EASA AD 26-020 — Landing Gear — Landing Gear Selector Valve — Functional Check
Summary
EASA Airworthiness Directive 26-020 is a proposed directive addressing the landing gear selector valve on ATR 42 and ATR 72 aeroplanes. It applies to specific models including ATR 42-200 through ATR 42-500 and ATR 72-101 through ATR 72-212A, focusing on the functional check of the landing gear selector valve to prevent uncommanded nose landing gear retraction. The directive targets valves with certain part and serial numbers to ensure safe operation.
What Changed
This new proposed airworthiness directive introduces a one-time functional leakage test of the affected landing gear selector valves on specified ATR 42 and ATR 72 aircraft. It requires replacement of any valve found with leakage out of tolerance and mandates reporting of test results to ATR. The directive also clarifies installation rules for serviceable parts and sets compliance timelines based on flight cycles and calendar time.
Why It Matters
This directive is critical for aviation professionals as it addresses a safety risk involving uncommanded nose landing gear retraction, which could lead to loss of landing gear or aircraft control during ground operations or after touchdown. Operators and maintenance organizations must ensure compliance to prevent potential damage or injury. The directive also provides clear instructions for inspection, corrective actions, and reporting, which are essential for maintaining airworthiness and regulatory compliance.
What To Do
Operators of affected ATR 42 and ATR 72 aircraft must perform a leakage test on the landing gear selector valve before it exceeds 5,500 flight cycles or within six months after the directive's effective date, whichever is later, with a minimum of 5,000 flight cycles before testing. If leakage is detected beyond tolerance, the valve must be replaced before the next flight. Test results must be reported to ATR within 30 days of completion. Installation of affected parts is only allowed if they are serviceable according to ATR instructions.