# AD 99-24-16: Cable Guards in Lateral Control System - Type: Airworthiness directive - Status: Current - Products: Boeing 747-100 Series, 747-100B Series, 747-100B SUD Series, 747-200B Series, 747-200C Series, 747-200F Series, 747-300 Series, 747-400 Series, 747-400D Series, 747-400F Series, 747SP Series and 747SR Series - Effective: January 4, 2000 - Published: November 30, 1999, 64 FR 66752–66754 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-11441 - Docket: 99-NM-46-AD - Registered aircraft: 63 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/cf/eb/cfebaeb8dbb2151525e18d7c40ce2b850e43560724eed47b468bfd0ceebb82f4 (from https://www.govinfo.gov/content/pkg/FR-1999-11-30/pdf/99-30629.pdf) - Federal Register: https://www.federalregister.gov/documents/1999/11/30/99-30629/airworthiness-directives-boeing-model-747-series-airplanes - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/720AEA5A2B14C39386256988004A461E.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/99-24-16 ## Summary This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that requires removal of cable guards in the lateral control system and replacement with new, improved cable guards. This amendment is prompted by reports of high control wheel forces and restricted control wheel movement. The actions specified by this AD are intended to prevent deterioration of cable guards in the lateral control system, which could result in a jam of the lateral control system and consequent reduced lateral controllability of the airplane. ## The airworthiness directive 99-24-16 BOEING: Amendment 39-11441. Docket 99-NM-46-AD. Applicability: Model 747 series airplanes, as listed in Boeing Alert Service Bulletin 747-27A2364, dated September 3, 1998, certificated in any category. NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance: Required as indicated, unless accomplished previously. To prevent deterioration of cable guards in the lateral control system, which could result in a jam of the lateral control system and consequent reduced lateral controllability of the airplane, accomplish the following: Replacement (a) Within 2 years after the effective date of this AD, remove existing cable guards in the lateral control system and replace with new, improved cable guards in accordance with Boeing Alert Service Bulletin 747-27A2364, dated September 3, 1998. NOTE 2: Removal of existing cable guards and replacement with new, improved cable guards between Stations 300 and 420 accomplished prior to the effective date of this AD in accordance with Boeing Service Letter 747-SL-27-134, dated December 23, 1993, is considered acceptable for compliance with paragraph (a) of this AD. Spares (b) As of the effective date of this AD, no person shall install a cable guard with a part number and dash number listed in Table1 of this AD, on any airplane. TABLE 1 Cable Guards Not To Be Installed Part Number Part Dash Number 65B82025 65B82025-2 through 65B82025-4 inclusive 65B82025-9 through 65B82025-10 inclusive 65B82025-17 through 65B82025-22 inclusive 65B82025-25 65B82025-27 through 65B82025-46 inclusive 65B82025-48 through 65B82025-57 inclusive 65B82204 65B82204-9 through 65B82204-10 inclusive 65B82204-18 through 65B82204-22 inclusive 65B82204-25 65B82204-31 through 65B82204-40 inclusive 65B82204-43 through 65B82204-44 inclusive 65B82204-61 through 65B82204-76 inclusive 65B82204-81 through 65B82204-86 inclusive 65B82443 65B82443-9 through 65B82443-10 inclusive 65B82443-12 65B82443-14 through 65B82443-18 inclusive 65B82443-21 through 65B82443-22 inclusive 65B82443-26 through 65B82443-31 inclusive Alternative Methods of Compliance (c) An alternative method of compliance or adjustment of the compliance time thatprovides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. Special Flight Permits (d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. Incorporation by Reference (e) The replacement shall be done in accordance with Boeing Alert Service Bulletin 747-27A2364, dated September 3, 1998. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (f) This amendment becomes effective on January 4, 2000. ## Rule preamble ### Supplementary information A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes was published in the Federal Register on July 16, 1999 (64 FR 38383). That action proposed to require removal of cable guards in the lateral control system and replacement with new, improved cable guards. Comments Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. Support for the Proposal One commenter supports the proposed rule. Request to Revise Cost Impact Information One commenter requests that the cost impact information be revised to include the work hours required to gain access and close up, and to test the lateral flight control system after the replacement of the cable guards. The commenter states that cost impact informationprovided in the proposed rule estimates 10 work hours per airplane is necessary for the replacement, whereas the Boeing service bulletin estimates 31.5 work hours per airplane. The FAA does not concur with the commenter's request. The cost impact information, below, describes only the "direct" costs of the specific actions required by this AD. The number of work hours necessary to accomplish the required actions, specified as 10 in the cost impact information, below, was provided to the FAA by the manufacturer based on the best data available to date. This number represents the time necessary to perform only the actions actually required by this AD. The FAA recognizes that, in accomplishing the requirements of any AD, operators may incur "incidental" costs in addition to the "direct" costs. The cost analysis in AD rulemaking actions, however, typically does not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. Because incidental costs may vary significantly from operator to operator, they are almost impossible to calculate. No change to the final rule is necessary in this regard. Request to Extend the Compliance Time One commenter requests that the compliance time for the replacement of the cable guards be extended from 2 years to 4 years. The commenter states that it has replaced deteriorated cable guards found during various inspection and maintenance tasks in the area, but that it is unaware of any cases where deterioration of the cable guards has led to binding of the control cables. Due to the access required for the replacement, the commenter states that a longer compliance time would better accommodate its work schedule. The FAA does not concur with the commenter's request to extend the compliance time. In developing an appropriate compliance time for this action, the FAA considered the safety implications, parts availability, andnormal maintenance schedules for timely accomplishment of the modification. In consideration of these items, as well as two reports of cable binding due to cable guard deterioration in service, the FAA has determined that 2 years represents an appropriate interval of time allowable wherein the modifications can be accomplished during scheduled maintenance intervals for the majority of affected operators, and an acceptable level of safety can be maintained. No change to the final rule is necessary in this regard. Request to Consider Repetitive Inspections in Lieu of Replacement One commenter requests that the FAA consider allowing repetitive inspections of the cable guards in lieu of the required replacement. The commenter states that repetitive inspections and on-condition replacement of cable guards, as well as the elimination of existing cable guards from spares, provides an acceptable level of safety. The commenter also notes that, on freighters, the lateral control cables are exposed and can be easily inspected. The FAA does not concur with the commenter's request. The FAA has determined that the eventual replacement of all existing cable guards is required because it is not known how long the cable guards will remain intact after exposure to airplane grease. No change to the final rule is necessary in this regard. Conclusion After 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 as proposed. Cost Impact There are approximately 956 Model 747 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 219 airplanes of U.S. registry will be affected by this AD, that it will take approximately 10 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $11,000 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $2,540,400, or $11,600 per airplane. The cost impact figure discussed above is 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. Regulatory Impact The 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. For 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." List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment Accordingly, 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: PART 39 - AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 (Amended) 2. Section 39.13is amended by adding the following new airworthiness directive: ## 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 12 of 14 models: 747-100B Series, 747SP Series, 747-400D Series, 747-400F Series, 747-200B Series, 747-200F Series, 747-300 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: 63 (63 by airframe model, 0 by engine model) - Makers: Boeing 63 Models with the most aircraft: - [Boeing 747-446](https://openairdocs.org/model/boeing-747-446): 10 aircraft (airframe model) - [Boeing 747-422](https://openairdocs.org/model/boeing-747-422): 8 aircraft (airframe model) - [Boeing 747-412](https://openairdocs.org/model/boeing-747-412): 5 aircraft (airframe model) - [Boeing 747-400F](https://openairdocs.org/model/boeing-747-400f): 4 aircraft (airframe model) - [Boeing 747-409](https://openairdocs.org/model/boeing-747-409): 4 aircraft (airframe model) - [Boeing 747-481F](https://openairdocs.org/model/boeing-747-481f): 3 aircraft (airframe model) - [Boeing 747-409F](https://openairdocs.org/model/boeing-747-409f): 3 aircraft (airframe model) - [Boeing 747-481](https://openairdocs.org/model/boeing-747-481): 3 aircraft (airframe model) - [Boeing 747-428F](https://openairdocs.org/model/boeing-747-428f): 3 aircraft (airframe model) - [Boeing 747-123](https://openairdocs.org/model/boeing-747-123): 2 aircraft (airframe model) - [Boeing 747-251F](https://openairdocs.org/model/boeing-747-251f): 2 aircraft (airframe model) - [Boeing 747-443](https://openairdocs.org/model/boeing-747-443): 2 aircraft (airframe model) - [Boeing 747-438](https://openairdocs.org/model/boeing-747-438): 2 aircraft (airframe model) - [Boeing 747-428](https://openairdocs.org/model/boeing-747-428): 2 aircraft (airframe model) - [Boeing 747-257B](https://openairdocs.org/model/boeing-747-257b): 1 aircraft (airframe model) - [Boeing 747-283B](https://openairdocs.org/model/boeing-747-283b): 1 aircraft (airframe model) - [Boeing 747-121](https://openairdocs.org/model/boeing-747-121): 1 aircraft (airframe model) - [Boeing 747-131](https://openairdocs.org/model/boeing-747-131): 1 aircraft (airframe model) - [Boeing 747-128](https://openairdocs.org/model/boeing-747-128): 1 aircraft (airframe model) - [Boeing 747-273C](https://openairdocs.org/model/boeing-747-273c): 1 aircraft (airframe model) All 24 models: https://openairdocs.org/ad/99-24-16/models.md Every aircraft: https://openairdocs.org/ad/99-24-16/aircraft.md ## Related documents - [Proposed rule 99-NM-46-AD](https://openairdocs.org/proposed/99-NM-46-AD): Notice of proposed rulemaking (NPRM), published Jul 16, 1999 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.