AD 99-26-14

final rule
Data completeness: 70%

Airworthiness Directives; Agusta S.p.A. Model AB412 Helicopters

AD Number
99-26-14
Status
final_rule
Effective Date
Product Category
aircraft
Docket
99-SW-63-AD
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Agusta S.p.A. AB412 Airworthiness Directives; Agusta S.p.A. Model AB412 Helicopters
aircraft Agusta S.p.A. AB412 EP Airworthiness Directives; Agusta S.p.A. Model AB412 Helicopters

Unsafe Condition

Fatigue failure of a main rotor yoke (yoke) could result in loss of a main rotor blade and subsequent loss of control of the helicopter due to the yokes being on the low end of the manufacturer’s tolerance for thickness and lacking the desired margin of safety.

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

Required Actions

Remove and replace each main rotor yoke, part number 412-010-101-123 or -127, with an airworthy yoke, part number 412-010-101-129 before further flight. Alternative methods of compliance may be approved by the FAA if they provide an acceptable level of safety.

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

Compliance Time

Before further flight

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

Affected Aircraft

Agusta S.p.A. Model AB412 helicopters with main rotor yoke part numbers 412-010-101-123 or -127 installed, certificated 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

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