Airworthiness Directives; Airbus Model A330 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 2000-25-53, which was sent previously to all known U.S. owners and operators of Airbus Model A330 series airplanes by individual notices. This AD requires either repetitive detailed visual inspections or repetitive borescopic inspections to detect cracking or other damage of the barrel nuts of the engine aft mount; and replacement of any cracked nut and its associated bolt with a new nut and bolt, or replacement of all 4 nuts and their associated bolts if two or more nuts on the same engine mount are found cracked. This action is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to detect and correct cracking of the aft engine mount nut, which could result in reduced structural integrity of the engine-to-pylon aft mount assembly, or, in the case of multiple cracked nuts, possible loss of an engine.

DATES:

Effective January 2, 2001, to all persons except those persons to whom it was made immediately effective by emergency AD 2000-25-53, issued December 9, 2000, which contained the requirements of this amendment.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of January 2, 2001.

Comments for inclusion in the Rules Docket must be received on or before January 29, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-399-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-iarcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2000-NM-399-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The applicable service information may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. 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:

Tim Backman, Aerospace Engineer, International Branch, ANM-116, FAA, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2797; fax (206) 227-1149.

SUPPLEMENTARY INFORMATION:

On December 9, 2000, the FAA issued emergency AD 2000-25-53, which is applicable to certain Airbus Model A330 series airplanes. That action was prompted by issuance of mandatory continuing airworthiness information by the Direction Générale de l'Aviation Civile (DGAC), which is the airworthiness authority for France.

The DGAC recently notified the FAA that an unsafe condition may exist on certain Airbus Model A330 series airplanes. The DGAC advises that there have been at least 5 occurrences of cracked aft engine mount nuts with two found broken (having a crack from the top to the bottom of the nut). Analysis of failed aft engine mount nuts has not yet identified the root cause; however, the cracks resulted from tensile overstress. The DGAC further advises that use of an anti-seize compound, rather than engine oil, for bolt/nut lubrication decreases the frictional loads on the threads of the bolt and nut, and significantly increases the preload for a given torque value. If excessive torque is applied to the bolt, the resultant preload on the bolt and nut can cause overstress and failure of the nut. This condition, if not corrected, could result in reduced structural integrity of the engine-to-pylon aft mount assembly, or, in the case of multiple cracked nuts, possible loss of an engine.

Explanation of Relevant Service Information

Airbus has issued All Operators Telex (AOT) A330-71A3014, dated December 8, 2000, which describes procedures for repetitive detailed visual or borescopic inspections to detect cracking and other damage of the barrel nuts of the engine aft mount. Corrective actions include replacing any damaged nut and its associated bolt with a new nut and bolt having the same part number. If two or more nuts on the same engine mount are found broken (i.e., having a crack from the top to the bottom of the nut), the AOT prescribes replacement of all four nuts and their associated bolts. The DGAC classified this AOT as mandatory and issued French telegraphic airworthiness directive T2000-523-134(B), dated December 8, 2000, to ensure the continued airworthiness of these airplanes in France.

Airbus AOT A330-71A3014, dated December 8, 2000, refers to Pratt & Whitney Service Bulletin PW4G-100-71-16, Revision 1, dated September 15, 1999, as an additional source of service information for replacing the nuts and bolts.

FAA's Conclusions

This airplane model is manufactured in France and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of the Requirements of the Rule

Since the unsafe condition described is likely to exist or develop on other airplanes of the same type design registered in the United States, the FAA issued emergency AD 2000-25-53 to detect and correct cracking of the aft engine mount nut, which could result in reduced structural integrity of the engine-to-pylon aft mount assembly, or, in the case of multiple cracked nuts, possible loss of an engine. The AD requires either repetitive detailed visual inspections or repetitive borescopic inspections to detect cracking or other damage of the barrel nuts of the engine aft mount; and replacement of any cracked nut and its associated bolt with a new nut and bolt, or replacement of all 4 nuts and their associated bolts if two or more nuts on the same engine mount are found cracked. The actions are required to be accomplished in accordance with the AOT previously described.

Explanation of Applicability

This AD is applicable to Airbus Model A330 series airplanes equipped with Pratt & Whitney 4000 series engines fitted with engine aft mount nuts and bolts installed in accordance with Airbus Modification 46948 (installed on in-service airplanes per Airbus Service Bulletin A330-71-3012). The modification involves installing bolts and nuts made of MP159 material, to replace nuts and bolts made of the INCO718 material previously used. The Pratt & Whitney service bulletin, described previously, describes instructions for installing these parts, as referenced by Airbus Service Bulletin A330-71-3012.

Editorial Changes

Certain typographical errors were discovered in the version of AD 2000-25-53 that was sent previously to U.S. owners and operators of Airbus Model A330 series airplanes. Specifically, there were two notes identified as Note “2” and two notes identified as Note “3.” The notes have been correctly identified in this AD.

Interim Action

This is considered to be interim action. The manufacturer reports that further analysis is required to identify the root cause of the barrel nut failure. Continued inspections will provide better insight into the nature, cause, and prevalence of the cracking. If further action is identified to address the unsafe condition, the FAA may consider further rulemaking.

Determination of Rule's Effective Date

Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual notices issued on December 9, 2000, to all known U.S. owners and operators of Airbus Model A330 series airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective as to all persons.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an 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 2000-NM-399-AD.” The postcard will be date stamped and returned to the commenter.

Regulatory Impact

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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket.

A copy of it, if filed, 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.

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

2000-25-53 Airbus Industrie: Amendment 39-12051. Docket 2000-NM-399-AD.

Applicability: Model A330 series airplanes equipped with Pratt & Whitney 4000 series engines, certificated in any category; fitted with engine aft mount nuts and bolts installed in accordance with Airbus Modification 46948 (installed on in-service airplanes per Airbus Service Bulletin A330-71-3012).

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 (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.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct cracking of the aft engine mount nut, which could result in reduced structural integrity of the engine-to-pylon aft mount assembly, or, in the case of multiple cracked nuts, possible loss of an engine, accomplish the following:

Inspection

(a) Before the next flight, perform either a detailed visual or borescopic inspection to detect cracking or other damage of all 4 barrel nuts of each engine aft mount, in accordance with paragraph 4.2.1 of Airbus All Operators Telex (AOT) A330-71A3014, dated December 8, 2000. If any cracking or damage is detected, before further flight, replace nuts and their associated bolts, as applicable, in accordance with paragraph 4.2.2 of the AOT. Repeat the inspection thereafter at least every 50 flight cycles.

Note 2:

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.”

Note 3:

Airbus AOT A330-71A3014, dated December 8, 2000, refers to Pratt & Whitney Service Bulletin PW4G-100-71-16, Revision 1, dated September 15, 1999, as an additional source of service information for replacing the nuts and bolts.

Alternative Methods of Compliance

(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, International Branch, ANM-116, Transport Airplane Directorate, FAA. 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.

Note 4:

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

(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.

Incorporation by Reference

(d) The actions shall be done in accordance with Airbus All Operators Telex A330-71A3014, dated December 8, 2000. 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 Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. 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.

Note 5:

The subject of this AD is addressed in French telegraphic airworthiness directive T2000-523-134(B), dated December 8, 2000.

Effective Date

(e) This amendment becomes effective on January 2, 2001, to all persons except those persons to whom it was made immediately effective by emergency AD 2000-25-53, issued December 9, 2000, which contained the requirements of this amendment.