Engine Fuel and Control – Hydro-Mechanical Unit – Replacement / Life Limitation
Superseded. Comply with 2025-0100, which replaces this document.
- Published
- Effective
- Deadline
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators must replace affected hydro-mechanical units before they exceed 11,000 engine hours if replaced between 31 March 2022 and 29 June 2023, or 7,500 engine hours if replaced after 30 June 2023. Installation of affected parts is allowed only if they are serviceable and will be replaced according to the directive's requirements. Compliance must begin by the effective date of 15 March 2022.
Summary
EASA Airworthiness Directive 2022-0040 is an airworthiness directive issued by the European Union Aviation Safety Agency affecting Airbus A350-1041 aeroplanes equipped with Rolls-Royce TRENT XWB-97 engines. It addresses the replacement and life limitation of hydro-mechanical units (HMU) with part number G5020HMU02 to prevent engine transient N1 shaft speed exceedance. The directive aims to ensure continued safe operation by mandating compliance with updated life limits for these engine components.
What changed
EASA Airworthiness Directive 2022-0040 introduces a reduced life limit for affected hydro-mechanical units on the Rolls-Royce TRENT XWB-97 engines installed on Airbus A350-1041 aircraft. It requires replacement of these HMUs before exceeding specified engine hour thresholds depending on the calendar timeframe. The directive also permits installation of serviceable affected parts under defined conditions with mandatory subsequent replacement.
Why it matters
This directive is critical for aviation professionals because it addresses a safety issue related to potential engine thrust loss caused by a slow-closing combining spill valve piston in the HMU, which can lead to engine transient overspeed and rejected take-offs. Operators and maintenance organizations must comply to prevent possible reduced aircraft control during engine failure scenarios. Ensuring compliance helps maintain airworthiness and avoids operational disruptions or safety incidents.
More for Airbus A350
All 224- EASA PAD 26-126Time Limits / Maintenance Checks – Airworthiness Limitations Section / Part 1, Safe Life Airworthiness Limitations Items – AmendmentOct 20, 2026
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