AD 70-18-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | FH1100 Manufacturing Corporation | 1100 | Airworthiness Directives; Fairchild Hiller Model 1100 Series Helicopters |
Unsafe Condition
Failure of transmission vertical struts and mounts (P/N 24-28030-1 and -2) due to cracks in weld areas.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Strip epoxy paint from weld areas of transmission vertical struts and mounts using commercial paint stripper, dye penetrant inspect weld areas for cracks, replace any cracked parts before further flight, refinish stripped areas with two coats of zinc chromate, and repeat the procedure every 100 flight hours.
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Compliance Time
within the next 25 flight hours of the effective date of this A/D unless already accomplished
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Affected Aircraft
Fairchild Hiller Model 1100 series helicopters certificated in all categories.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Transmission Vertical Status
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_70-18-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 70-18-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Fairchild Hiller Model 1100 Series Helicopters Subject: Transmission Vertical Status Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 09/15/1970 Make: FH1100 Manufacturing Corporation Model: 1100 Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 70-18-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1075 AD NUMBER: 70-18-04 SUBJECT HEADING: Airworthiness Directives; Fairchild Hiller Model 1100 Series Helicopters ACTION: SUMMARY: DATES: Effective September 15, 1970. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 70-18-04 FAIRCHILD HILLER HELICOPTERS: Amdt. 39-1075. Applies to 1100 series helicopters certificated in all categories. Compliance required within the next 25 flight hours of the effective date of this A/D unless already accomplished. To prevent failure of transmission vertical struts and mounts: (1) Strip epoxy paint from weld areas of transmission vertical struts and mounts P/N 24-28030-1 and -2 with commercial paint stripper. (2) With dye penetrant inspect weld areas for cracks. (3) Replace any cracked part prior to further flight. (4) Refinish stripped areas with two coats of zinc chromate. (5) Repeat above procedure at each succeeding 100 flight hours. This amendment is effective September 15, 1970. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_70-18-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 70-18-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Fairchild Hiller Model 1100 Series Helicopters Subject: Transmission Vertical Status Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 09/15/1970 Make: FH1100 Manufacturing Corporation Model: 1100 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: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 70-18-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1075 AD NUMBER: 70-18-04 SUBJECT HEADING: Airworthiness Directives; Fairchild Hiller Model 1100 Series Helicopters ACTION: SUMMARY: DATES: Effective September 15, 1970. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 70-18-04 FAIRCHILD HILLER HELICOPTERS: Amdt. 39-1075. Applies to 1100 series helicopters certificated in all categories. Compliance required within the next 25 flight hours of the effective date of this A/D unless already accomplished. To prevent failure of transmission vertical struts and mounts: (1) Strip epoxy paint from weld areas of transmission vertical struts and mounts P/N 24-28030-1 and -2 with commercial paint stripper. (2) With dye penetrant inspect weld areas for cracks. (3) Replace any cracked part prior to further flight. (4) Refinish stripped areas with two coats of zinc chromate. (5) Repeat above procedure at each succeeding 100 flight hours. This amendment is effective September 15, 1970. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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