McDonnell Douglas Model DC-10-10 a nd DC-10F Airplanes; Model DC-10-15 Airplanes; Model DC-10-30 and DC-10-30F(KC-10A and KDC-10) Airplanes; Model DC-10-40; DC-10-40F Airplanes: Model MD-10-10f and MD-30F Airplanes; and Model MD-11; MD-11F Airplanes

Comment on [Docket No. FAA-2006-24787; Directorate Identifier 2006-NM-043-AD] RIN 2120-AA64 Paragraph F(2) requires the replacement of defective part numbered part with a "new and improved" part, as follows: (2) Replace any electrical connector having part number (P/N) DC62E24-10SN or FC6DE24-10S of the auxiliary hydraulic pumps at the right wheel well of the MLG with improved electrical connectors having P/N DC62F24-10SN, and do the related investigative action before further flight, by accomplishing all of actions specified in the Accomplishment Instructions of McDonnell Douglas DC-10 Service Bulletin 29-135, dated September 8, 1993. If the auxiliary hydraulic system fails the test, before further flight, repair the auxiliary hydraulic system according to a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. Chapter 29-20-00 of the DC-10 Aircraft Maintenance Manual is one approved method. We suggest and request the language be modified to append the term "or FAA-approved equivalent part number" to the part number mandated to be installed. The addition of these five words, in our opinion, removes any possible conflict with 14 CFR § 21.303 that may be raised with respect to the unmodified text. We refer you to AD 2005-25-07 (2005-CE-15) (DMS 20712) where the FAA responded as follows: Comment Issue: Include Parts Manufacture Approval (PMA) Parts Approved by Identicality in the Replacement Parts What is the commenter's concern? The commenter, the Modification and Replacement Parts Association (MARPA), states: ``The proposed action requires replacing a plastic EMI-RFI filter cover with a metallic cover P/N 390-555015-0001. The problem with requiring the installation of a specific part number to the exclusion of all other part numbers is that such a requirement conflicts with 14 CFR 21.303 (PMA).'' The MARPA requests that the final action include the phrase ``or other FAA-approved equivalent part'' after the part number. What is FAA's response to the concern? We agree with the MARPA. The FAA will add the phrase ``or FAA-approved equivalent part number'', and add language to cover the PMA replacement parts. There is an underlying element of consistency in the law evidenced by the various courts' great focus upon precedent in case law and history of statutory interpretation. When two parallel departments of the same government agency maintain policies and practices that conflict one with the other, indeed even to opposite ends, there needs to evolve a solution that will remove the conflict. Airworthiness directives are legal documents and are therefore interpreted as a matter of law as opposed to fact. This interpretation is bounded by the figurative four corners of the document and such factual elements as intent of the writer or common industry practice are not relevant; generally the document must stand on its own. To harbor an inherent conflict in how an issue is treated is an invitation for the courts to remove that conflict and is so doing invalidate those orders based upon the interpretation found to be defective. A situation to be avoided. We therefore suggest and request that the Transport Airplane Directorate and the Small Airplane Directorate, in a timely manner, agree on how the matter is to be treated. We also note that the publication of incorporated by reference service bulletins in the DMS file on an airworthiness directive is under consideration. We wish to commend this action to lift the decades long "data curtain" on airworthiness directive requirements buried in service documents. Parts purveyors, component repairers and maintenance and repair organizations, not to mention MARPA itself, would greatly benefit from the ready availability of these documents. It would be a very positive step towards greater aviation safety through knowledge. Jack Buster AD Committee