Discussion \n\n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain The Boeing Company Model 767-200, -300, and -400ER series airplanes. The NPRM published in the Federal Register on January 4, 2016 (81 FR 24) (''the NPRM''). The NPRM was prompted by multiple reports of uncommanded escape slide inflation. The NPRM proposed to require modifying the escape slide regulator valves of the forward-entry door, forward-service door, aft- entry door, and aft-service door, and as applicable, modifying the escape slide regulator valves of the mid-entry door and mid-service door. We are issuing this AD to prevent out-of-tolerance trigger mechanism components (sector and sear) in the escape slide regulator valves, which can produce insufficient trigger engagement and reduced pull force values, possibly leading to uncommanded deployment of the slide during normal airplane maintenance or operation. Thiscondition could result in injury to passengers and crew, damage to equipment, and the slide becoming unusable in an emergency evacuation. \n\nComments \n\n\n\tWe gave the public the opportunity to participate in developing this AD. The following presents the comments received on the NPRM and the FAA's response to each comment. Air Astana, Air Line Pilots Association International (ALPA), and United Airlines supported the NPRM. \n\nRequest To Clarify Reference to the Escape Slide Regulator Valve \n\n\n\tAmerican Airlines (AAL) and Boeing requested that we clarify that the NPRM is applicable to the regulator valve associated with the escape slide assembly and not the slide door. The commenters pointed out that without clarification, the regulator valve could be misconstrued to be associated with the door system pressure cylinder assembly or the emergency power assist system (EPAS). \n\tWe agree to clarify the references to the escape slide regulator valve. We have revised the preamble in this final rule and paragraphs (e) and (g) of this AD to refer to the escape slide regulator valve. \n\nRequest To Revise Paragraph (g) of the Proposed AD \n\n\n\tAir New Zealand (ANZ) requested that we revise paragraph (g) of the proposed AD or add an additional paragraph to clarify that operators are required only to modify escape slide regulator valves that have not been previously modified as specified in UTC Aerospace Systems Service Bulletin 130104-25-432 or 4A3939-25-434. ANZ stated that paragraph (g) of the proposed AD would require all escape slide regulator valves on affected airplanes to be removed and modified as specified in Boeing Special Attention Service Bulletin 767-25-0548, Revision 1, dated April 23, 2015. ANZ also pointed out that if before or during the accomplishment of the actions specified in Boeing Special Attention Service Bulletin 767-25-0548, Revision 1, dated April 23, 2015, a determination could be made (by reviewing records or checking the part markings on the girt bar) that some of the escape slide regulator valves are already modified, as specified in UTC Aerospace Systems Service Bulletin 130104-25-432; or Service Bulletin 4A3939-25-434, then no additional work should be required on the modified escape slide regulator valves. \n\tWe agree that escape slide regulator valves that have already been modified do not need to be removed and modified again. Boeing Service Bulletin 767-25-0548, dated November 5, 2014, included in paragraph (h) of this AD, references UTC Aerospace Systems Service Bulletin 130104- 25-432; and Service Bulletin 4A3939-25-434 for the modification. As allowed by the phrase, ''unless already done,'' in paragraph (f) of this AD, if the requirements of this \n\n((Page 62000)) \n\nAD have already been accomplished, this AD does not require that those actions be repeated. Therefore, paragraph (g) this AD has not been changed in this regard. \n\nRequest To Reduce the Proposed Compliance Time \n\n\n\tALPA indicated its full support for the intent of the NPRM, but requested that we reduce the proposed 42-month compliance time for the modification of the escape slide regulator valves. ALPA pointed out that the risk of an uncommanded deployment is high and believes that the compliance time should be reduced in the interest of safety. ALPA provided no specific new compliance time. \n\tWe disagree with the request to reduce the 42-month compliance time. In developing an appropriate compliance time, we considered the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of modification of the escape slide regulator valves. Further, we arrived at the proposed compliance time with operator and manufacturer concurrence. Additionally, ALPA did not provide any additional data to support a shorter compliance time. In consideration of all of these factors, we determined that the compliance time, as proposed, represents an appropriate interval in which the escape slide regulator valves can be modified in a timely manner within the fleet, while still maintaining an adequate level of safety. Most ADs, including this one, permit operators to accomplish the requirements of an AD at a time earlier than the specified compliance time; therefore, an operator may choose to modify the escape slide regulator valves before the 42-month compliance time. If additional data are presented that would justify a shorter compliance time, we may consider further rulemaking on this issue. We have not changed this AD in this regard. \n\nRequest To Revise References in Certain Service Information \n\n\n\tAAL requested that we revise references included in UTC Aerospace Systems Service Bulletin 130104-25-432, dated August 11, 2014. AAL stated that UTC Aerospace Systems Service Bulletin 130104-25-432, dated August 11, 2014, contains internal references to the UTC Aerospace Systems Component Maintenance Manual (CMM) that are incorrect and reference an old revision of the UTC Aerospace Systems CMM with different paragraph references. \n\tWe agree that the references included in UTC Aerospace Systems Service Bulletin 130104-25-432, dated August 11, 2014, are incorrect. Since the specific references included in UTC Aerospace Systems Service Bulletin 130104-25-432, dated August 11, 2014, are not required for compliance with this AD, we have not changed the AD in this regard; however, we have identified this discrepancy to Boeing and UTC Aerospace Systems. \n\nEffect of Winglets on Accomplishment of the Proposed Actions \n\n\n\tAviation Partners Boeing stated that the installation of winglets per STC ST01920SE does not affect the accomplishment of the manufacturer's service instructions. \n\tWe agree with the commenter that STC ST01920SE does not affect the accomplishment of the manufacturer's service instructions. Therefore, the installation of STC ST01920SE does not affect the ability to accomplish the actions required by this AD. We have not changed this AD in this regard. \n\nConclusion \n\n\n\tWe reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this AD with the changes described previously and minor editorial changes. We have determined that these minor changes: \n\tAre consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM. \n\tWe also determined that these changes will not increase the economic burden on any operator or increase the scope of this AD. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tWe reviewed Boeing Special Attention Service Bulletin 767-25-0548, Revision 1, dated April 23, 2015. The service information describes procedures for modifying the escape slide regulator valves of the forward-entry door, forward-service door, aft-entry door, aft-service door, mid-entry door, and mid-service door. The modificationincludes replacing the existing trigger mechanism sector and sear of the escape slide regulator valve with new trigger mechanism sector and sear. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 302 airplanes of U.S. registry. \n\tWe estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per Cost on U.S. \n\tAction Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Replacement of trigger mechanism 15 work-hours x $85 per $2,236 $3,511 $1,060,322 \n\tcomponents--forward and aft-entry/ hour = $1,275. \n\tservice doors. Replacement of trigger mechanism 8 work-hours x $85 per 1,118 1,798 542,996 \n\tcomponents--mid(dash)entry/ hour = $680. \n\tmid(dash)service doors. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tAuthority for \n\tThis \n\tR \n\tu \n\tl \n\te \n\tm \n\ta \n\tk \n\ti \n\tn \n\tg \n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority. \n\tWe are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: ''General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\n((Page 62001)) \n\nRegulatory Findings \n\n\n\tThis AD will not have federalism implications under Executive Order 13132. This AD 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. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a ''significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), \n\t(3) Will not affect intrastate aviation in Alaska, and \n\t(4) Will not have a significant economic impact, positive ornegative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.