AD 86-16-11 L

final rule
Data completeness: 60%

Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 412 Helicopters

AD Number
86-16-11 L
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Bell Helicopter Textron, Inc. 412 Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 412 Helicopters

Unsafe Condition

Failure of the tail rotor control due to cracks in the T/R trunnion housing P/N 212-011-716-1 or axial play in the T/R trunnion, or presence of excess balance washers.

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

Required Actions

Visually inspect the T/R hub assembly P/N 212-011-701-3 per Part I of BHTI ASB 412-86-25. If cracks, axial play, or excess washers exist, perform Part II of the ASB before further flight. Repeat inspections every 20 hours' time in service until paragraph (b) is done. Inspect trunnion bearing housing P/N 212-011-716-1 per Part II of the ASB within 150 hours' time in service or 60 days after AD issue, replacing housings with end web thickness ≤0.059 inches.

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

Compliance Time

Within 20 hours' time in service after receipt of this AD for initial inspection. For paragraph (b), within 150 hours' time in service or within 60 days after the issue date of this AD, whichever occurs first.

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

Affected Aircraft

Bell Helicopter Textron, Inc. Model 412 helicopters, serial numbers 33001 through 33118, 33120 and 33121, certified in any category.

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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