AD 77-15-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Enstrom Helicopter Corporation, The | 280C | Airworthiness Directives; Enstrom Model F28C and 280C Helicopters |
| aircraft | Enstrom Helicopter Corporation, The | F-28C | Airworthiness Directives; Enstrom Model F28C and 280C Helicopters |
Unsafe Condition
Fatigue cracking of the tail rotor pitch link retainer assembly (P/N 28-16320) around the circular hub and arm base could result in tail rotor pitch link failure.
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Required Actions
Perform a dye penetrant inspection around the circular hub and arm base of the pitch link retainer assembly P/N 28-16320. Replace the wide chord tail rotor pitch link assembly P/N 28-16320 and two guide bolts P/N 28-16307 with new assembly P/N 28-16325 and guide bolts P/N 28-16324.
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Compliance Time
Before further flight and within ten (10) hours time in service after receipt of the airmail letter.
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Affected Aircraft
Enstrom Models F28C and 280C helicopters with wide chord (4.4 inch) tail rotor blades.
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Federal Register Abstract
Tail Rotor Pitch Link Assembly
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_77-15-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 77-15-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Enstrom Model F28C and 280C Helicopters Subject: Tail Rotor Pitch Link Assembly Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/26/1977 Make: Enstrom Helicopter Corporation, The Model: 280C | F-28C Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 77-15-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2973 AD NUMBER: 77-15-04 SUBJECT HEADING: Airworthiness Directives; Enstrom Model F28C and 280C Helicopters ACTION: SUMMARY: DATES: Effective July 26, 1977. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 77-15-04 ENSTROM: Amendment 39-2973. Applies to Enstrom Models F28C and 280C helicopters with wide chord (4.4 inch) tail rotor blades certificated in all categories. Before further flight perform a dye penetrant inspection around the circular hub including the arm base of the pitch link retainer assembly P/N 28-16320 unless already accomplished in the last ten hours time in service. Within ten (10) hours time in service after the receipt of this airmail letter, unless already accomplished, replace the wide chord tail rotor pitch link assembly P/N 28- 16320 and two (2) guide bolts P/N 28-16307 with a new wide chord tail rotor pitch link retainer assembly P/N 28-16325 and two (2) guide bolts P/N 28-16324. Enstrom Service Directive Bulletin Number 0040 pertains to this same subject. This amendment is effective July 26, 1977, and was effective immediately for all recipients of airmail letters dated June 15, 1977 which contained this amendment. FOOTER:
Document Text
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AD Final Rules - DRS_77-15-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 77-15-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Enstrom Model F28C and 280C Helicopters Subject: Tail Rotor Pitch Link Assembly Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/26/1977 Make: Enstrom Helicopter Corporation, The Model: 280C | F-28C 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: 77-15-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2973 AD NUMBER: 77-15-04 SUBJECT HEADING: Airworthiness Directives; Enstrom Model F28C and 280C Helicopters ACTION: SUMMARY: DATES: Effective July 26, 1977. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 77-15-04 ENSTROM: Amendment 39-2973. Applies to Enstrom Models F28C and 280C helicopters with wide chord (4.4 inch) tail rotor blades certificated in all categories. Before further flight perform a dye penetrant inspection around the circular hub including the arm base of the pitch link retainer assembly P/N 28-16320 unless already accomplished in the last ten hours time in service. Within ten (10) hours time in service after the receipt of this airmail letter, unless already accomplished, replace the wide chord tail rotor pitch link assembly P/N 28- 16320 and two (2) guide bolts P/N 28-16307 with a new wide chord tail rotor pitch link retainer assembly P/N 28-16325 and two (2) guide bolts P/N 28-16324. Enstrom Service Directive Bulletin Number 0040 pertains to this same subject. This amendment is effective July 26, 1977, and was effective immediately for all recipients of airmail letters dated June 15, 1977 which contained this amendment. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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