2022-24-09: Air conditioning

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by: a. Removing Airworthiness (AD) 2021-14-20, Amendment 39-21647 (86 FR 38214, July 20, 2021); and b. Adding the following new AD: 2022-24-09 The Boeing Company: Amendment 39-22249; Docket No. FAA-2022-0588; Project Identifier AD-2022-00114-T. (a) Effective Date This airworthiness directive (AD) is effective January 26, 2023. (b) Affected ADs This AD replaces AD 2021-14-20, Amendment 39-21647 (86 FR 38214, July 20, 2021) (AD 2021-14-20). (c) Applicability This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, -500, -600, -700, -700C, -800, -900, and -900ER series airplanes, and Model 737-8, 737-9, and 737-8200 airplanes, certificated in any category. (d) Subject Air Transport Association (ATA) of America Code 21, Air conditioning. (e) Unsafe Condition This AD was prompted by reports of latent failures of the cabin altitude pressure switches, and the determination that using certain adapters while performing a functional test may lead to false failures of the cabin altitude pressure switches. The FAA is issuing this AD to address the unexpectedly high rate of latent failure of both pressure switches on the same airplane, which could result in the cabin altitude warning system not activating if the cabin altitude exceeds 10,000 feet, resulting in hypoxia of the flightcrew, and loss of control of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Repetitive Functional Tests (1) At the latest of the times specified in paragraphs (g)(1)(i) through (iii) of this AD, perform a functional test of the cabin altitude pressure switches having part number 214C50-2, using an adapter as specified in figure 1 to paragraph (g) of this AD, or an equivalent adapter, and matching hose to connect to the cabin altitude warning switch. Repeat the functional test thereafter at intervals not to exceed 2,000 flight hours. If, during any functional test, any cabin altitude pressure switch fails to activate at an altitude of between 9,000 and 11,000 feet, replace the switch before further flight. (i) Within 2,000 flight hours since the last functional test of the cabin altitude pressure switches. (ii) Prior to the accumulation of 2,000 total flight hours on the airplane. (iii) Within 90 days after the effective date of this AD. (2) Adapters are considered to be equivalent as long as the mating side with the switch meets the specifications in either paragraph (g)(2)(i) or (ii) of this AD: (i) Greater than or equal to 0.265 inch (0.673 cm) X 7/16-20-UNJF-3A and less than or equal to 0.438 inch (1.113 cm) X 7/16-20-UNJF-3A for the flareless end; or (ii) Less than or equal to 0.5 inch (1.27 cm) total with greater than or equal to 0.265 inch (0.673 cm) X 7/16-20-UNJF-3A thread for AN4 flared end. BILLING CODE 4610-13-P ER22DE22.004 ER22DE22.005 Note 1 to paragraph (g): Additional guidance for performing the functional test required by paragraph (g) of this AD can be found in Boeing 737-200 Aircraft Maintenance Manual (AMM) 21-33-11/501, Boeing 737-300/400/500/600/700/800/900/7/8/8200/9 AMM 21-33-00/501, 737CL AMM TASK CARD 31-026-01-01, 737CL AMM TASK CARD 31-010-01-01, 737NG AMM TASK CARD 31-020-00-01, and 737MAX AMM TASK CARD 31-020-00-01, and other approved maintenance procedures. (h) Minimum Equipment List (MEL) Provisions If any cabin altitude warning switch fails any functional test as required by this AD, the airplane may be operated as specified in the operator's existing FAA-approved MEL, provided provisions that specify operating the airplane at a flight altitude at or below 10,000 feet mean sea level (MSL) with the cabin altitude warning system inoperative are included in the operator's existing FAA-approved MEL. (i) Alternative Methods of Compliance (AMOCs) (1) The Manager, Seattle ACO Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or responsible Flight Standards Office, as appropriate. If sending information directly to the manager of the certification office, send it to the attention of the person identified in paragraph (j)(1) of this AD. Information may be emailed to [email protected]. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office. (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 Company Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO Branch, FAA, 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. (j) Related Information (1) For more information about this AD, contact Nicole Tsang, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3959; email: [email protected]. (2) For service information identified in this AD that is not incorporated by reference, 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; website myboeingfleet.com . (k) Material Incorporated by Reference None. Issued on December 2, 2022. Christina Underwood, Acting Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2022-27805 Filed 12-21-22; 8:45 am]BILLING CODE 4610-13-P