AD 59-20-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing Defense & Space Group | 44A | Airworthiness Directives; VERTOL Model 44 Series Helicopters |
| aircraft | Boeing Defense & Space Group | 44B | Airworthiness Directives; VERTOL Model 44 Series Helicopters |
Unsafe Condition
Failure of strap P/N 42R1011-1 in the spar weight assembly P/N 42R1009-1 of metal forward rotor blades.
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Required Actions
Inspect straps P/N 42R1011-1 within the next twenty flight hours using Vertol Engineering Order No. 7A. Replace straps immediately if cracks are found; satisfactory straps have a 600-hour retirement life. Install replacement straps P/N 107R1211 to exempt from this AD.
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Compliance Time
within the next twenty hours of flight
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Affected Aircraft
Boeing Defense & Space Group Model 44A and 44B helicopters with metal forward rotor blades using spar weight assembly P/N 42R1009-1 and strap P/N 42R1011-1.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Spar Weight Assembly Straps
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_59-20-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-20-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; VERTOL Model 44 Series Helicopters Subject: Spar Weight Assembly Straps Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Boeing Defense & Space Group Model: 44A | 44B Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 59-20-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-20-01 SUBJECT HEADING: Airworthiness Directives; VERTOL Model 44 Series Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-20-01 VERTOL: Applies to all Model 44 Series Helicopters. Compliance required as indicated. Due to recent failure of a strap, unless already accomplished, all straps P/N 42R1011-1 of spar weight assembly P/N 42R1009-1 in all metal forward rotor blades are to be inspected within the next twenty hours of flight in accordance with Vertol Engineering Order No. 7A (Drawing No. 42R1011). Straps found satisfactory under these inspections are acceptable for 600 hours' retirement life. Straps found with crack indications are to be replaced immediately. When replacement straps P/N 107R1211 are incorporated, the provisions of this directive no longer apply. This supersedes AD 59-11-02. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_59-20-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-20-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; VERTOL Model 44 Series Helicopters Subject: Spar Weight Assembly Straps Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Boeing Defense & Space Group Model: 44A | 44B 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: 59-20-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-20-01 SUBJECT HEADING: Airworthiness Directives; VERTOL Model 44 Series Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-20-01 VERTOL: Applies to all Model 44 Series Helicopters. Compliance required as indicated. Due to recent failure of a strap, unless already accomplished, all straps P/N 42R1011-1 of spar weight assembly P/N 42R1009-1 in all metal forward rotor blades are to be inspected within the next twenty hours of flight in accordance with Vertol Engineering Order No. 7A (Drawing No. 42R1011). Straps found satisfactory under these inspections are acceptable for 600 hours' retirement life. Straps found with crack indications are to be replaced immediately. When replacement straps P/N 107R1211 are incorporated, the provisions of this directive no longer apply. This supersedes AD 59-11-02. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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