Embraer Model EMB-135 and -145 Series Airplanes

Supplementary comment on [Docket No. FAA-2005-20733; Directorate Identifier 2005-NM-004-AD; Amendment 39-14179; AD 2005-14-02] RIN 2120-AA64 FAA has responded to our comment by the following: We do not agree. ADs are issued to provide a means of compliance for operators to ensure that the identified unsafe condition is properly addressed, and the service information referenced in this AD identifies the replacement parts necessary to obtain that compliance. It is impossible for us to foresee all the potential means to correct the unsafe condition, including the availability of replacement parts from sources other than the original manufacturer. This is especially true for yet-to-be designed replacement parts. It is our policy to allow the use of alternative parts, which may exist or may not yet be manufactured, in place of the replacement parts specified in the requirements of this AD only after a review of the design data for those parts to verify that the unsafe condition will not be reintroduced. This review is conducted once we receive a request for an alternative method of compliance. Any operator who would like to use an alternate type of engine fire handle may submit a request for approval of an alternative method of compliance, as specified in paragraph (i) of this AD. The request must include data substantiating that an acceptable level of safety would be maintained by use of the alternate type of engine fire handle. No change to the AD is needed in this regard. Supplementary Comment: The FAA's reply strongly implies that the use of any PMA part to meet the requirements of this AD should be regarded as an Alternative Means of Compliance (AMOC). We disagree. Once a part has been approved under FAR 21.303 it is approved by operation of law for manufacture, installation and use. A PMA part must obtain both design approval, which inherently means compliance with any existing airworthiness directives or known defects as stated in the FAA's reply, and manufacturing approval. Any FAA policy that requires an additional level of approval contravenes higher existing law and is therefore unenforceable on its face. Simply stated, use of a PMA part never requires an AMOC. MARPA has developed a general statement that we believe provides an avenue for regulatory identification of PMA parts used in place of OEM parts, whether known or identified or not, and, at the same time, allows existing or future approved PMA alternatives. This statement acknowledges that most AD's result from type certificate holder issued service requirements and that the majority of type certificate holders, particularly foreign based entities, ignore FAR 21.303. Here is our suggested wording: "The parts designated herein as requiring replacement or modification as well as those designated to be installed shall be interpreted broadly to also include any replacements parts approved under FAR 21.303 for the original equipment parts cited in this action. Nothing in this action prevents or precludes the installation of such alternatively approved parts provided such parts meet current airworthiness standards including those cited in this action." Jack Buster AD Committee