On November 3, 2000, the FAA issued AD 2000-23-04, amendment 39-11974 (65 FR 68076, November 14, 2000), applicable to all Aerospatiale Model ATR42-500 series airplanes, to require revising the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to incorporate life limits for certain items and inspections to detect fatigue cracking in certain structures. That action was prompted by issuance of a new revision of the "Time Limits" section of the ATR42-400/500 Maintenance Planning Document, which specifies new inspections and compliance times for inspection and replacement actions. The actions required by that AD are intended to ensure that fatigue cracking of certain structural elements is detected and corrected; such fatigue cracking could adversely affect the structural integrity of these airplanes. \n\nActions Since Issuance of Previous Rule \n\tSince the issuance of that AD, the FAA notes that we inadvertently did not provideinformation pertaining to the incorporation by reference of certain materials. The incorporation by reference of certain materials allows Federal agencies to comply with the requirement to publish rules in the Federal Register by referring to materials already published elsewhere. The legal effect of incorporation by reference is that the material is treated as if it were published in the Federal Register. This material, like any other properly issued rule, has the force and effect of law. Congress authorized incorporation by reference in the Freedom of Information Act to reduce the volume of material published in the Federal Register and Code of Federal Regulations (CFR). \n\nFAA's Findings \n\tThe FAA has revised AD 2000-23-04 to incorporate by reference the "Time Limits" section of the ATR42-400/500 Maintenance Planning Document, Revision 3, dated February 1999, which was referenced in that AD as the appropriate source document necessary to accomplish the requirements of that AD.We have revised that AD to include that information by adding a new paragraph (e) to this revised AD. \n\nExplanation of Requirements of Rule \n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, this AD revises AD 2000-23-04 to continue to require revising the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to incorporate life limits for certain items and inspections to detect fatigue cracking in certain structures. This AD also adds information, as discussed above, pertaining to certain material incorporated by reference. \n\nDetermination of Rule's Effective Date \n\tThe FAA has determined that this AD action has no adverse economic impact on any person, does not impose any new requirements or provide any additional burden on any person, in order to accomplish the requirements of this AD. Therefore, prior notice and public procedures hereon are unnecessary and this amendment will be made effective as of December 19, 2000, the effective date of AD 2000-23-04. \n\nComments Invited \n\tAlthough this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. Submit comments using the following format: \n\nOrganize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues. \n\nFor each issue, state what specific change to the AD is being requested. \n\nInclude justification (e.g., reasons or data) for each request. \n\n\tComments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statementis made: "Comments to Docket Number 2001-NM-66-AD." The postcard will be date stamped and returned to the commenter. \n\nRegulatory Impact \n\tThe regulations adopted herein will not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. \n\n\tThe FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." \n\nList of Subjects in 14 CFR Part 39 \n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39 - AIRWORTHINESS DIRECTIVES \n\t1. The authority citation for part 39 continues to read as follows: \nAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\t2. Section 39.13 is amended by removing amendment 39-11974 (65 FR 68076, November 14, 2000), and by adding a new airworthiness directive (AD), amendment 39-12174, to read as follows: