AD 57-20-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Vickers-Armstrongs (Aircraft Limited) | Viscount 744 | Airworthiness Directives; VICKERS Model 700 Series Aircraft |
| aircraft | Vickers-Armstrongs (Aircraft Limited) | Viscount 745D | Airworthiness Directives; VICKERS Model 700 Series Aircraft |
Unsafe Condition
Cracks in the trunnion pins and bearing bolts of the main landing gear retraction jack assembly could lead to failure of the landing gear retraction system.
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Required Actions
Replace trunnion fork end P/N 74450-99 and pin P/N 7450-101 at 2,500 flights; replace bearing bolt P/N 74450-103 at 5,000 flights; replace trunnion block P/N 74450-79, pin P/N 74450-81, and bearing bolt P/N 74450-341 or 74450-83 at 7,000 flights. Conduct precautionary visual inspections for cracks on the trunnion at next daily inspection if exceeding 2,500 flights, with replacement required if cracks are found before further flight.
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Compliance Time
Compliance required as indicated.
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Affected Aircraft
Vickers-Armstrongs (Aircraft Limited) Viscount 700 Series Aircraft equipped with 14-inch stroke oleos.
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Federal Register Abstract
Landing Gear Retraction Jack
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_57-20-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 57-20-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; VICKERS Model 700 Series Aircraft Subject: Landing Gear Retraction Jack Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Vickers-Armstrongs (Aircraft Limited) Model: Viscount 744 | Viscount 745D Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 57-20-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 57-20-04 SUBJECT HEADING: Airworthiness Directives; VICKERS Model 700 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 57-20-04 VICKERS: Applies to All Viscount 700 Series Aircraft Equipped With 14-Inch Stroke Oleos. Compliance required as indicated. As a result of investigations and tests by Vickers it has been found necessary to limit the life of the trunnion pins and bearing bolts of the main landing gear retraction jack (cylinder) assembly, right and left, Drawing No. 77450 sheet 7. Accordingly, Vickers-Armstrong insured the following corrective measures with concurrence of the British Air registration Board. The FAA concurs with this action and considers compliance therewith mandatory: 1. At the ram end of the retraction jack, attached to the landing gear actuating lever assembly, replace the trunnion fork end P/N 74450-99 and pin P/N 7450-101, at 2,500 flights; and bearing bolt P/N 74450-103 at 5,000 flights. On aircraft that have exceeded 2,500 flights a precautionary visual inspection for cracks on the trunnion P/N 74450-99 is required at the next daily inspection with particular attention being paid to the flat surfaces. If cracks are found the trunnion and pin and bearing bolt must be replaced before further flight. If no cracks are found, aircraft may continue flying provided the trunnion is visually inspected for cracks at every daily check until replaced. 2. At the retraction jack cylinder end, attached to structure joint assembly, replace the trunnion block P/N 74450-79, pin P/N 74450-81 and bearing bolt P/N 74450-341 or 74450- 83 at 7,000 flights. FOOTER:
Document Text
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AD Final Rules - DRS_57-20-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 57-20-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; VICKERS Model 700 Series Aircraft Subject: Landing Gear Retraction Jack Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Vickers-Armstrongs (Aircraft Limited) Model: Viscount 744 | Viscount 745D Product Type: Aircraft Product Subtype: Large 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: 57-20-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 57-20-04 SUBJECT HEADING: Airworthiness Directives; VICKERS Model 700 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 57-20-04 VICKERS: Applies to All Viscount 700 Series Aircraft Equipped With 14-Inch Stroke Oleos. Compliance required as indicated. As a result of investigations and tests by Vickers it has been found necessary to limit the life of the trunnion pins and bearing bolts of the main landing gear retraction jack (cylinder) assembly, right and left, Drawing No. 77450 sheet 7. Accordingly, Vickers-Armstrong insured the following corrective measures with concurrence of the British Air registration Board. The FAA concurs with this action and considers compliance therewith mandatory: 1. At the ram end of the retraction jack, attached to the landing gear actuating lever assembly, replace the trunnion fork end P/N 74450-99 and pin P/N 7450-101, at 2,500 flights; and bearing bolt P/N 74450-103 at 5,000 flights. On aircraft that have exceeded 2,500 flights a precautionary visual inspection for cracks on the trunnion P/N 74450-99 is required at the next daily inspection with particular attention being paid to the flat surfaces. If cracks are found the trunnion and pin and bearing bolt must be replaced before further flight. If no cracks are found, aircraft may continue flying provided the trunnion is visually inspected for cracks at every daily check until replaced. 2. At the retraction jack cylinder end, attached to structure joint assembly, replace the trunnion block P/N 74450-79, pin P/N 74450-81 and bearing bolt P/N 74450-341 or 74450- 83 at 7,000 flights. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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