AD 2000-05-28

This amendment adopts a new airworthiness directive (AD), applicable to all British Aerospace Model BAe 146 and Avro 146-RJ series airplanes, that requires a one-time inspection to detect cracking or corrosion of the forward attachment bolts of the engine pylon to wing interface, and corrective action, if necessary. It also requires re-installation with re-protected and sealed bolts torqued to a lower level. This amendment 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 or corrosion of the forward attachment bolts of the engine pylon to wing interface, which could result in reduced structural integrity of the engine pylon attachment.

Final rule

2000-05-28 BRITISH AEROSPACE REGIONAL AIRCRAFT (Formerly British Aerospace Regional Aircraft Limited, Avro International Aerospace Division; British Aerospace, PLC; British Aerospace Commercial Aircraft Limited): Amendment 39-11638. Docket 99-NM-347-AD.

Applicability: All Model BAe 146 and Avro 146-RJ series airplanes, 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 detect and correct cracking or corrosion of the forward attachment bolts of the engine pylon to wing interface, which could result in reduced structural integrity of the engine pylon attachment, accomplish the following:

Inspection and Corrective Action
(a) Within 4 years since date of manufacture, or within 2,000 flight cycles after the effective date of this AD, whichever occurs later: Except as provided by paragraph (b) of this AD, perform applicable inspections (dye penetrant, magnetic particle, and detailed visual) to detect discrepancies (including damage, cracking, and corrosion) of the forward attachment bolts of the engine pylon to wing interface on each engine, in accordance with British Aerospace Service Bulletin SB.54-10, dated September 16, 1999. If any discrepancy is detected, prior tofurther flight, perform applicable corrective actions in accordance with the service bulletin.

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."

(b) Replacement of all bolts with new bolts in accordance with British Aerospace Service Bulletin SB.54-10, dated September 16, 1999, within the compliance time specified in paragraph (a) of this AD, is an acceptable alternative for compliance with the requirements of paragraph (a), provided all installation methods (including retorquing the bolts at a lower level, and applying sealant to the bolts) specified in the service bulletin are followed.

Alternative Methods of Compliance
(c) 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, 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, International Branch, ANM-116.

NOTE 3: 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
(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 actions shall be done in accordance with British Aerospace Service Bulletin SB.54-10, dated September 16, 1999. 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 British Aerospace Regional Aircraft American Support, 13850 Mclearen Road, Herndon, Virginia 20171. 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 4: The subject of this AD is addressed in British airworthiness directive 006-09-99.

(f) This amendment becomes effective on April 26, 2000.

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 British Aerospace Model BAe 146 and Avro 146-RJ series airplanes was published in the Federal Register on December 15, 1999 (64 FR 69967). That action proposed to require a one-time inspection to detect cracking or corrosion of the forward attachment bolts of the engine pylon to wing interface, and corrective action, if necessary. That action also proposed to require re-installation with re-protected and sealed bolts torqued to a lower level.

Comments Received
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Request to Revise Cost Impact Information
One commenter, an operator, requests that the cost impact information in the proposed AD be increased from "20 work hours (including removal and reinstallation of the engines)" to 112 work hours. The commenter states that, as an experienced operator, it estimates the time necessary to remove and replace just one engine is approximately 8 to 10 work hours. The commenter suggests that an appropriate estimate for all actions required by the AD is approximately 112 work hours, including hours for removal and replacement of four engines and the pylon attachment bolts, as well as inspection of the bolts and removal of corrosion.

The FAA partially concurs. The estimate of 20 work hours provided in the AD was based on the estimate of work hours specified in British Aerospace Service Bulletin SB.54-10, dated September 16, 1999 (which was referenced in the proposed AD and cited in this final rule as the appropriate source of service information). However, the FAA has determined that such an estimate includes only the time required to accomplish the inspections required by this AD, and does not include the time necessary for removal and reinstallation of all four engines or the time for accomplishment of corrective actions if corrosion is found. The FAA has revised the cost impact information, below, by removing the parenthetical statement indicating that the 20 work hours includes engine removal and reinstallation. However, because the economic analysis of the AD is limited to the cost of actions actually required by the rule, it does not typically include the costs of "indirect" or "on-condition" actions, such as hours necessary for access and close, or for repairs. Therefore, no further change to the cost impact information is necessary.

Request for Alternative Method of Compliance
The same commenter requests that the proposed AD include a provision for the replacement of the pylon attachment bolts with new bolts as an alternative to performing the inspection. The commenter notes that such a provision is not specified in the referenced service bulletin or in the proposed AD, but states thatthis option should be available at the operator's discretion as an alternative method of compliance.

The FAA concurs. The FAA has reviewed the acceptability of the proposed alternative method of compliance with the manufacturer and with the Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom. Based on that input, the FAA has determined that replacement of all pylon attachments bolts with new bolts is an acceptable alternative to performing the inspection required by this AD, provided that the installation methods specified in the service bulletin are followed. Such installation methods include retorquing the new bolts to a lower level, and applying sealant to the bolts. A new paragraph (b) has been added to the final rule to provide this alternative as an acceptable means of complying with the requirements of this AD.

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 with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
The FAA estimates that 35 airplanes of U.S. registry will be affected by this AD, that it will take approximately 20 work hours per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $42,000, or $1,200 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 a substantial direct effect on the States, on the relationship betweenthe 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."

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 39.13 is amended by adding the following new airworthiness directive: