A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 92-16-17, Amendment 39-8327 (57 FR 47987, October 21, 1992), which is applicable to certain Boeing Model 747 and 767 series airplanes, was published in the Federal Register on June 26, 1996 (61 FR 33050). The action proposed to continue to require repetitive inspections of the door opening thrusters and door opening/snubbing actuators for proper oil quantity, and modification of the off-wing compartment latching assemblies for Model 747 series airplanes. For those airplanes, the action proposed to add a requirement for replacement of existing door opening thrusters with new, improved thrusters. Additionally, the action proposed to remove Model 767 series airplanes from the applicability of AD 92-16-17, since those airplanes are addressed currently by AD 95-08-11, Amendment 39-9200 (60 FR 20013).\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\tTwo commenters support the proposed rule.\n\n Request to Revise Description of Effect of Required Actions \n\n\tOne commenter requests that Summary section of the preamble to the proposal be revised to replace the word "preclude" with the work "detect" in the following sentence that appeared in that section: "This proposal is prompted by reports indicating that the requirements of the existing AD do not adequately preclude leakage of fluid from the actuators." The commenter indicates that the actions required by AD 95-08-11 do not "preclude" fluid leakage; rather, they provide a means of detecting decreased fluid quantities in an effort to prevent failure of the escape slide to deploy.\n\n\tThe FAA concurs with the commenter's request and justification, and has revised the Summary section of this final rule accordingly. \n\nRequest to Explain Removalof Certain Airplanes from Applicability \n\n\tThe same commenter requests that the Summary section of the preamble to the proposal be revised to specify that the new AD action would remove Model 767 series airplanes from the applicability of AD 92-16-17, since those airplanes are addressed currently by AD 95-08-11. The commenter notes that the existing AD is, in effect, being superseded by two AD's, one for each airplane model. The clarification will direct operators of Model 767 series airplanes to the appropriate AD. \n\n\tThe FAA does not consider that additional clarification is necessary. This issue was discussed in detail elsewhere in the preamble to the proposal. Such detail is unnecessary in the Summary section to a rule, since that section is intended to provide only a synopsis of the proposed or required actions. Further, since operators of Model 767 airplanes are no longer subject to this AD, there is no reason to address those operators further in this final rule. \n\nRequest to Remove Paragraph (d) from the Proposal \n\n\tThe Air Transport Association (ATA) of America, on behalf of one of its members, requests that the FAA remove paragraph (d) from the proposal, which would require that all spare parts be modified as of the effective date of the final rule. The ATA states that inclusion of that paragraph would place an unnecessary burden on operators of Model 747 series airplanes. The commenter points out that AD 95-08-11 provides operators of Model 767 series airplanes an interval of two years to modify uninstalled actuators. The ATA maintains that there is no need to create different compliance periods between installed and uninstalled components, except where results of a risk assessment support two compliance periods. The commenter concludes that proposed paragraph (d) is unnecessary since paragraph (c) requires that all airworthy units, installed and uninstalled, be modified within two years. \n\n\tThe FAA concurs partially. First, the FAA does not agree that paragraph (d) should be removed from this final rule altogether. The FAA finds that paragraph (d) must be included in the AD to ensure that only new, improved door opening thrusters (that are not fluid filled) are installed on the affected airplanes. However, upon reconsideration of the compliance time proposed in that paragraph, the FAA finds that it is appropriate to revise the compliance time for paragraph (d) of this final rule so that is parallel to a similar paragraph in AD 95-08-11, which addresses these same components for Model 767 series airplanes. Accordingly, paragraph (d) of this final rule has been revised to specify that only new, improved door opening thrusters shall be installed on the affected airplanes as of two years after the effective date of this AD. This revision will also preclude the potential for any parts availability problem that may arise in the interim.\n\n\tSecond, the FAA must clarify for this commenter that neither paragraph (c) nor paragraph (d) of this AD address "uninstalled" components. Part 39 of the Federal Aviation Regulations (14 CFR part 39) precludes AD actions taken to address components that are not currently installed on the airplane (or product). Therefore, the FAA cannot require via an AD that operators inspect, repair, or modify a "spare part" (i.e., currently in an operator's parts inventory). However, the FAA can ensure, via a requirement such as that specified in paragraph (d) of this AD, that any spare part is inspected, repaired, or modified prior to it being installed on an airplane. Accordingly, paragraphs (c) and (d) of this AD do not require that any action to be taken on "uninstalled" parts (spares). The requirements of those paragraphs only specify that, whenever a door opening thruster is to be installed on an airplane now or in the future, that thruster must be an improved model. \n\nRequest to Reference Additional Service Information \n\n\tOne commenter requests that the proposal be revised to cite the following service bulletin revisions, which have been reviewed and approved by the FAA, as additional sources of appropriate service information: \n\n\t Boeing Service Bulletin 747-25-3073, Revision 1, dated August 1, 1996. \n\t Boeing Service Bulletin 747-25-2951, Revision 1, dated May 13, 1993.\n\t Boeing Service Bulletin 747-25-2951, Revision 2, dated September 30, 1993. \n\t OEA Service Bulletin 2174200-25-013, Revision 1, dated September 14, 1993. \n\t OEA Service Bulletin 2174200-25-013, Revision 2, dated November 1, 1993. \n\t OEA Service Bulletin 2174200-25-013, Revision 3, dated January 13, 1994. \n\n\tThe FAA agrees that the service bulletins listed above, with the exception of Boeing Service Bulletin 747-25-3073, Revision 1, dated August 1, 1996, should be referenced in the final rule. The FAA has confirmed that Boeing has not yet released Revision 1 of Service Bulletin 747-25-3073 due to changes in the engineering aspects prior to receipt ofFAA approval of that service bulletin. However, Boeing advises that it plans to issue Revision 1 of that service bulletin in early 1997 and, subsequently, will request approval of it as an alternative method of compliance with this AD. \n\n\tThe FAA has revised the final rule to add new NOTES 2 and 3, which specify that accomplishment of the actions required by this AD in accordance with the last five service bulletins listed above is acceptable for compliance with the requirements of this AD. \n\nRequest to Add Address to Obtain Service Information \n\n\tOne commenter requests that the FAA revise the Addresses section of the preamble to the proposal to include the address for OEA Aerospace Inc., since an OEA service bulletin is cited in the proposal. \n\n\tThe FAA concurs. The address for OEA was omitted inadvertently from the proposal, but has been included in this final rule. \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\n Cost Impact \n\n\tThere are approximately 400 Model 747 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 125 airplanes of U.S. registry will be affected by this proposed AD. \n\n\tThe actions that are currently required by AD 92-16-17 and retained in this new AD take approximately 12 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts cost approximately $510 per airplane. Based on these figures, the cost impact on U.S. operators of the actions currently required is estimated to be $153,750, or $1,230 per airplane.\n \n\tThe new actions that are required by this new AD will take approximately 2 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $6,400 per airplane. Based on these figures, the cost impact on U.S. operators of the new requirements of this AD is estimated to be $815,000, or $6,520 per airplane. \n\n\tThe cost impact figures discussed above are 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, 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\nPART 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\n\t2. Section 39.13 is amended by removing Amendment 39-8327 (57 FR 47987, October 21, 1992), and by adding a new airworthiness directive (AD), Amendment 39-9924, to read as follows: