Airworthiness DirectiveEASA AD US-2022-23-11

Fuel - Center Wing Tank Fuel Quantity Indicating System - Installation / Check

Published: Dec 8, 2022
Effective: Jan 4, 2023
Deadline: Jan 4, 2023

Boeing 777

AI-generated summary of the official EASA document. Verify against the PDF before acting.

What to do

Affected operators must install the new software or replace the fuel quantity processor unit as specified, perform software version checks, and conduct operational tests according to the directive. The installation of older fuel quantity processor units is prohibited on airplanes that have already received the updated units. Compliance must be achieved by January 4, 2023, with some relief provided for certain airplanes allowing installation of older units within a 30-month compliance window under specific conditions.

Summary

The Federal Aviation Administration's Airworthiness Directive 2022-23-11 addresses certain Boeing Company Model 777 airplanes. It targets discrepancies between the center wing tank fuel quantity indicated by the fuel quantity indicating system and the actual fuel uploaded, which can lead to misleading engine and crew alerts. The directive mandates software updates or replacements for the fuel quantity processor unit to ensure accurate fuel quantity readings.

What changed

This new airworthiness directive requires installing new software in the fuel quantity processor unit or replacing the unit with one containing updated software, depending on the airplane configuration. It also introduces operational checks and software version verification for the fuel quantity processor unit. Additionally, it prohibits installation of certain older fuel quantity processor units on airplanes that have already been upgraded.

Why it matters

This directive is critical for aviation professionals because inaccurate fuel quantity readings can lead to dispatching airplanes with insufficient fuel, risking engine power loss and inability to safely reach the destination or diversion airports. Operators, maintenance, and compliance teams must ensure that fuel quantity systems are reliable to maintain flight safety and regulatory compliance. The directive also addresses parts availability challenges and provides clarifications to avoid unnecessary aircraft grounding.

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