AD 96-03-10

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AD Number:
96-03-10
Document Type:
AD Final Rules
Docket Number:
95-NM-274-AD
Subject Heading:
Airworthiness Directives; Boeing Model 747-400 Series Airplanes
Subject:
Fuel Tube
Status:
Current
Citation:
(Federal Register: February 02, 1996 (Volume 61, Number 23))
Citation Publish Date:
02/02/1996
Effective Date:
02/20/1996
Make:
The Boeing Company
Model:
747-400 Series | 747-400D Series | 747-400F Series
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39 (61 FR 3793 NO. 23 02/02/96)
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 96-03-10
CITATION:   [Federal Register: February 02, 1996 (Volume 61, Number 23)]

PAGE NUMBER:   [Page 3793]

DOCKET NUMBER:   95-NM-274-AD

AMENDMENT:   39-9507

AD NUMBER:   96-03-10

SUBJECT HEADING:   Airworthiness Directives; Boeing Model 747-400 Series Airplanes

ACTION:   Final rule; request for comments

SUMMARY:  
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-400 series airplanes. This action requires an inspection for damage of the fuel tube located in the forward engine strut, and repair, if necessary; installation of a new support bracket and clamps on the power feeder conduit; and an inspection for proper positioning of the power feeder conduit in each engine strut, and adjustment, if necessary. This amendment is prompted by reports of worn fuel tubes that were caused by the power feeder conduit moving and touching the fuel tube. The actions specified in this AD are intended to prevent wear of the fuel tube, which could result in a fuel leak in the engine strut and a consequent fire hazard.

DATES:   Effective February 20, 1996. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of February 20, 1996. Comments for inclusion in the Rules Docket must be received on or before April 2, 1996.

ADDRESSES:  
Submit comments in triplicate to the Federal Aviation Administration (FAA),
Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 95-NM-274-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined 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.

FOR FURTHER INFORMATION CONTACT:  
Stephen S. Oshiro, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington; telephone (206) 227-2793; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION:  
Two operators of Boeing Model 747-400 series airplanes equipped with Rolls Royce engines have reported five incidents of worn engine fuel feed tubes found in the engine struts. In each case, the worn tube was found to be touching the engine power feeder cable conduit in the front of the engine strut. This touching created worn (chafed) areas on the fuel tubes; the worn areas were between 0.0055 and 0.014 inch deep. Investigation revealed that the currently-installed bracket and clamps for the power feeder conduit allow the conduit to rotate and consequently come into contact with the engine fuel feed tube. If this is not prevented, the conduit can wear a hole in the fuel tube, which could result in a fuel leak in the forward strut area. A fuel leak such as this, if not corrected, could pose a fire hazard.

Boeing has issued Alert Service Bulletin 747-28A2190, dated March 23, 1995, which describes procedures for inspecting the fuel tube in each strut for wear or damage, and repairing it, if necessary. It also describes procedures for installing a new support bracket and two new clamps on the power feeder conduit in all four engine struts. The service bulletin also describes procedures for inspecting the power feeder conduit for proper positioning, and adjusting it to obtain maximum clearance between it and the fuel tube.

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent a fuel leak in the forward engine strut. This AD requires (1) an inspection for wear of the fuel tube in the forward engine strut, and repair, if necessary; (2) the installation of a new support bracket and two new clamps on the power feeder conduit; and (3) an inspection for proper positioning of the power feeder conduit, and adjustment, if necessary. The actions are required to be accomplished in accordance with the service bulletin described previously.

None of the Model 747-400 series airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future.

Should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 8 work hours to accomplish the required actions, at an average labor charge of $60 per work hour. The cost of required parts would be $368 per airplane. Based on these figures, the cost impact of this AD would be $848 per airplane.

Since this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.

Comments Invited

Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 95-NM-274-AD." The postcard will be date stamped and returned to the commenter.

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 USC 106(g), 40113, 44701. § 39.13 - [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

REGULATORY TEXT:  
96-03-10 BOEING: Amendment 39-9507. Docket 95-NM-274-AD.

Applicability: Model 747-400 series airplanes equipped with Rolls Royce engines; as listed in Boeing Alert Service Bulletin 747-28A2190, dated March 23, 1995; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 use the authority provided in paragraph (b) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent a fuel leak in the forward engine strut, accomplish the following:

(a) Within 90 days after the effective date of this AD, accomplish the requirements of paragraphs (a)(1), (a)(2), and (a)(3) of this AD in accordance with Boeing Alert Service Bulletin 747- 28A2190, dated March 23, 1995:

(1) Inspect the fuel tube in each engine strut for wear and damage. Prior to further flight, repair any discrepancy found.

(2) Install a new support bracket and new clamps on the power feeder conduit in each engine strut.

(3) Inspect the engine power feeder cable conduit in the front of each engine strut for proper positioning. Prior to further flight, position the conduit to obtain the most clearance between it and the fuel tube.

(b) An alternative method of compliance or adjustment of the compliance time that provides 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

(c) 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.

(d) The inspection and installation shall be done in accordance with Boeing Alert Service Bulletin 747-28A2190, dated March 23, 1995. 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.

(e) This amendment becomes effective on February 20, 1996.

FOOTER: