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 certain Boeing Model 767 series airplanes was published in the Federal Register on August 30, 1994 (59 FR 44672). That action proposed to require replacement of the currently installed door opening actuators of the emergency off-wing escape system on Model 767 series airplanes with new, improved actuators. \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\nResponse to Comments \n\n\tOne commenter supports the proposed rule. \n\n\tOne commenter requests that the name and address for obtaining service information from OEA Aerospace, Inc., be corrected. The FAA concurs. Since the issuance of the proposal, OEA has changed its name from OEA, Inc., to OEA Aerospace, Inc., and has relocated from Colorado to California. Therefore, the ADDRESSES section and paragraph (g) of the final rule have been revised accordingly. \n\n\tOne commenter requests that all references in the proposal to the escape system for Model 747 series airplanes be revised to "the door opening thrusters of the two-piece off-wing escape ramp and slide system." The commenter notes that this change in nomenclature would clearly differentiate the escape system installed on Model 747 series airplanes from those installed on Model 767 series airplanes. The FAA does not concur. Since this rule is applicable only to Model 767 series airplanes, the FAA finds that the broad, generic references to the escape systems cannot and has not created confusion for the operators. Therefore, no change to the final rule is necessary. \n\n\tOne commenter requests that the description of the unsafe condition be edited to specify that the unsafe condition would exist during certain flight configurations or during certain failure modes. The commenter states that the description should include the fact that only one door opening/snubbing actuator is necessary to open the door when the airplane is at a level attitude, and that two door opening/snubbing actuators are necessary to open the slide compartment door on the upward facing side when the airplane is at an adverse roll. The FAA does not concur that a revision to the description is necessary. According to section 39.1 ("Airworthiness Directives") of the Federal Aviation Regulations (14 CFR 39.1), the issuance of an AD is based on the finding that an unsafe condition exists or is likely to develop in aircraft of a particular type design. While the FAA's intent is to describe as specifically as possible the addressed unsafe condition that has prompted an AD, the FAA considers that it would be virtually impossible to list every potential flight configuration or failure mode for when the unsafe condition may exist or occur. To do so would add little value, and would make for an especially long, complex, and cumbersome regulation. \n\n\tTwo commenters request that the proposed compliance time of 2 years to accomplish the replacement of door opening actuators with new, improved actuators be extended to 4 years. One of the commenters asserts that safety of the fleet would be ensured in the interim with the repetitive inspections (weighing program) currently required by AD 92-16-17, amendment 39-8327 (57 FR 47987, October 21, 1992), which are restated in proposed paragraph (a). The other commenter notes that the suggested 4-year compliance time would allow operators to amortize these costs over a longer period of time, which would significantly minimize the economic impact of having to purchase and install the new actuators. Two other commenters point to a potential parts availability problem due to the large number of airplanes that will be affected by the proposed rule. \n\n\tThe FAA does not concur with these commenters' request. In developing an appropriate compliance time for this action, the FAA considered not only the degree of urgency associated with addressing the subject unsafe condition, but the manufacturer's recommendation as to an appropriate compliance time, the availability of required parts, and the practical aspect of replacing the actuators within a maximum interval of time allowable for all affected airplanes to continue to operate without compromising safety. The FAA has been advised that replacement actuators are readily available; therefore, obtaining them within the proposed compliance time should not pose a problem for any affected operator. Further, the FAA took into account the 2-year compliance time recommended by the manufacturer, as well as the number of days required for the rulemaking process; in consideration of these factors, the FAA finds that 2 years after the effective date of this final rule is consistent with the time recommended by the manufacturer. However, under the provisions ofparagraph (e) of the final rule, the FAA may approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. \n\n\tTwo commenters request that the proposed requirement of paragraph (c) to replace the actuators be optional rather than mandatory. These commenters state that safety of the fleet could be ensured in the interim with the repetitive inspections required by paragraph (a) of the proposal. The FAA does not concur. Paragraph (a) merely restates the requirements of AD 92-16-17, which proved to be unreliable in accurately determining the fluid level in the actuators. Therefore, the FAA has determined that these fluid-filled actuators must be replaced with new, improved actuators that are gas-filled. \n\n\tOne commenter requests that proposed paragraph (d) be revised to correct a typographical error in the reference to the Boeing part number. (The OEA part number was correctly referenced in the proposal. The Boeing part number was provided only for purposes of cross-referencing the OEA part number. It is only this cross-referenced Boeing part number that contained a typographical error.) The FAA concurs. Paragraph (d) of the final rule has been revised accordingly to correct this typographical error. \n\n\tOne commenter requests that the reference to airplanes in proposed paragraph (d) be revised to specify that the old oil-filled actuators may not be installed on Model 767 series airplanes equipped with off-wing emergency escape systems. The FAA does not concur. Since the rule is applicable to Boeing Model 767 series airplanes equipped with off-wing escape slides, the reference to airplanes clearly refers to Boeing Model 767 series airplanes equipped with off-wing escape slides. Repeating the applicability statement for this paragraph of the final rule would only be redundant and would not add to the clarity of the rule. Conversely, repeating the applicability for this paragraph may introduce confusion by leading the reader to deduce that the remaining paragraphs are applicable to other models or configurations. \n\n\tTwo commenters request that the cost of the proposed replacement action be partially borne by Boeing and partially by OEA. These commenters point to the faulty design of the OEA actuators that caused the initial problem (oil leakage from the actuators). Therefore, these commenters contend that OEA should assume partial financial responsibility for its faulty design, and that Boeing should assume partial financial responsibility for this problem since it chose to use these actuators on its airplanes. \n\n\tThe FAA cannot concur with this request. According to section 39.1 of the Federal Aviation Regulations (14 CFR 39.1), the issuance of an AD is based on the finding that an unsafe condition exists or is likely to develop in aircraft of a particular type design. The FAA has the authority to issue an AD when it is found that an unsafe condition is likely to exist or develop on other products of the same type design. In accordance with section 39.3 (14 CFR 39.3), operators whose products are subject to an AD must operate those products in accordance with the requirements of that AD. While the subject of this AD relates to a problem with the escape slides, this AD eliminates the unsafe condition by requiring replacement of the door opening actuators with new, improved actuators. The AD is the appropriate vehicle for mandating such actions. The FAA's authority in part 39 does not extend to whether or how those costs are negotiated. However, operators may negotiate the costs associated with accomplishing those actions with manufacturer.\n\n Other Changes to the Final Rule \n\n\tThe FAA has recently reviewed the figures it has used over the past several years in calculating the economic impact of AD activity. In order to account for various inflationary costs in the airline industry, the FAA has determined that it is necessary to increase the labor rate used in these calculations from $55 per work hour to $60 per work hour. The economic impact information, below, has been revised to reflect this increase in the specified hourly labor rate. \n\n\tAs a result of recent communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. The FAA points out that all airplanes identified in the applicability provision of an AD are legally subject to the AD. If an airplane has been altered or repaired in the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been added to this final rule to clarify this long-standing requirement. \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. Economic Impact There are approximately 460 Model 767 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 173 airplanes of U.S. registry will be affected by this AD. \n\n\tThe inspections and modification currently required by AD 92-16-17, and retained in this AD, take approximately 12 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $510 per airplane. Based on these figures, the total cost impact of the AD on U.S. operators is estimatedto be $212,790, or $1,230 per airplane. \n\n\tThe replacement will take approximately 2 work hours per airplane at an average labor rate of $60 per work hour. Required parts will cost approximately $6,400 per airplane. Based on these figures, the total cost impact of the replacement on U.S. operators is estimated to be $1,127,960, or $6,520 per airplane. \n\n\tThe total 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\n\tA full cost-benefit analysis has not been accomplished for this proposed AD. As a matter of law, in order to be airworthy, an aircraft must conform to its type design and be in a condition for safe operation. The type design is approved only after the FAA makes a determination that it complies with all applicable airworthiness requirements. In adopting and maintaining those requirements, the FAA has already made the determination that they establish a level of safety that is cost-beneficial. When the FAA, as in this AD action, makes a finding of an unsafe condition, this means that this cost-beneficial level of safety is no longer being achieved and that the required actions are necessary to restore that level of safety. Because this level of safety has already been determined to be cost-beneficial, a full cost-benefit analysis for this AD action would be redundant and unnecessary.\n\n Regulatory 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\n List of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption 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.\tThe authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. § 39.13 - (Amended) \n\n\t2.\tSection 39.13 is amended by adding the following new airworthiness directive: