AD 2000-05-27

This amendment supersedes an existing airworthiness directive (AD), applicable to certain British Aerospace Model BAe 146-100A, -200A, and -300A series airplanes, that currently requires either a one-time nondestructive test (NDT) inspection or a detailed visual inspection for cracking of the fuselage skin in the vicinity of frame 29 between stringers 12 and 13, and repair, if necessary. This amendment requires that the current thresholds for these inspections be reduced and that repetitive inspections be performed. 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 fatigue cracking of the fuselage skin in the specified area, which could result in reduced structural integrity of the airplane.

Final rule

2000-05-27 BRITISH AEROSPACE REGIONAL AIRCRAFT (Formerly British Aerospace Regional Aircraft Limited, Avro International Aerospace Division; British Aerospace, PLC; British Aerospace Commercial Aircraft Limited): Amendment 39-11637. Docket 99-NM-237-AD. Supersedes AD 98-21-06, Amendment 39-10814.

Applicability: Model BAe 146-100A, -200A, and -300A series airplanes; as listed in British Aerospace Service Bulletin SB.53-144, dated April 27, 1998, or Revision 1, dated May 21, 1999; 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 (d) 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 fatigue cracking of the fuselage skin in the vicinity of frame 29 between stringers 12 and 13, which could result in reduced structural integrity of the airplane, accomplish the following:

Inspections
(a) Perform either a nondestructive test (NDT) inspection or a detailed visual inspection for cracking of the fuselage skin in the vicinity of frame 29 between stringers 12 and 13, in accordance with British Aerospace Service Bulletin SB.53-144, dated April 27, 1998, or Revision 1, dated May 21, 1999, at the earlier of the applicable times specified in paragraphs (a)(1) and (a)(2).

NOTE 2: The actions defined in the original issue and Revision 1 of the service bulletin are identical. However, the compliance times and effectivity groupings are different. Accomplishment of either revision level, at the earlier of the applicable compliance times of paragraphs (a)(1) and (a)(2) of this AD, is acceptable for compliance with the requirements of paragraph (a) of this AD.

NOTE 3: For the purposes of this AD, a detailed 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."

(1) For airplanes identified in the specified paragraph of Service Bulletin SB.53-144, dated April 27, 1998:

(i) Paragraph 1.D.(1)(a): Inspect prior to the accumulation of 12,000 total flight cycles, or within 1,000 flight cycles after November 10, 1998 (the effective date of AD 98-21-06, amendment 39-10814), whichever occurs later.

(ii) Paragraph 1.D.(1)(b): Inspect prior to the accumulation of 16,000 total flight cycles, or within 1,200 flight cycles after November 10, 1998, whichever occurs later.

(iii) Paragraph 1.D.(1)(c): Inspect prior to the accumulation of 13,500 total flight cycles, or within 1,000 flight cycles after November 10, 1998, whichever occurs later.

(iv) Paragraph 1.D.(1)(d): Inspect prior to the accumulation of 22,000 total flight cycles, or within 1,400 flight cycles after November 10, 1998, whichever occurs later.

(2) For airplanes in the applicable configuration specified in Table 1 of Service Bulletin SB.53-144, Revision 1, dated May 21, 1999:

(i) For Model BAe 146-100 airplanes on which Modification HCM00020P has not been accomplished: Inspect prior to the accumulation of 11,600 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later.

(ii) For Model BAe 146-100 airplanes on which Modification HCM00020P has been accomplished: Inspect prior to the accumulation of 14,500 total flight cycles, or within 1,200 flight cycles after the effective date of this AD, whichever occurs later.

(iii) For Model BAe 146-200 airplanes on which Modification HCM00021J has not been accomplished: Inspect prior to the accumulation of 12,600 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later.

(iv) For Model BAe 146-200 airplanes on which Modification HCM00021J has been accomplished: Inspect prior to the accumulation of 11,600 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later.

(v) For Model BAe 146-300 airplanes on which Modification HCM01000B has not been accomplished: Inspect prior to the accumulation of 17,200 total flight cycles, or within 1,400 flight cycles after the effective date of this AD, whichever occurs later.

(b) Repeat the inspections required by paragraph (a) of this AD at the intervals defined in Significant Structural Item (SSI) Task No. 53-20-160 as detailed in Section 6 of the BAe 146 Maintenance Review Board Report, Revision 5, dated November 1998.

Corrective Action
(c) If any cracking is detected during any inspection required by paragraph (a) or (b) of this AD, 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 (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
(d) An alternativemethod 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 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
(e) 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
(f) The inspections shall be done in accordance with British Aerospace Service Bulletin SB.53-144, dated April 27, 1998, or British Aerospace Service Bulletin SB.53-144, Revision 1, May 21, 1999. Revision 1 of British Aerospace Service Bulletin 53-144 contains the following list of effective pages:

Page Number
Revision Level Shown on Page
Date Shown on Page
1-3, 7
1
May 21, 1999
4-6, 8-10
Original
April 27, 1998

(1) The incorporation by reference of British Aerospace Service Bulletin SB.53-144, Revision 1, dated May 21, 1999, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of British Aerospace Service Bulletin SB.53-144, dated April 27, 1998, was approved previously by the Director of the Federal Register as of November 10, 1998 (63 FR 53550, October 6, 1998).

(3) 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 ofthe Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 5: The subject of this AD is addressed in British airworthiness directive 005-04-98.

(g) This amendment becomes effective on April 24, 2000.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 98-21-06, amendment 39-10814 (63 FR 53550, October 6, 1998), which is applicable to certain British Aerospace Model BAe 146-100A, -200A, and -300A series airplanes, was published in the Federal Register on October 14, 1999 (64 FR 55636). The action proposed to require either a one-time non-destructive test (NDT) inspection or a detailed visual inspection for cracking of the fuselage skin in the vicinity of frame 29 between stringers 12 and 13, and repair, if necessary. The action also proposed to require that the current thresholds for these inspections be reduced and that repetitive inspections be performed.

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 Cite Revision 1 of Service Bulletin
One commenter,the manufacturer, states that, although paragraph (a) of the proposed AD contains the statement ". . . at the earlier of the applicable times specified in paragraphs (a)(1) and (a)(2). . . ," the commenter considers the paragraph's structure to be confusing. [Paragraphs (a)(1) and (a)(2) require compliance times as specified in British Aerospace Service Bulletin SB.53-144, dated April 27, 1998, and Revision 1, dated May 21, 1999, respectively]. The commenter requests that the main text of the proposed rule be revised to cite only Revision 1 of Service Bulletin SB.53-144 and its associated inspection periods, which are reduced from those specified in the original issue of the service bulletin. The commenter states that it has monitored results of inspections and has conducted metallurgical analysis on samples. From this effort, it has concluded that any uninspected airplanes should be inspected at the reduced compliance times specified in the later revision of the service bulletin.The FAA acknowledges that clarification of the AD may be helpful. However, the FAA does not concur with the request to include only those compliance times recommended in Revision 1 of Service Bulletin SB.53-144. Omitting compliance thresholds of an existing AD could result in the inadvertent extension of the compliance time for certain airplanes in a superseding AD.

If the compliance thresholds of the existing AD are not restated in the new AD, such that only the compliance times of the new AD are required, the new grace period can result in additional time allowed before the inspection must be accomplished. Therefore, when an AD is superseded specifically to reduce a compliance threshold, such an inadvertent extension of the compliance threshold would be contrary to the intent of requiring accomplishment of the existing requirements within an earlier timeframe.

In this case, the FAA's intent was to ensure that operators accomplish the inspection at the earliest timerequired by either the existing AD or this superseding AD. Consequently, this AD includes both the thresholds required by AD 98-21-06 and the reduced thresholds recommended in the service bulletin. An airplane subject to the requirements of the existing AD, and due to be inspected per the requirements of the existing AD, should still be inspected if the compliance time in the existing AD is earlier than that specified in the new AD.

Reference to Original Service Bulletin
The same commenter, in relation to the previous comment, suggests that the proposed AD be revised to reference the original issue of the service bulletin in a note to the AD. The commenter states that the note could identify that although the compliance times recommended in Revision 1 of the service bulletin are reduced, the inspection remains the same and, if the inspection has already been conducted, further inspections should continue in accordance with the Maintenance Review Board (MRB).

The FAA doesnot concur. Since "NOTE 2" of the AD already states that the actions defined in the original issue and Revision 1 of the service bulletin are identical, the FAA does not consider it necessary to add further information in regard to Service Bulletin SB.53-144. Additionally, since paragraph (b) of the AD already requires repetitive inspections as specified in a certain task of the MRB, there is no need to state that further inspections should continue in accordance with the MRB. No change to the AD is necessary.

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 as proposed.

Cost Impact
The FAA estimates that 23 airplanes of U.S. registry will be affected by this AD.

For operators that elect to accomplish the visual inspection rather than the NDT inspection, it will take approximately 6 work hours per airplane to accomplish it, at anaverage labor rate of $60 per work hour. Based on these figures, the cost impact of the visual inspection on U.S. operators is estimated to be $360 per airplane, per inspection cycle.

For operators that elect to accomplish the NDT inspection rather than the visual inspection, it will take approximately 8 work hours per airplane to accomplish it, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the NDT inspection on U.S. operators is estimated to be $480 per airplane, per inspection cycle.

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 have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of powerand 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 removing amendment 39-10814 (63 FR 53550, October 6, 1998), and by adding a new airworthiness directive (AD), amendment 39-11637, to read as follows: