers the installation instructions.) FOOTER:
Document Text
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AD Final Rules - DRS_54-20-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 54-20-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Model S-55 Helicopters Subject: Support Assembly Cracks Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Orlando Helicopter Airways, Inc. | Sikorsky Aircraft Corporation Model: HRS-1/CH-19 | HRS-3/H-19B | S-55 | S-55B | S-55C Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 54-20-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 54-20-02 SUBJECT HEADING: Airworthiness Directives; Sikorsky Model S-55 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 54-20-02 SIKORSKY: Applies to All Model S-55 Helicopters. Compliance required as indicated. In order that cracks in the fore and aft transmission support assemblies (S14-20-2503) may be detected, these assemblies should be inspected daily, without removing the support assemblies from the helicopter, in accordance with the following procedure: 1. Remove the paint, grease and foreign matter from all welds and from the areas of the tubes within 3 inches of a weld on both upper and lower ends. 2. Inspect for cracks all areas of the tubes within 2 inches of a weld and all welds visually, and, where possible, with the assistance of a 5- to 7-power glass. 3. Assemblies found with a crack should be replaced immediately. 4. Protect the exposed areas of metal with any suitable corrosion preventive. The manufacturer is presently investigating the reasons for the occurrence of such cracks and a permanent repair is expected in the near future which, when incorporated, will make these daily inspections unnecessary. These inspections are in addition to those required by AD 54-16- 01. (Revision C to Sikorsky Information Circular No. 1435-383 covers this same subject.) When transmission support, S14-20-4603, is installed in place of support S14-20-2503, the above inspection may be performed at every intermediate inspection rather than on a daily basis. (Sikorsky Service Information Circular No. 1420-548, dated December 3, 1954, covers the installation instructions.) FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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