Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and Model C4-605R Variant F Airplanes (Collectively Called A300-600 Series Airplanes); and Airbus Model A310 Series Airplanes

Comment on [Docket No. FAA-2005-22053; Directorate Identifier 2004-NM-74-AD]RIN 2120-AA64 The proposed action requires installation of certain relays in the electronics rack. The precise identification of the relays mandated to be installed is absent from the proposed regulatory action and, we assume, are more specifically identified in the service document. Service bulletins are proprietary documents not generally available to the public so it is not possible to determine precisely which relays are to be installed. Because we cannot determine which relays are to be installed we are unable to identify if any possible alternatives approved under 14 CFR § 21.303 (PMA) exist. We do note that aircraft manufacturers, particularly foreign based manufactures, do not consider the impact of FAR 21.303 in the creation of their service bulletins. Therefore, service documents can and often do create conditions that seek to contravene existing law by mandating the installation of a certain part numbered part to the exclusion of all other parts that may now or in the future exist as FAA approved alternatives. Therefore, this commenter, Modification and Replacement Parts Association (MARPA) requests the following: 1. That the parts to be installed be identified in the AD by manufacturer and model or part number. 2. That the document provide for the possible existence of approved PMA parts by appending the phrase "or FAA-approved equivalent part number" to the part number of the part required to be installed. Jack Buster AD Committee