AD 69-08-08
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12D | Airworthiness Directives; Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 Helicopters |
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12L | Airworthiness Directives; Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 Helicopters |
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12L4 | Airworthiness Directives; Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 Helicopters |
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12E | Airworthiness Directives; Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 Helicopters |
| aircraft | Hiller Aviation | Siam Hiller Holdings, Inc. | UH-12E-L | Airworthiness Directives; Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 Helicopters |
Unsafe Condition
Fatigue failures of the tail rotor yoke, P/N 55046 and P/N 55046-5.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Conduct a magnetic-particle inspection and measure the tail rotor yoke fillet radius within 10 hours time in service after the effective date. If a crack is found or the fillet radius is less than 0.030 inches, remove the yoke from service. For fillet radii between 0.030 and 0.050 inches, conduct subsequent inspections every 50 hours and remove the yoke within 250 hours. Ensure replacement yokes have a fillet radius of at least 0.050 inches.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 10 hours time in service after the effective date of this AD
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Affected Aircraft
Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L, and UH-12L4 helicopters with P/N 55046 and P/N 55046-5 tail rotor yokes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Tail Rotor Yoke
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_69-08-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 69-08-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 Helicopters Subject: Tail Rotor Yoke Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 04/23/1969 Make: Hiller Aviation | Siam Hiller Holdings, Inc. Model: UH-12D | UH-12L | UH-12L4 | UH-12E | UH-12E-L 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: 69-08-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-753 AD NUMBER: 69-08-08 SUBJECT HEADING: Airworthiness Directives; Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 Helicopters ACTION: SUMMARY: DATES: Effective April 23, 1969. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 69-08-08 FAIRCHILD HILLER: Amdt. 39-753. Applies to UH-12D, UH-12E, UH- 12E-L, UH-12L and UH-12L4 type helicopters certified in all categories, with P/N 55046 and P/N 55046-5 tail rotor yokes. Compliance required as indicated. To prevent fatigue failures of the tail rotor yoke, P/N 55046 and P/N 55046-5 accomplish the following: (a) Within the next 10 hours time in service after the effective date of this AD, unless already accomplished, conduct a magnetic-particle inspection and a measurement of the tail rotor yoke fillet radius as shown in Figure 1 in Fairchild Hiller Service Letters SL-UH-12L- 55-1 and SL-UH-12D thru G-55-1 dated March 20, 1969. (1) If a crack is found, or if the measured fillet radius is less than 0.030 inches, remove the tail rotor yoke from service prior to further flight. (2) If the measured fillet radius is 0.030 inches or larger but less than 0.050 inches, the yoke may continue in service provided that magnetic-particle inspections are conducted after the inspection required in paragraph (a) at intervals not to exceed 50 hours time in service from the last inspection. Remove cracked yokes from service prior to further flight. Remove from service tail rotor yokes having a fillet radius 0.030 inches or larger but less than 0.050 inches within 250 hours time in service from the effective date of this AD. The service life limit of 2500 hours for the tail rotor yokes of UH-12E-L, UH-12L and UH-12L4 helicopters must not be exceeded. (b) Replacement parts must be tail rotor yokes having a fillet radius of at least 0.050 inches. This amendment is effective April 23, 1969. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_69-08-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 69-08-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 Helicopters Subject: Tail Rotor Yoke Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 04/23/1969 Make: Hiller Aviation | Siam Hiller Holdings, Inc. Model: UH-12D | UH-12L | UH-12L4 | UH-12E | UH-12E-L 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: 69-08-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-753 AD NUMBER: 69-08-08 SUBJECT HEADING: Airworthiness Directives; Fairchild-Hiller Models UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 Helicopters ACTION: SUMMARY: DATES: Effective April 23, 1969. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 69-08-08 FAIRCHILD HILLER: Amdt. 39-753. Applies to UH-12D, UH-12E, UH- 12E-L, UH-12L and UH-12L4 type helicopters certified in all categories, with P/N 55046 and P/N 55046-5 tail rotor yokes. Compliance required as indicated. To prevent fatigue failures of the tail rotor yoke, P/N 55046 and P/N 55046-5 accomplish the following: (a) Within the next 10 hours time in service after the effective date of this AD, unless already accomplished, conduct a magnetic-particle inspection and a measurement of the tail rotor yoke fillet radius as shown in Figure 1 in Fairchild Hiller Service Letters SL-UH-12L- 55-1 and SL-UH-12D thru G-55-1 dated March 20, 1969. (1) If a crack is found, or if the measured fillet radius is less than 0.030 inches, remove the tail rotor yoke from service prior to further flight. (2) If the measured fillet radius is 0.030 inches or larger but less than 0.050 inches, the yoke may continue in service provided that magnetic-particle inspections are conducted after the inspection required in paragraph (a) at intervals not to exceed 50 hours time in service from the last inspection. Remove cracked yokes from service prior to further flight. Remove from service tail rotor yokes having a fillet radius 0.030 inches or larger but less than 0.050 inches within 250 hours time in service from the effective date of this AD. The service life limit of 2500 hours for the tail rotor yokes of UH-12E-L, UH-12L and UH-12L4 helicopters must not be exceeded. (b) Replacement parts must be tail rotor yokes having a fillet radius of at least 0.050 inches. This amendment is effective April 23, 1969. FOOTER:
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