Federal Aviation Administration, DOT.Start Printed Page 75592
This amendment adopts a new airworthiness directive (AD), applicable to all Airbus Model A319, A320, and A321 series airplanes, that requires a revision to the Airplane Flight Manual; inspection to detect damage of the wiring and adjacent structure along the length of the fairing of the fuel boost pump; corrective actions, if necessary; and modification of the fuel pump wire and fairing. The actions specified by this AD are intended to prevent electrical arcing of the fuel boost pump wire, which could result in wing structural damage, fire, and/or fuel vapor explosion. This action is intended to address the identified unsafe condition.
Effective January 8, 2001.
The service information referenced in this AD may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Tim Dulin, Aerospace Engineer, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2141; fax (425) 227-1149.End Further Info End Preamble Start Supplemental 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 all Airbus Model A319, A320, and A321 series airplanes was published in the Federal Register on August 24, 2000 (65 FR 51560). That action proposed to require a revision to the Airplane Flight Manual (AFM); inspection to detect damage of the wiring and adjacent structure along the length of the fairing of the fuel boost pump; corrective actions, if necessary; and modification of the fuel pump wire and fairing.
Action Since the Issuance of Proposed AD
The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, has issued French airworthiness directive 2000-419-154(B), dated October 4, 2000. That airworthiness directive includes a procedure for revising the AFM. In addition, if a fuel boost pump malfunctions, airworthiness directive procedures specify removing the wiring fairing to inspect the electrical wiring, fairing, and wing skin within the fairing area; and corrective actions, if necessary. Procedures also include a reporting requirement.
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
One commenter supports the AFM revision specified by the proposed AD.
Request To Delete the Inspection Requirement
Five commenters request deleting the requirement in paragraph (b) of the proposed AD, which specifies an inspection of the wiring and adjacent structure along the length of the fairing. All of the commenters are concerned that the inspection could induce more damage, even if operators exercise caution as recommended in the proposed AD.
One commenter states that in-service experience indicates that arcing of the underwing fuel pump wiring is mainly linked to poor maintenance action rather than to damage due to vibration and chafing. That commenter considers that most of the damage has occurred during fairing replacement when the fuel boost pump wire can be pinched and damaged. A second commenter concurs and suggests that the inspection specified in paragraph (b) be included in paragraph (c) of this AD, in case a circuit breaker tripped. A third commenter considers that removing the fairing is unnecessary, and that such action may cause needless damage to the wiring upon re-installation. In addition, the design of the system is such that, if a wire is trapped, the circuit breaker will trip and avert danger. A fourth commenter considers that the inspection increases the probability of inducing a fault despite heightened awareness, and that the inspection should be required only when terminating action is identified and applied before reinstalling the fairing. A fifth commenter notes that, if a fuel pump circuit breaker trips, a full inspection of the wiring underneath the fairing is required prior to further use of that pump. Further, that requirement should be enough to remove the need for the inspection specified by the proposed AD.
The FAA does not concur that the detailed visual inspection in paragraph (b) of the proposed AD should be deleted. We consider that the benefit from the one-time inspection outweighs the risk of wire damage during reassembly of the fairing. We have received reports of damaged wiring and arcing to the fuselage skin on in-service and newly manufactured airplanes, which indicate that additional airplanes may have pre-existing wire damage. In addition, we have found that intermittent arcing, which gradually eroded the adjacent aluminum structure and penetrated into the fuel tank, has occurred on other model airplanes without tripping the circuit breaker. Therefore, the possibility that such arcing damage could result in fuel leaking on top of the arcing wire justifies the one-time inspection.
We do not agree that the inspection increases the probability of inducing damage. We point out that the original fairing installations were done without any installation precautions. However, to ensure that wiring damage is not induced during replacement action, we included specific instructions cautioning operators to take special care when replacing the fairing. Those instructions, which were added to paragraph (b) of the proposed AD, make it unlikely that improper installation of the fairing will occur.
For these reasons, we consider that the one-time detailed visual inspection required by paragraph (b) of this AD is needed to ensure that no critical condition exists in the fleet. Paragraph (b) has not been deleted in the final rule.
Requests To Specify a Difference Regarding the Inspection Requirement
Two commenters state that, although the proposed AD specifies a one-time inspection (of all Model A319, A320, and A321 series airplanes), the previously referenced French airworthiness directive does not specify such an inspection. This difference should be included in the final rule so that other Civil Aviation Authorities can decide on the corrective actions they consider appropriate, and so that any confusion for the operators is avoided.
We concur with the request to specify this difference in the final rule. Note 4 of the final rule includes a statement that notifies operators of the difference between this AD and the French airworthiness directive.
Request To Add a Reference to an Airplane Flight Manual (AFM)
One commenter requests adding a reference to the DGAC-approved AFM Temporary Revision (TR) 2.05.00/31 in paragraph (a) of the proposed AD as a means of compliance. That TR includes the same basic requirements defined in paragraph (a) of the proposed AD.
We concur with this request, and agree that the TR includes the same basic requirements defined in paragraph (a) of the proposed AD. Paragraph (a) of the final rule now states that “This may Start Printed Page 75593be accomplished by inserting a copy of this AD or Airbus Temporary Revision 2.04.00/31 into the AFM.”
Requests To Delete the Modification Requirement
Two commenters request deleting the modification requirement specified by paragraph (e) of the proposed AD. One commenter states that a final fix is being developed and should be available by the end of this year. When the final fix is available, a new AD should be issued to mandate the modification. Another commenter considers that the modification should be required within 18 months after the modification is made available. However, since the modification is not currently available, that requirement should be removed from the AD.
We partially concur with the requests regarding the modification requirement in paragraph (e) of the proposed AD. Although a final modification has not been completely defined, we consider it imperative to speed up the development and installation of a modification to prevent any chance of the wires being damaged either during removal and replacement of the fairing, or due to vibration while the airplane is in service. We have determined that allowing an additional 6 months for development and testing of the modification is appropriate to ensure that the modification is effective and to allow enough time for incorporating the modification on in-service airplanes. The compliance time for the modification is extended from 18 to 24 months in paragraph (e) of the final rule.
Request To Revise the Cost Estimate
The Air Transport Association (ATA) of America, on behalf of one of its members, states that re-installation of the fairing, per the “Installation of Fuel Pump Fairing” section of Airbus Airplane Maintenance Manual (AMM) Task 28-21-49-400-001, requires the use of a sealant with a cure time of up to 16 hours. The commenter adds that the sealant curing process will have a severe economic impact on the airlines, which does not appear to be addressed in the Cost Impact paragraph of the NPRM.
We infer that the commenter requests a revision of the cost estimate in the proposed AD, but we do not concur that a revision to the cost estimate is necessary. While we agree that the previously referenced AMM specifies the use of sealant to reassemble the front fairing and cover plate, upon further review we have determined that it is not necessary to remove the front fairing and cover plate to inspect the portion of the wiring where damage has been found. Therefore, we have revised paragraph (b) in the final rule to require removal of only the “rear and intermediate” fairing. With this change, there is no requirement to apply sealant during accomplishment of the action required by paragraph (b) of this AD. No change to the cost estimate was made in the final rule.
Request To Delete Paragraph (c)
One commenter requests that paragraph (c) of the proposed AD be deleted from the final rule. The airplane trouble-shooting manual (TSM) addresses what to do when a circuit breaker trips and includes procedures for checking the wiring, if necessary. The commenter adds that mandating the removal of the fairing to check the wiring when it is unnecessary may induce problems. In the past, the TSM procedure has been used to effectively locate any arcing of the pump wiring.
We do not concur that paragraph (c) should be deleted from this AD. While we agree that the TSM includes a procedure for checking the continuity of the wire, the check may not detect an exposed wire condition. In addition, there have been cases where the wire was not inspected and was later found to be damaged. Therefore, we consider that an inspection to determine the condition of the wire is necessary to ensure that no arcing condition exists. Paragraph (c) was not deleted in the final rule.
Request To Revise the Repair Requirements
One commenter recommends revising paragraph (b)(2) of the proposed AD to include a reference to the Airbus Standard Repair Manual (SRM), and points out that paragraph (b)(1) of the proposed AD references standard practices of the manufacturer's Aircraft Wiring Manual. The commenter notes that, if any damage beyond SRM limits is found, [the commenter's] procedures specify seeking FAA or DGAC repair approval for structures that are the subject of AD's.
We concur with the request to revise the repair requirements. Because the SRM is approved by the DGAC, it may be used as the approved data source to repair any damage that does not exceed the limits specified in the SRM. We have revised paragraph (b)(2) in the final rule to include the SRM as another approved method for repairing the airplane structure.
Explanation of Change Made to Proposal
We have clarified the inspection requirement contained in the proposed AD.
Although NOTE 2 in the proposal specified a detailed inspection, we have revised this final rule to clarify that its intent is to require a detailed visual inspection. NOTE 2 of the final rule has been changed accordingly.
Editorial Changes to the Final Rule
Airbus advises that the circuit breakers for the wing fuel tank pump are designated as 1QA, 2QA, 7QA, and 8QA. We have added these circuit breaker designators to paragraph (a) of the final rule.
Airbus also advises that the Aircraft Wiring Manual (AWM), Standard Practices, Chapter 20, includes procedures for repairing damaged wire. As a result of this information, we have added repair to the existing replacement action as another method of compliance in paragraph (b)(1) of the final rule. We have determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD. This change provides operators with an option to either repair or replace the wire per the AWM.
