AD 59-17-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Helio Aircraft LLC | H-391B | Airworthiness Directives; Helio Models H-391B and H-395 Aircraft |
| aircraft | Helio Aircraft LLC | H-395 (USAF L-28A or U-10B) | Airworthiness Directives; Helio Models H-391B and H-395 Aircraft |
Unsafe Condition
Cracks around bolt holes and the 2.0-inch diameter lightening hole in the horizontal tail front spar splice plate (P/N 391-020-305) could lead to structural failure.
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Required Actions
Inspect the horizontal tail front spar splice plate for cracks around bolt holes and the 2.0-inch diameter lightening hole. Replace with a 0.063-inch 4130 steel part if cracks are found. If no cracks, inspect every 25 hours until the next 100-hour inspection or October 1, 1959, then replace with steel part.
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Compliance Time
Within the next 10 hours unless already accomplished
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Affected Aircraft
Helio Models H-391B (except serial numbers 093, 094, 098) and H-395 (serial numbers 502 through 510)
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Federal Register Abstract
Horizontal Tail Spar Fitting
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_59-17-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-17-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Helio Models H-391B and H-395 Aircraft Subject: Horizontal Tail Spar Fitting Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Helio Aircraft LLC Model: H-391B | H-395 (USAF L-28A or U-10B) Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 59-17-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-17-05 SUBJECT HEADING: Airworthiness Directives; Helio Models H-391B and H-395 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-17-05 HELIO: Applies to All Model H-391B Aircraft Except Serial Numbers 093, 094, and 098; and Model H-395, Serial Numbers 502 Through 510. Compliance required as indicated. Within the next 10 hours unless already accomplished inspect the horizontal tail front spar splice plate, P/N 391-020-305, for cracks around all bolt holes and the 2.0-inches diameter lightening hole. If cracks are found, the fitting should be replaced with an identically dimensioned part 0.063-inch 4130 steel. If no cracks are found the original aluminum fitting shall be inspected at each 25 hours thereafter until the next 100-hour inspection or October 1, 1959, whichever occurs first, when it must be replaced with a steel part. (Helio Service Bulletin No. 21 covers this subject.) FOOTER:
Document Text
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AD Final Rules - DRS_59-17-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-17-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Helio Models H-391B and H-395 Aircraft Subject: Horizontal Tail Spar Fitting Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Helio Aircraft LLC Model: H-391B | H-395 (USAF L-28A or U-10B) Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 59-17-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-17-05 SUBJECT HEADING: Airworthiness Directives; Helio Models H-391B and H-395 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-17-05 HELIO: Applies to All Model H-391B Aircraft Except Serial Numbers 093, 094, and 098; and Model H-395, Serial Numbers 502 Through 510. Compliance required as indicated. Within the next 10 hours unless already accomplished inspect the horizontal tail front spar splice plate, P/N 391-020-305, for cracks around all bolt holes and the 2.0-inches diameter lightening hole. If cracks are found, the fitting should be replaced with an identically dimensioned part 0.063-inch 4130 steel. If no cracks are found the original aluminum fitting shall be inspected at each 25 hours thereafter until the next 100-hour inspection or October 1, 1959, whichever occurs first, when it must be replaced with a steel part. (Helio Service Bulletin No. 21 covers this subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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