EASA AD BR-2021-12-01
Doors - Ram Air Turbine Compartment Door Seal - Replacement
Summary
Brazilian Airworthiness Directive AD No. 2021-12-01 is a regulatory document issued by the Agência Nacional de Aviação Civil (ANAC) addressing the replacement of the Ram Air Turbine (RAT) compartment door seal on Embraer S.A. model EMB-545 and EMB-550 airplanes. The directive mandates compliance with Embraer Service Bulletin N. 550-52-0005, revision 01, dated May 22, 2018. It applies to all affected aircraft registered in Brazil and aims to ensure continued airworthiness and safety.
What Changed
This new airworthiness directive introduces a mandatory replacement of the RAT compartment door seal to prevent seal peeling and interference with the RAT rotor. It requires operators to replace the seal with the same part number 550-04725-901 within specified flight hours or time limits. The directive also provides credit for previous compliant actions and allows for alternative methods of compliance if approved by ANAC.
Why It Matters
This directive is critical for aviation professionals because the peeling of the RAT compartment door seal can cause loss of RAT function, which is essential for emergency electrical power and flight control. Failure to comply could lead to compromised aircraft controllability during electrical emergencies, posing serious safety risks. Operators, maintenance organizations, and compliance teams must ensure timely adherence to maintain aircraft safety and regulatory compliance.
What To Do
Operators of Embraer EMB-545 and EMB-550 airplanes must replace the RAT compartment door seal before accumulating 600 flight hours or within 12 months from the effective date of December 15, 2021, whichever occurs first. The replacement must follow the procedures in Embraer Service Bulletin N. 550-52-0005, revision 01, including a 24-hour cure time before RAT retraction. Compliance must be recorded in the maintenance logbook, and alternative compliance methods require ANAC approval.
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