Recently, the FAA received a report of failure of a cone bolt on the right side of the forward mount of an engine on a McDonnell Douglas Model DC-8-60 series airplane. Investigation revealed that corrosion pitting at the base of the bolt thread caused the cone bolt to fail. Further investigation indicated that this cone bolt, BAC II part number (P/N) DC- 8-21005-7, was re-manufactured from a 15-year old bolt. This bolt had accumulated 3,526 flight hours since it had been installed on the engine, which was modified by Burbank Aeronautical Corporation II (BAC II) in accordance with Supplemental Type Certificate (STC) SA4892NM. This condition, if not corrected in a timely manner, could result in failure of the cone bolt on the right side of the forward mount of the engine, which may lead to separation of the engine during a critical phase of flight. \n\n\tSince both STC's SA4892NM and SA5455NM specify the same cone bolts, the FAA has determined that the subject unsafe condition is likely to exist or develop on all Model DC-8-60 series airplanes equipped with engines modified by BAC II in accordance with either STC. The FAA finds that the differences in design and materials used to manufacture cone bolts having Barry Controls part number, P/N 96013-1, make them less susceptible to corrosion. Therefore, the FAA has determined that cone bolts having BAC II part number, DC-8-21005-7, must be replaced with cone bolts having the Barry Controls part number. \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent failure of the cone bolt on the right side of the forward mount of the engine, which may lead to separation of the engine during a critical phase of flight. This AD requires a one-time inspection to determine the part number of the cone bolt on the right side of the forward mount of the engine, and replacement of certain cone bolts having BAC II part numbers with cone bolts having Barry Controls part numbers. This AD also requires that operators submit a report to the FAA of the findings of discrepant bolts. \n\n\tThis is considered to be interim action until such time that all cone bolts having BAC II part numbers have been removed from the fleet and the FAA has accounted for all cone bolts having BAC II part numbers. The information from the required reports from operators will enable the FAA to account for those cone bolts and to determine if additional rulemaking action is warranted.\n\n\tSince a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. \n\nComments Invited \n\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. \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 Docketfor 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 statement is made: "Comments to Docket Number 95-NM-54-AD." The postcard will be date stamped and returned to the commenter. \n\n\tThe regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. \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\n\tAir transportation, Aircraft, Aviation safety, Safety.\n\n Adoption of the Amendment \n\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\n\t1.\tThe authority citation for part 39 continues to read as follows: \n\nAuthority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. \n\n§ 39.13 - (Amended) \n\n\t2.\tSection 39.13 is amended by adding the following new airworthiness directive: