A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to all Boeing Model 757-200PF series airplanes was published in the Federal Register on February 10, 1999 (64 FR 6577). That action proposed to require revising the Airplane Weight & Balance (W&B) Manual to prohibit operation of any airplane without side vertical restraints installed on the main cargo deck when carrying a particular pallet. That action also proposed to provide for optional terminating action for the Airplane W&B Manual revision. \n\nComments \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\nSupport for the Proposal \n\n\tOne commenter supports the proposed rule, and another states that it has no comment. \n\nRequest for Extension of the Compliance Time \n\n\tOne commenter requeststhat the compliance time for the actions required by this proposed AD be extended to at least 28 months after the airplane manufacturer provides a service bulletin to modify the airplanes to install side vertical restraints. The commenter states that, in 12 years of operating with Type II cargo pallets, it has never had an adverse incident. The commenter states that this proposed AD would have an enormous effect on its fleet because it will have to use Type I cargo pallets. The commenter states that Type I cargo pallets are not readily available and, because other operators with which the commenter interacts do not use Type I cargo pallets, it will be difficult to use the services of Model 757-200PF series airplanes. \n\n\tThe FAA concurs that the compliance time can be extended somewhat. The FAA does not intend for this AD to place undue hardship on the affected operators. Based on the information provided by the commenter, the FAA now recognizes that a compliance time of 28 months would better allow operators to purchase Type I cargo pallets or make the necessary modifications to airplanes to resume use of Type II cargo pallets. In addition, a compliance time of 28 months is identical to the compliance times for similar actions to correct similar identified unsafe conditions on other transport category cargo airplanes. Paragraph (a) of the final rule has been revised accordingly. \n\nRequest for Use of Modified Type II Cargo Pallets \n\n\tOne commenter requests that the proposed AD be revised to allow the use of modified Type II cargo pallets that meet the NAS3610 requirements. The commenter states that the problem with the Type II cargo pallets is that they are too flexible, but that the pallets could be manufactured with acceptable rigidity characteristics. \n\n\tThe FAA does not concur with the commenter's request. While the FAA accepts in principle that the Type II cargo pallets could be manufactured with acceptable rigidity characteristics, the commenter has not submitted any data or configuration definition that would allow their use. However, the commenter may request approval for an alternative method of compliance in accordance with the provisions of paragraph (c) of this AD. The request should include sufficient information for the FAA to evaluate the proposal. No change to the rule is necessary. \n\nRequest for Use of a Tether Assembly \n\n\tOne commenter requests that the proposed AD be revised to allow the use of a tether assembly. The commenter states that a tether assembly is a device that restricts the shifting of Type II cargo pallets such that the cargo shift will not affect the airplane's center of gravity. The commenter states that such an assembly appears to be an economical method to allow continued operation of the Model 757-200PF series airplane with Type II cargo pallets. However, another commenter states that it has evaluated such a system and concludes that, if used improperly, it could result in considerable damage to aircraft structure and cargo handling system components. \n\n\tThe FAA does not concur with the first commenter's request to allow the use of a tether assembly. While the FAA accepts in principle that a tether assembly should adequately address the identified unsafe condition, the FAA has concluded that it would be prudent to defer a decision until further information becomes available. The 28-month compliance time should allow sufficient time to resolve the issues raised by the second commenter prior to implementation of the W&B Manual revision. Assuming satisfactory resolution, the first commenter may request approval for an alternative method of compliance in accordance with the provisions of paragraph (c) of this AD. No change to the rule is necessary. \n\nExplanation of Changes Made to Proposal \n\n\tThe FAA has revised paragraph (c) of the final rule to include instructions to submit requests of approval for an alternative method of compliance through an appropriate Principal Maintenance Inspector. The proposed rule only contained instructions to submit requests through an appropriate Principal Operations Inspector. Operators should submit requests for approval for an alternative method of compliance for paragraph (a) of this AD through their Principal Operations Inspector, whereas requests for approval for an alternative method of compliance for paragraph (b) of this AD should be submitted through their Principal Maintenance Inspector. \n\nConclusion \n\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 100 airplanes of the affected design in the worldwide fleet. The FAA estimates that 90 airplanes ofU.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required Airplane W&B Manual revision, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $5,400, or $60 per airplane. \n\n\tThe cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. \n\nRegulatory Impact \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\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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\n PART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: