# AD 2007-26-03: Main equipment center - Type: Airworthiness directive - Status: Current - Products: Boeing 747-200C Series and 747-200F Series - Effective: January 22, 2008 - Published: December 17, 2007, 72 FR 71218–71220 - Issued: December 10, 2007 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-15305 - Docket: FAA-2007-28924 (https://www.regulations.gov/docket/FAA-2007-28924) - Project: 2007-NM-051-AD - Registered aircraft: 3 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/b7/6c/b76c5369216ae3f14bfa22c0c2021c5f0524c0440d7ee49da77782c00d92af8d (from https://www.govinfo.gov/content/pkg/FR-2007-12-17/pdf/E7-24340.pdf) - Federal Register: https://www.federalregister.gov/documents/2007/12/17/E7-24340/airworthiness-directives-boeing-model-747-200c-and--200f-series-airplanes - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/093A34B971931DF3862573B4005765C4.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/2007-26-03 ## Summary The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-200C and -200F series airplanes. This AD requires, among other actions, installing mounting brackets, support angles, and moisture curtains in the main equipment center. This AD results from reports of water contamination in the electrical/electronic units in the main equipment center. We are issuing this AD to prevent water contamination of the electrical/electronic units, which could cause the electrical/electronic units to malfunction, and as a consequence, could adversely affect the airplane's continued safe flight. ## The airworthiness directive ### Adoption of the Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: 1. The authority citation for part 39 continues to read as follows: 2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD): 2007-26-03 Boeing: Amendment 39-15305. Docket No. FAA-2007-28924; Directorate Identifier 2007-NM-051-AD. ### (a) Effective Date (a) This AD becomes effective January 22, 2008. ### (b) Affected ADs (b) None. ### (c) Applicability (c) This AD applies to Boeing Model 747-200C and -200F series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-25A3430, dated February 15, 2007. ### (d) Unsafe Condition (d) This AD results from reports of water contamination in the electrical/electronic units in the main equipment center. We are issuing this AD to prevent water contamination of the electrical/electronic units, which could cause the electrical/electronic units to malfunction, and as a consequence, could adversely affect the airplane's continued safe flight. ### (e) Compliance (e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. ### (f) Installations (f) Within 24 months after the effective date of this AD, install mounting brackets, support angles, and moisture curtains in the main equipment center, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3430, dated February 15, 2007. ### (g) Prior or Concurrent Requirements (g) For airplanes identified as Group 1 and Group 3 airplanes in Boeing Alert Service Bulletin 747-25A3430, dated February 15, 2007: Prior to or concurrently with the requirements of paragraph (f) of this AD, install drip shields (including a drip pan assembly, drain tubing, and attaching hardware) over the forward, outboard halves of the E1-1 and E3-1 shelves in the main equipment bay, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-38A2073, Revision 3, dated May 22, 2003. (h) Installation of drip shields before the effective date of this AD in accordance with paragraph (a) and Note 2 of AD 2001-24-30, amendment 39-12547, is acceptable for compliance with the corresponding actions specified in paragraph (g) of this AD. ### (i) Alternative Methods of Compliance (AMOCs) (i)(1) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. (2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. ### (j) Material Incorporated by Reference (j) You must use the service bulletins identified in Table 1 of this AD to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 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. *Table 1.—Material Incorporated by Reference* | Service Bulletin | Revision level | Date | | --- | --- | --- | | Boeing Alert Service Bulletin 747-25A3430 | Original | February 15, 2007. | | Boeing Alert Service Bulletin 747-38A2073 | 3 | May 22, 2003. | ## Rule preamble ### Dates This AD becomes effective January 22, 2008. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of January 22, 2008. ### Addresses For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. ### For further information contact Marcia Smith, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6484; fax (425) 917-6590. ### Discussion The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Boeing Model 747-200C and -200F series airplanes. That NPRM was published in the Federal Register on August 16, 2007 (72 FR 45954). That NPRM proposed to require, among other actions, installing mounting brackets, support angles, and moisture curtains in the main equipment center. ### Comments We provided the public the opportunity to participate in the development of this AD. We have considered the comment received. ### Request To Refer to Earlier Revision of a Referenced Service Bulletin Boeing requests that paragraph (g) of the NPRM be revised to include Boeing Alert Service Bulletin 747-38A2073, Revision 1, dated June 21, 1990; and Revision 2, dated April 26, 2001; as additional sources of service information for accomplishing the prior or concurrent requirements. Boeing states that this will align the NPRM with Boeing Alert Service Bulletin 747-38A2073, Revision 3, dated May 22, 2003 (referred to in the NPRM as an appropriate source of service information for accomplishing the prior or concurrent requirements). We partially agree. We agree with Boeing that accomplishing the actions specified in Revisions 1 and 2 of Boeing Alert Service Bulletin 747-38A2073 is acceptable for compliance with the corresponding actions required by paragraph (g) of this AD. However, we do not agree that a change to the final rule is necessary. As mentioned in the Relevant Service Information section of the NPRM, AD 2001-24-30, amendment 39-12547 (66 FR 64104, December 12, 2001), requires installing drip shields in accordance with Boeing Alert Service Bulletin 747-38A-2073, Revision 2; or in accordance with Revision 1 or Original Release, dated November 30, 1989, if done before the effective date of that AD. In addition, paragraph (h) of this AD states, “Installation of drip shields before the effective date of this AD in accordance with paragraph (a) and Note 2 of AD 2001-24-30, amendment 39-12547, is acceptable for compliance with the corresponding actions in paragraph (g) of this AD.” We have made no change to the final rule in this regard. ### Conclusion We have carefully reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD as proposed. ### Interim Action This is considered to be interim action. The manufacturer has advised that it currently is developing another modification that will address the unsafe condition identified in this AD. Once this modification is developed, approved, and available, the FAA might consider additional rulemaking. ### Costs of Compliance There are about 79 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD. *Estimated Costs* | Action | Work hours | Average labor rate per hour | Parts | Cost per airplane | Number of U.S.-registered airplanes | Fleet cost | | --- | --- | --- | --- | --- | --- | --- | | Installation | 3 | $80 | $8,960 | $9,200 | 25 | $230,000 | | Prior or concurrent requirements of AD 2001-24-30 | 32 | 80 | 4,497 | 7,057 | 25 | 176,425 | ### Authority for This Rulemaking Title 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. We 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. ### Regulatory Findings We have determined that this 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. For the reasons discussed above, I certify that this AD: (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. We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A20WE](https://openairdocs.org/tcds/A20WE): The Boeing Company; names 2 of 14 models: 747-200F Series, 747-200C Series ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 3 (3 by airframe model, 0 by engine model) - Makers: Boeing 3 Models with the most aircraft: - [Boeing 747-251F](https://openairdocs.org/model/boeing-747-251f): 2 aircraft (airframe model) - [Boeing 747-273C](https://openairdocs.org/model/boeing-747-273c): 1 aircraft (airframe model) All 2 models: https://openairdocs.org/ad/2007-26-03/models.md Every aircraft: https://openairdocs.org/ad/2007-26-03/aircraft.md ## Related documents - [Proposed rule FAA-2007-28924](https://openairdocs.org/proposed/FAA-2007-28924): Notice of proposed rulemaking (NPRM), published Aug 16, 2007 Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.