AD 2025-21-02

final rule
Data completeness: 80%

Airworthiness Directives; The Boeing Company Airplanes

AD Number
2025-21-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2024-2144
FR Citation
90 FR 54555

Applicability

TypeManufacturerModelDetails
aircraft Boeing Company Airworthiness Directives; The Boeing Company Airplanes

Unsafe Condition

high electrical resistance in both transorb modules, which can result in two actuator control electronics (ACEs) being exposed to damaging lightning transient voltages in excess of the qualification levels, potentially inducing erroneous or oscillatory outputs to flight control surfaces and could result in loss of control of the airplane.

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

Required Actions

determining if affected transorb modules are installed, replacing or testing affected transorb modules, and applicable on-condition actions, and replacing affected connectors.

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

The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes.

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

Source: Official FAA Source ↗

Retrieved: Apr 4, 2026

Rights: U.S. Government Public Domain

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