AD 2000-17-02

This amendment adopts a new airworthiness directive (AD), applicable to all British Aerospace Model BAe 146 and certain Model Avro 146-RJ series airplanes, that requires inspections and torque checks of the stringer crown fittings and bolts at Ribs 0 and 2 of the wings for discrepancies, corrective action, if necessary; and eventual modification of the stringer crown fittings, which terminates the inspections and checks. This amendment is necessary to prevent increased loads on the upper wing skin due to looseness of the stringer fittings and bolts at Ribs 0 and 2 of the wings, which could result in reduced structural integrity of the wings. This action is intended to address the identified unsafe condition.

Final rule.

2000-17-02 BRITISH AEROSPACE REGIONAL AIRCRAFT (Formerly British Aerospace Regional Aircraft Limited, Avro International Aerospace Division; British Aerospace, PLC; British Aerospace Commercial Aircraft Limited): Amendment 39-11875. Docket 99-NM-355-AD.

Applicability: All Model BAe 146 series airplanes; and Model Avro 146-RJ series airplanes, as listed in British Aerospace Service Bulletin SB.57-56, dated September 2, 1999; certificated in any category; except those on which British Aerospace Modification HCM01307A or HCM01307B [Reference Repair Instruction (R.I.L. HC571H9033)] has been accomplished.

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 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 prevent increased loads on the upper wing skin due to looseness of the stringer fittings and bolts at Ribs 0 and 2 of the wings, which could result in reduced structural integrity of the wings, accomplish the following:

Inspections and Modification

(a) Prior to the accumulation of 14,000 total flight cycles, or within 4,000 flight cycles after the effective date of this AD, whichever occurs later: Perform a detailed visual inspection of the stringers and a torque check of the Jo-bolts at Ribs 0 and 2 of the wings for discrepancies (including loose Jo-bolts and stringer crown fittings, fretting of fittings and stringers, and cracking or damage of attachments); in accordance with British Aerospace Service Bulletin SB.57-56, dated September 2, 1999.

(1) If no discrepancy is found, or, if 1, 2, or 3 loose Jo-bolts are found per rib side and no loose crown (dagger) fittings are found (Category 1 or 2, as specified in Table 2 of paragraph D. "Compliance" of the service bulletin), accomplish the actions required in paragraphs (a)(1)(i) and (a)(1)(ii) of this AD.

(i) Repeat the inspection thereafter at the applicable times specified in Table 2, until accomplishment of the actions required by paragraph (a)(1)(ii).

(ii) Prior to accumulation of 40,000 total flight cycles, or within 4,000 flight cycles after the effective date of this AD, whichever occurs later: Modify all stringer crown fittings at Ribs 0 and 2 of the wings (including inspections, repairs, and installation of oversize interference fit fasteners per R.I.L. HC571H9033) in accordance with the service bulletin, except as required by paragraph (b) of this AD. This modification terminates the requirements of this AD.

(2) If any other discrepancy is found, as specified in Table 2 (Categories 3 through 6): At the applicable times specified in Table 2, repeat the inspection thereafter, and modify all crown fittings at Ribs 0 and 2 of the wings (including inspections, repairs, and installation of oversize interference fit fasteners per R.I.L. HC571H9033); in accordance with the service bulletin, except as required by paragraph (b) of this AD. This modification terminates the requirements of this AD.

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."

Approved Repairs

(b) Where British Aerospace Service Bulletin SB.57-56, dated September 2, 1999, specifies to contact the manufacturer for a repair, prior to further flight, repair in accordance with a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Civil Aviation Authority of the United Kingdom (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.

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. 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) Except as provided by paragraph (b) of this AD, the actions shall be done in accordance with British Aerospace Service Bulletin SB.57-56, dated September 2, 1999, including Repair Instruction (R.I.L.) HC571H9033, Issue 3, dated April 23, 1999. (Note: Only the first page of Repair Instruction (R.I.L.) HC571H9033 shows the issue level anddate; no other page contains this information.)

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 004-09-99.

(f) This amendment becomes effective on October 3, 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 certain Model Avro 146-RJ series airplanes was published in the Federal Register on June 28, 2000 (65 FR 39831). That action proposed to require inspections and torque checks of the stringer crown fittings and bolts at Ribs 0 and 2 of the wings for discrepancies, corrective action, if necessary; and eventual modification of the stringer crown fittings, which would terminate the inspections and checks.

Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion
The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact
The FAA estimates that 20 airplanes of U.S. registry will be affected by this AD.

It will take approximately 8 work hours per airplane to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the required inspection on U.S. operators is estimated to be $9,600, or $480 per airplane, per inspection cycle. It will take approximately 450 work hours per airplane (including access and close) to accomplish the required modification, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the required modification on U.S. operators is estimated to be $540,000, or $27,000 per airplane.

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.

Regulatory Impact
The regulations adopted herein will not havea 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."

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: