AD 2011-20-08

final rule
Data completeness: 70%

Airworthiness Directives; Agusta S.p.A. (Agusta) Model AB139 and AW139 Helicopters

AD Number
2011-20-08
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2011-1036
FR Citation
76 FR 68297

Applicability

TypeManufacturerModelDetails
aircraft Agusta S.p.A. (Agusta) Model AB139 and AW139 Airworthiness Directives; Agusta S.p.A. (Agusta) Model AB139 and AW139 Helicopters

Unsafe Condition

Internal corrosion of the Number 2 Modular Avionic Unit (MAU) circuit card assemblies, which can result from exposure to external moisture via the ventilation duct installation, leading to false indications or misleading data displayed to the flight crew, disengagement of flight director modes, and increased workload that could lead to loss of control.

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

Required Actions

Inspect certain modules and related connectors for corrosion. Clean connectors if corrosion is found. Replace modules with airworthy ones if corrosion is present. Modify the Number 2 Modular Avionic Unit (MAU) ventilation duct to reroute airflow away from the MAU2 cabinet and modules.

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

Compliance Time

Within 30 hours time-in-service or 1 month, whichever occurs first.

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Affected Aircraft

Agusta S.p.A. Model AB139 and AW139 helicopters.

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

Source: Official FAA Source ↗

Retrieved: Apr 6, 2026

Rights: U.S. Government Public Domain

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