AD 2012-12-10

final rule
Data completeness: 70%

Airworthiness Directives; Agusta S.p.A. Helicopters

AD Number
2012-12-10
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2012-0013
FR Citation
77 FR 37779

Applicability

TypeManufacturerModelDetails
aircraft Agusta S.p.A. Airworthiness Directives; Agusta S.p.A. Helicopters

Unsafe Condition

A potential fault in the overvoltage protection in GCUs currently installed on Model AB139 and AW139 helicopters. This could result in failure of the overvoltage protection of the GCU, degraded performance of the electrical power generation and distribution systems, or fire, and subsequent loss of control of the helicopter.

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

Required Actions

Remove the No. 1 and No. 2 GCU, P/N 1152550-3. Modify the electrical connectors A13P1 and A14P1 by installing wiring to the power distribution panel. Install a No. 1 and No. 2 GCU with P/N 1152550-4 or 1152550-5, ensuring both GCUs have identical part numbers.

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

Compliance Time

Within 6 months from the effective date of the AD.

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

Affected Aircraft

Agusta S.p.A. Model AB139 and AW139 helicopters with a generator control unit (GCU), part-number (P/N) 1152550-3 installed.

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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