AD 2025-20-09

final rule
Data completeness: 80%

Airworthiness Directives; Airbus SAS Airplanes

AD Number
2025-20-09
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2025-3423
FR Citation
90 FR 53203

Applicability

TypeManufacturerModelDetails
aircraft Airbus SAS Airworthiness Directives; Airbus SAS Airplanes

Unsafe Condition

The combining spill valve (CSV) piston of the engine hydro-mechanical unit (HMU) is slow to close due to piston wear, which can cause an excess of fuel to be sent to the fuel nozzles, resulting in an N1 transient shaft overspeed.

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

Required Actions

Replacing certain HMUs with serviceable HMUs or improved HMUs before reaching a reduced life limit, and prohibiting the installation of affected parts under certain conditions.

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

Airbus SAS Model A350-1041 airplanes equipped with Rolls-Royce Trent XWB-97 engines.

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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