EASA SIB SAIB-2025-01
Hydraulic Power System - Fatigue Failure of Hydraulic Flexible Hoses
Summary
The Special Airworthiness Information Bulletin (SAIB) 2025-01 issued by the FAA addresses fatigue failure of hydraulic flexible hoses in the wheel wells of the main and nose landing gear on Boeing 757 series airplanes. The bulletin provides information on the issue and recommends maintenance actions to prevent loss of the left hydraulic system. This SAIB is informational and does not mandate regulatory action under 14 CFR part 39.
What Changed
SAIB 2025-01 introduces awareness of fatigue failures in hydraulic flexible hoses on Boeing 757 aircraft and references Boeing Service Letter 757-SL-29-058 for best maintenance practices. It highlights the need for initial and repetitive replacement of older flexible hoses to reduce the risk of hydraulic system failure. This bulletin does not impose mandatory requirements but advises operators to take proactive measures.
Why It Matters
This bulletin is important for aviation professionals because fatigue failure of hydraulic hoses can lead to loss of hydraulic fluid and system functionality, potentially affecting aircraft safety during critical phases like landing. Operators and maintenance organizations must understand the risk to implement preventive maintenance and avoid incidents similar to the April 2022 runway excursion involving a Boeing 757. Compliance teams should monitor this information to ensure continued airworthiness and operational safety.
What To Do
Owners and operators of Boeing 757 series airplanes should review Boeing Service Letter 757-SL-29-058 dated March 11, 2024, and perform the recommended hose replacements as soon as possible. Proactive and repetitive replacement of flexible hydraulic hoses in the main and nose landing gear wheel wells is advised to minimize the risk of hydraulic system failure. No specific compliance deadline is mandated, but early action is recommended.