AD 57-20-04

final rule

Airworthiness Directives; VICKERS Model 700 Series Aircraft

AD Number
57-20-04
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft landing gear and wheel assembly
Problem area Landing gear

Applicability

TypeManufacturerModelDetails
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.

AI-generated summary from the source AD text. Verify against the official source before acting.

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.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Compliance required as indicated.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Vickers-Armstrongs (Aircraft Limited) Viscount 700 Series Aircraft equipped with 14-inch stroke oleos.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

Landing Gear Retraction Jack

Applicability Source Text

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AD Final Rules - DRS_57-20-04.html
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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Superseded AD: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Superseded By: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

Show stored source text (verify against official source)
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

This site is not affiliated with or endorsed by the FAA. Always verify with official sources.