AD 53-01-01

final rule
Data completeness: 60%

Airworthiness Directives; Bell Model 47D1 Helicopters

AD Number
53-01-01
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Scotts-Bell 47 Inc 47D1 Airworthiness Directives; Bell Model 47D1 Helicopters

Unsafe Condition

The existing method of mounting the tail rotor gearbox assembly may distort the S10R bearing when tightening the existing clamp, creating a potential failure mode.

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

Required Actions

Install sleeve P/N 47-640-058-1 on assembly 47-640-044-3. Replace clamping ring P/N 47-644-197-1 and clamp P/N 47-640-046-1 with the riveted sleeve.

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

Compliance Time

at next 300-hour teardown inspection but not later than February 28, 1953

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

Affected Aircraft

Scotts-Bell 47 Inc Model 47D1 Helicopters, Serial Numbers 477 to 625, Inclusive

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

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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