EASA AD US-2021-23-11
Powerplant System - Fuel Flow Meter Bracket Assembly - Replacement
Summary
The Federal Aviation Administration's Airworthiness Directive 2021-23-11 addresses certain Learjet Inc. Model 45 series airplanes, including Learjet 40, 45, 70, and 75. This directive responds to reports of fuel leaks caused by cracked fuel lines between the engine fuel control and the engine fuel flow meter. The AD mandates replacement of the existing fuel flow meter bracket assembly with a redesigned, thicker bracket assembly to mitigate the unsafe condition.
What Changed
This new airworthiness directive introduces a mandatory replacement of the fuel flow meter bracket assembly on affected Learjet Model 45 series airplanes. It also requires operators to report specific maintenance and vibration data to the FAA to assist in monitoring the issue. The AD applies to a broad range of serial numbers, including some previously excluded airplanes not currently in service.
Why It Matters
This AD is critical for aviation professionals as it addresses a potential fuel leak that could lead to an engine installation fire and loss of aircraft control. Operators and maintenance organizations must ensure compliance to maintain aircraft airworthiness and safety. The reporting requirement helps the FAA assess ongoing risks and determine if further regulatory action is necessary.
What To Do
Operators of affected Learjet Model 45 series airplanes must replace the fuel flow meter bracket assembly with the redesigned part by the effective date of January 10, 2022. Additionally, within 60 days after this date, they must submit detailed reports on maintenance actions and recorded engine fan vibration levels to the FAA. Compliance with these requirements is mandatory to address the unsafe condition.
AI-generated summary from official EASA source document. Always verify against the original.