AD 51-27-01

final rule
Data completeness: 60%

Airworthiness Directives; Bell Model 47 Helicopters

AD Number
51-27-01
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Scotts-Bell 47 Inc 47 Airworthiness Directives; Bell Model 47 Helicopters
aircraft Scotts-Bell 47 Inc 47B Airworthiness Directives; Bell Model 47 Helicopters
aircraft Scotts-Bell 47 Inc 47B3 Airworthiness Directives; Bell Model 47 Helicopters
aircraft Scotts-Bell 47 Inc 47D Airworthiness Directives; Bell Model 47 Helicopters
aircraft Scotts-Bell 47 Inc 47D1 Airworthiness Directives; Bell Model 47 Helicopters
aircraft Scotts-Bell 47 Inc 47E Airworthiness Directives; Bell Model 47 Helicopters
aircraft Scotts-Bell 47 Inc 47G Airworthiness Directives; Bell Model 47 Helicopters
aircraft Scotts-Bell 47 Inc 47G-2 Airworthiness Directives; Bell Model 47 Helicopters
aircraft Scotts-Bell 47 Inc 47G-2A Airworthiness Directives; Bell Model 47 Helicopters
aircraft Scotts-Bell 47 Inc 47G-2A-1 Airworthiness Directives; Bell Model 47 Helicopters

Unsafe Condition

Cracks in the welds of the engine mount assembly P/N 47-612-111-1 or -5 could lead to engine separation.

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

Required Actions

Remove paint from welds and inspect with a 10-power magnifying glass and inspection mirror. Replace the engine mount if cracks are found. Clean welds under the collective pitch disc bracket, inspect for cracks, and apply corrosion preventive. Replace the mount after 600 hours of operation.

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

Compliance Time

Compliance required daily after first 300-hour inspection and at each 600 hours of engine mount service.

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

Affected Aircraft

Scotts-Bell 47 Inc Model 47 helicopters incorporating Engine Mount Assembly P/N 47-612-111-1 or -5.

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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