EASA AD 2007-0057R1
Engine — Gas Generator Front Bearing — Modification
Summary
EASA Airworthiness Directive 2007-0057R1 is a regulatory update addressing the ARRIUS 2F engines manufactured by SAFRAN Helicopter Engines, commonly installed on EC 120B helicopters. This directive mandates modifications to the gas generator front bearing to prevent un-commanded in-flight engine shutdowns caused by bearing fractures. The directive ensures continued airworthiness by requiring installation of improved gas generator front bearings.
What Changed
EASA Airworthiness Directive 2007-0057R1 revises the original AD 2007-0057 by excluding engines that have incorporated SAFRAN modification Tf84 from its applicability. It introduces mod Tf84 as an alternative compliance method to the previously required mod Tf12 for the gas generator front bearing modification. This revision reflects updated service bulletin instructions and acknowledges equivalent safety standards provided by mod Tf84.
Why It Matters
This directive is critical for aviation professionals as it addresses a safety issue that could lead to engine failure and emergency autorotation landings on single-engine helicopters. Operators and maintenance organizations must ensure compliance to prevent in-flight shutdowns caused by gas generator front bearing failure. Adhering to this AD maintains regulatory compliance and enhances flight safety for affected aircraft equipped with ARRIUS 2F engines.
What To Do
Operators must modify affected ARRIUS 2F engines by installing the improved gas generator front bearing using either SAFRAN mod Tf12 or mod Tf84. The modification must be completed by 30 April 2008 unless already accomplished. Maintenance teams should follow the instructions in Turboméca MSB No 319 72 4012 or SAFRAN SB 319 72 4084 to comply with this directive.
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