After careful review of the available data, including the comments noted above, we have determined that air safety and the public interest require the adoption of the rule with the changes described previously. These changes will neither increase the economic burden on any operator nor increase the scope of the AD.
We estimate that 306 Model A319, A320, and A321 series airplanes of U.S. registry will be affected by this AD.
It will take approximately 1 work hour per airplane to accomplish the required AFM revision, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the AFM revision on U.S. operators is estimated to be $18,360, or $60 per airplane.
It will take approximately 2 work hours per airplane to accomplish the required inspection (including time to remove the fairing), at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the wiring inspection on U.S. operators is estimated to be $36,720, or $120 per airplane.
Since the manufacturer has not yet developed a modification commensurate with the requirements of Start Printed Page 75594this AD, we are unable at this time to provide specific information as to the number of work hours or cost of parts that will be required to accomplish the modification. The compliance time of 24 months should provide ample time for the development, approval, and installation of an appropriate modification.
The cost impact figures discussed above are 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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.
The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.
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.Start List of Subjects
List of Subjects in 14 CFR Part 39
- Air transportation
- Aviation safety
Adoption of the AmendmentStart Amendment Part
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:End Amendment Part Start Part
PART 39—AIRWORTHINESS DIRECTIVESEnd Part Start Amendment Part
1. The authority citation for part 39 continues to read as follows:End Amendment Part
2. Section 39.13 is amended by adding the following new airworthiness directive:End Amendment Part
2000-24-08 Airbus Industrie: Amendment 39-12015. Docket 2000-NM-227-AD.
Applicability: All Model A319, A320, and A321 series airplanes; certificated in any category.
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 per paragraph (f) 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 electrical arcing of the fuel boost pump wire, which could result in wing structural damage, or fire and/or fuel vapor explosion, accomplish the following:
Airplane Flight Manual (AFM) Revision
(a) Within 10 days after the effective date of this AD, revise the Limitations Section of the FAA-approved AFM to include the following which may be accomplished by inserting a copy of this AD or Airbus Temporary Revision 2.04.00/31 into the AFM:
If circuit breaker 1QA, 2QA, 7QA, and 8QA for any wing tank fuel boost pump is tripped, do not reset.”
(b) Within 90 days after the effective date of this AD: For each fuel boost pump, remove the rear and intermediate fairings located on the lower wing skin and perform a detailed visual inspection of the wiring and the adjacent structure along the length of the fairings. Inspect to detect damage to the wires including chafed, pinched, or melted wires, and any signs of arcing damage to the structure. When replacing the fairing following the inspection, take care not to pinch or otherwise damage the wiring of the fuel boost pumps; incorrect replacement of the fairing could cause damage to the wiring.
(1) If any damage to the wire, as described in paragraph (b) of this AD, is detected: Prior to further flight, either repair the wire or replace the wire with new wire per the manufacturer's Aircraft Wiring Manual, Standard Practices, Chapter 20. Submit a report at the time specified and per paragraph (d) of this AD.
(2) If any arcing damage to the structure is detected: Prior to further flight, repair the damaged structure per the airplane Structural Repair Manual or a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France (or its delegated agent). For a repair method to be approved by the Manager, International Branch, ANM-116, as required by this paragraph, the Manager's approval letter must specifically reference this AD. Submit a report at the time specified and per paragraph (d) of this AD.
For the purposes of this AD, a detailed visual inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”
(c) As of the effective date of this AD: For any fuel boost pump on which circuit breaker 1QA, 2QA, 7QA, and 8QA of the pump has tripped, prior to further use of that pump, accomplish the inspection and applicable corrective actions specified by paragraph (b) of this AD.
(d) If any damage is detected during any inspection required by paragraphs (b) and (c) of this AD: Within 10 days after accomplishing that inspection, submit a report of the inspection findings to the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; fax (425) 227-1149. The report must include a description of the damage found, the airplane serial number, and the number of landings and flight hours on the airplane. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.
(e) Within 24 months after the effective date of this AD: Modify the fuel pump wire and fairing, per a method approved by the Manager, International Branch, ANM-116.
Alternative Methods of Compliance
(f) 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, International Branch, ANM-116. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.Start Printed Page 75595
Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.
Special Flight Permits
(g) Special flight permits may be issued per 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.
The subject of this AD is addressed in French airworthiness directive 2000-419-154(B), dated October 4, 2000. Operators should note that, although this AD requires a one-time detailed visual inspection, the French airworthiness directive does not mandate such an inspection.
(h) This amendment becomes effective on January 8, 2001.Start Signature
Issued in Renton, Washington, on November 22, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 00-30394 Filed 12-1-00; 8:45 am]
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