AD 96-14-02

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, that requires a visual inspection to verify proper clearance between the number 18 fuel nozzle secondary transfer fuel tube and the pylon drain tube of the engine, and various follow-on actions. This amendment also requires the installation of clamps and associated fasteners between the environmental control system (ECS) controller tube and the pylon drain tube. This amendment is prompted by reports of chafing of the number 18 fuel nozzle secondary transfer fuel tube of the engine due to an improperly installed or loose pylon drain tube. The actions specified by this AD are intended to prevent such chafing, which could lead to subsequent fuel leakage and a possible engine fire.

Final rule

96-14-02 BOEING: Amendment 39-9684. Docket 95-NM-154-AD. \n\n\tApplicability: Model 767 series airplanes having line position 1 through 329, inclusive; equipped with Pratt & Whitney Model JT9D-7R4 engines; certificated in any category. \n\n\tNOTE 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 (b) 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. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent chafing of the number 18 fuel nozzle secondary transfer fuel tube of the engine, and subsequent fuel leakage and possible engine fire, accomplish the following: \n\n\t(a)\tWithin 6 months after the effective date of this AD, perform a visual inspection to verify proper clearance (0.5 inch) between the number 18 fuel nozzle secondary transfer fuel tube and the pylon drain tube of the engine. \n\n\t\t(1)\tIf the clearance is equal to or greater than 0.5 inch: Prior to further flight, install clamps and associated fasteners between the environmental control system (ECS) and the pylon drain tube, in accordance with Boeing Alert Service Bulletin 767-71A0082, dated July 6, 1995. \n\n\t\t(2)\tIf the clearance is less than 0.5 inch: Prior to further flight, perform a visual inspection to detect damage of the number 18 fuel nozzle secondary transfer fuel tube and the pylon drain tube. \n\n\t\t\t(i)\tIf no damage is detected; or if any damage to the number 18 fuel nozzle secondary transfer tube is less than or equal to 0.003 inch deep, as specified in Section 72-09-71 of Pratt & Whitney JT9D Engine Manual, and if any damage to the drain tube is less than or equal to 0.004 inch deep, as specified in the Boeing 767 Maintenance Manual 28-22-07: Prior to further flight, relocate the pylon drain tube to meet the 0.5 inch specification. After accomplishing the relocation, prior to further flight, install the clamps and associated fasteners between the ECS and the pylon drain tube, in accordance with Boeing Alert Service Bulletin 767-71A0082, dated July 6, 1995. \n\n\t\t\t(ii)\tIf any damage to the number 18 fuel tube is greater than 0.003 inch deep, as specified in Section 72-09-71 of the Pratt & Whitney JT9D Engine Manual; or if any damage to the drain tube is greater than 0.004 inch deep, as specified in the Boeing 767 Maintenance manual 28-22-07: Prior to further flight, repair or replace the damaged tube, in accordance with Section 28-00-10 of the Boeing 767 Overhaul Manual. After accomplishing the repair or replacement, prior to further flight, install the clamps and associated fasteners between the ECS and the pylon drain tube, in accordance with Boeing Alert Service Bulletin 767-71A0082, dated July 6, 1995. \n\n\t(b)\tAn 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. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(c)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(d)\tThe installation of the clamps and associated fasteners shall be done in accordance with Boeing Alert Service Bulletin 767-71A0082, dated July 6, 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. \n\n\t(e)\tThis amendment becomes effective on August 9, 1996.

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 767 series airplanes was published in the Federal Register on January 31, 1996 (61 FR 3340). That action proposed to require a visual inspection to verify proper clearance between the number 18 fuel nozzle secondary transfer fuel tube and the pylon drain tube of the engine, and various follow-on actions. That action also proposed to require the installation of clamps and associated fasteners between the environmental control system (ECS) controller tube and the pylon drain tube. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.\n\n Support for the Proposal \n\n\tOne commenter supports the proposal. \n\nRequest to Revise Description of Affected Component \n\n\tOne commenter, Boeing, requests that all references in the proposed rule to the "ECS" controller tube be changed to "the high pressure controller muscle air tube." The commenter states that the high pressure controller and muscle air tube are components of the airplane pneumatic system, which provides engine bleed air to various airplane systems, including the ECS. \n\n\tThe FAA agrees with the commenter's suggestion that the revised wording may be a more accurate description of the subject component. However, the service information (Boeing Service Bulletin 767-71A0082) that is referenced in the AD uses the term "ECS controller tube" throughout the procedures it contains relative to the modification. In light of this, the FAA finds that using the term "ECS controller tube" in the final rule will maintain consistency with the terminology used in the referenced service bulletin and, thereby, will avoid confusion. \n\nRequest to Revise Description of Service History \n\n\tThis same commenter requests thatthe description of the incidents that prompted the AD be revised. The commenter points to a specific statement that appeared in the Discussion section of the preamble to the notice: "In the engine fire incident, investigation revealed that the cause of the chafing was attributed to the installation of the wrong engine fuel manifold, which did not provide for adequate clearance for the fuel tube." The commenter states that subsequent investigation of this particular incident revealed that an acceptable clearance could be maintained even if the wrong configuration of number 18 fuel tube was installed. The contributing factor to the chafing of the number 18 fuel tube was the mis-installation of the pylon drain tube. \n\n\tThe FAA acknowledges this new information. However, it in no way affects the intent of or need for this AD. Since the Discussion section is not repeated in the final rule, no change to the rule is necessary. \n\nRequest to Clarify Damage Specifications \n\n\tThis same commenter requests that proposed paragraph (a)(2) be revised to clarify the amount of damage to the number 18 fuel tube and the pylon drain tube of the engine that would require replacement or repair of those items. The commenter points out that the damage specifications indicated in the proposal are different from those specified in both the 767 Maintenance Manual and the Pratt & Whitney JT9D Engine Manual. \n\n\tThe FAA concurs that clarification is necessary. Based on information contained in the two manuals referenced by the commenter, the FAA finds that repair or replacement must be accomplished if damage to the number 18 fuel tube is greater than 0.003 inch, and if damage to the pylon drain tube is greater than 0.004 inch. Paragraphs (a)(2)(i) and (a)(2)(ii) of the final rule have been changed accordingly. Additionally, those paragraphs have been revised to include reference to the 767 Maintenance Manual and the Pratt & Whitney JT9D Engine Manual as sources of information relative to damage measurements.\n\n Request to Extend Compliance Time \n\n\tOne commenter requests that the compliance time for accomplishing the inspection be extended from the proposed 6 months to 12 months. The commenter, a non-U.S. operator, requests this extension in order to accommodate the modification of a number of engines in its fleet that currently are equipped with different clamps. \n\n\tThe 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 not only the degree of urgency associated with addressing the subject unsafe condition, but the availability of required parts and the practical aspect of accomplishing the inspection and installing the modification within an interval of time that parallels normally scheduled maintenance for the majority of affected operators. The FAA has found that an ample number of modification parts will be available to accommodate the affected fleet within the 6-month compliance period. In light of these factors, the FAA finds that the compliance time, as proposed, is appropriate. However, under the provisions of paragraph (b) of the final rule, the FAA may approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety.\n\n Conclusion \n\n\tAfter 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 with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 93 Model 767 series airplanes equipped with Pratt & Whitney Model JT9D-7R4 engines of the affected design in the worldwide fleet. The FAA estimates that 30 airplanes of U.S. registry will be affected by this AD, that it will take approximately 4 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 $31 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $8,130, or $271 per airplane. \n\n\tThe 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. \n\nRegulatory Impact \n\n\tThe 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 implicationsto warrant the preparation of a Federalism Assessment. \n\n\tFor 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."\n\n List of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\n\tAccordingly, 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: \n\nPART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 - (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: