AD 2017-12-07

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-800, -900, and -900ER series airplanes. This AD was prompted by reports of in-flight failure of the left temperature control valve and control cabin trim air modulating valve. This AD requires replacing the left temperature control valve and control cabin trim air modulating valve. We are issuing this AD to address the unsafe condition on these products.

Final rule.

Adoption of the Amendment \n\n\n\tAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n0 1. The authority citation for part 39 continues to read as follows: \n\n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n\n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD): \n\n2017-12-07 The Boeing Company: Amendment 39-18922; Docket No. FAA- 2016-9432; Directorate Identifier 2016-NM-116-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective July 20, 2017. \n\n(b) Affected ADs \n\n\n\tNone. \n\n(c) Applicability \n\n\n\tThis AD applies to The Boeing Company Model 737-800, -900, and - 900ER series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 737-21A1203, dated June 8, 2016. \n\n(d) Subject \n\n\n\tAir Transport Association (ATA) of America Code 21, Air conditioning. \n\n(e) Unsafe Condition \n\n\n\tThis AD was prompted by reports of in-flight failure of the left temperature control valve and control cabin trim air modulating valve. We are issuing this AD to prevent temperatures in excess of 100 degrees Fahrenheit in the flight deck or the passenger cabin during cruise, which could lead to the impairment of the flight crew and prevent continued safe flight and landing. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Replacement of the Left Temperature Control Valve and Control Cabin Trim Air Modulating Valve \n\n\n\tWithin 60 months after the effective date of this AD, replace the left temperature control valve and control cabin trim air modulating valve, as applicable, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737- 21A1203, dated June 8, 2016. \n\n(h) Parts Installation Prohibition \n\n\n\tAs of the effective date of this AD, no person may install a temperature control valve, part number 398908-4, in either the left temperature control valve location or the control cabin trim air modulating valve location on any Model 737-800, -900, or -900ER airplane. \n\n(i) Alternative Methods of Compliance (AMOCs) \n\n\n\t(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 \n\n((Page 27419)) \n\nCFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in paragraph (j) of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov. \n\t(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. \n\t(3) An AMOC that provides an acceptable level of safety may be used for any repair, modification, or alteration required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD. \n\t(4) For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (i)(4)(i) and (i)(4)(ii) of this AD apply. \n\t(i) The steps labeled as RC, including substeps under an RC step and any figures identified in an RC step, must be done to comply with the AD. If a step or substep is labeled ''RC Exempt,'' then the RC requirement is removed from that step or substep. An AMOC is required for any deviations to RC steps, including substepsand identified figures. \n\t(ii) Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the RC steps, including substeps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. \n\n(j) Related Information \n\n\n\tFor more information about this AD, contact Stanley Chen, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle ACO, 1601 Lind Avenue SW., Renton, WA 98057- 3356; phone: 425-917-6585; fax: 425-917-6590; email: stanley.chen@faa.gov. \n\n(k) Material Incorporated by Reference \n\n\n\t(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise. \n\t(i) Boeing Alert Service Bulletin 737-21A1203, dated June 8, 2016. \n\t(ii) Reserved. \n\t(3) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740- 5600; telephone 562-797-1717; Internet https://www.myboeingfleet.com. \n\t(4) You may view this service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221. \n\t(5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

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 737-800, -900, and -900ER series airplanes. The NPRM published in the Federal Register on December 5, 2016 (81 FR 87494). The NPRM was prompted by reports of in-flight failure of the left temperature control valve and control cabin trim air modulating valve. The NPRM proposed to require replacing the left temperature control valve and control cabin trim air modulating valve. We are issuing this AD to prevent temperatures in excess of 100 degrees Fahrenheit in the flight deck or the passenger cabin during cruise, which could lead to the impairment of the flight crew and prevent continued safe flight and landing. \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.Support for the NPRM \n\n\n\tThe Air Line Pilots Association, International and United Airlines (UAL) stated that they support the NPRM. \n\nRequest To Clarify the Unsafe Condition \n\n\n\tBoeing requested that we change a sentence in the Discussion section of the NPRM from ''This condition, if not corrected, could result . . . .'' to ''This condition, if not corrected or mitigated by crew completion of the cabin temperature hot procedure under Section 2.8 of the quick reference handbook (QRH), could result. . . .'' Boeing stated that the cabin temperature hot procedure was created specifically to address failed open temperature control valves. They further stated that this procedure is an effective remedy for failed valves and enhances safety. \n\tWe disagree with the request to revise the description of the unsafe condition in the Discussion section. More than half of the affected fleets are operated by non-U.S. air carriers, who are not required to incorporate the revised Flight Crew Operations Manual (FCOM), which includes the QRH. Since this AD does not require incorporation of the FCOM, or the QRH, and instead requires replacement of two control valves, we do not find it appropriate to reference the QRH as a mitigating factor in the description of the unsafe condition. We have not changed this AD regarding this issue. \n\nRequest To Allow Maintenance Records Review To Determine Installed Parts \n\n\n\tAlaska Airlines (Alaska) asked that we revise paragraph (g) of the proposed AD, which mandates replacement of certain valves, to state that a records review is acceptable for compliance with the requirements of that paragraph (by determining which valves must be replaced). Alaska noted that a similar statement is included as a note in Boeing Alert Service Bulletin 737-21A1203, dated June 8, 2016, and that the note and steps 3.B.1.c. and 3.B.1.d. of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-21A1203, dated June 8, 2016, are not Required for Compliance (RC). (We note that those steps state that no further action is required for nondiscrepant parts.) Alaska indicated that because the NPRM does not include a similar statement, an airline doing only a records check, and finding no discrepant parts, could be considered non-compliant. \n\tWe agree with the commenter. Paragraph (g) of this AD requires replacing certain valves in accordance with the Accomplishment Instructions in Boeing Alert Service Bulletin 737-21A1203, dated June 8, 2016. We did not intend for operators to need an alternative method of compliance (AMOC) to address the situation described by the commenter. Therefore, we have revised paragraph (g) of this AD to add the phrase ''as applicable'' to the requirement for valve replacements so that operators will not need an AMOC if the correct valve is already installed. \n\nRequest To Correct the Manufacturer Information \n\n\n\tUAL stated that the header section of the NPRM referenced the wrong aircraft manufacturer, reading: ''Proposed Rule: Airworthiness Directives: Bombardier, Inc. Airplanes.'' UAL noted that it should say The Boeing Company Airplanes. \n\tWe acknowledge the commenter's concern. However, the NPRM correctly identifies the manufacturer as Boeing, as published in the Federal Register. It was the docket in the Federal Docket Management System (FDMS) that incorrectly identified the manufacturer as Bombardier. This information has been corrected. Therefore, we have not changed this final rule regarding this issue. \n\nEffect of Winglets on Accomplishment of the Proposed Actions \n\n\n\tAviation Partners Boeing stated that the installation of winglets per Supplemental Type Certificate (STC) \n\n((Page 27418)) \n\nST00830SE does not affect the accomplishment of the manufacturer's service instructions. \n\tWe agree with the commenter that STC ST00830SE does not affect the accomplishment of the manufacturer's service instructions. Therefore, the installation of STC ST00830SE 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 change 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 this change 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 Alert Service Bulletin 737-21A1203, dated June 8, 2016. The service information describes procedures for replacing the left temperature control valve and control cabin trim air modulating valve, part number 398908-4, with new part number 398908-3 or 398908-5. 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 319 airplanes of U.S. registry. We estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost on U.S. \n\tAction Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Replacement of valves.......... 9 work-hours x $85 per $4,800 $5,565 per valve.. $1,775,235 per \n\thour = $765 per valve. valve. ---------------------------------------------------------------------------------------------------------------- \n\nAuthority for This Rulemaking \n\n\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\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 or negative, 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.