AD 99-16-02

This amendment supersedes an existing airworthiness directive (AD), applicable to certain British Aerospace Model BAC 1-11 200 and 400 series airplanes, that currently limits the number of operations at increased cabin pressure differential, and requires repetitive structural inspections for cracking of the fuselage, and repair or replacement of parts, if necessary. This amendment requires additional repetitive inspections for cracking of the fuselage. This amendment is prompted by the determination that airplanes operating at increased cabin pressure differential are more likely to develop fatigue cracking earlier in their service lives than those airplanes operating at normal cabin differential pressures. The actions specified by this AD are intended to detect and correct fatigue cracking of the airplane fuselage, which could result in reduced structural integrity of the airplane.

Final rule

99-16-02 BRITISH AEROSPACE AIRBUS LIMITED (Formerly British Aerospace Commercial Aircraft Limited, British Aerospace Aircraft Group): Amendment 39-11237. Docket 98-NM-47-AD. Issued July 22, 1999. Supersedes AD 89-18-10, Amendment 39-6310.
Applicability: Model BAC 1-11 200 and 400 series airplanes on which British Aerospace Modifications PM2840 and PM3187 have been accomplished; or on which British Aerospace Modification PM4886 has been accomplished; except for airplanes on which British Aerospace Modification PM5282 (cabin freight door) has been accomplished; and certificated in any category.

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 (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 detect and correct fatigue cracking of the airplane fuselage, which could result in reduced structural integrity of the airplane, accomplish the following: RESTATEMENT OF REQUIREMENTS OF AD 89-18-10:

(a) Except as provided by paragraph (c) of this AD: For airplanes modified for operation to a maximum of 7.75 pounds per square inch (psi) cabin pressure differential, as specified in British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 1, dated January 27, 1987, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD.

(1)At or prior to the accumulation of 55,000 total landings, or within 15 months after September 28, 1989 (the effective date of AD 89-18-10, amendment 39-6310), whichever occurs later, perform the inspections specified in paragraph 2.1 of the alert service bulletin. Thereafter, repeat the inspections in accordance with paragraph 2.1.1 of the alert service bulletin at intervals shown in Table AA of the alert service bulletin.

(2) At or prior to the accumulation of 60,000 total landings, or within 30 days after September 28, 1989, whichever occurs later, reduce the aircraft maximum cabin pressure differential to 7.5 psi by system modification, in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate.

(b) Except as provided by paragraph (d) of this AD: For airplanes modified for operation at cabin pressure differentials above 7.75 psi up to a maximum of 8.2 psi, as specified in British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 1, dated January 27, 1987, accomplish the requirements of paragraph (b)(1) or (b)(2) of this AD, as applicable. Subsequently, accomplish the requirements of paragraphs (b)(3) and(b)(4), or paragraphs (b)(5) and (b)(6) of this AD, as applicable.

(1) For airplanes originally manufactured for operation at cabin pressure differentials above 7.75 psi, at or prior to the accumulation of the number of landings shown for initial inspection in the "NE period" column of Table AA in the alert service bulletin, or within 15 months after September 28, 1989, whichever occurs later, perform inspections specified in paragraph 2.2.1 of the alert service bulletin and repeat the inspections as specified in paragraph 2.2.3 of the alert service bulletin at the intervals shown in Table AA of the alert service bulletin.

(2) For airplanes modified for operation at cabin pressure differential above 7.75 psi after the airplane entered service, at or prior to the accumulation of the number of landings shown for initial inspection in the "NE period" column [obtained using the inspection adjustment graph (page 6) of the alert service bulletin], in Table AA of the alert service bulletin, or within 15 months after September 28, 1989, whichever occurs later, perform initial inspections specified in paragraph 2.2.2 of the alert service bulletin. Thereafter, repeat the inspections as specified in paragraph 2.2.3 of the alert service bulletin, at intervals shown in Table AA of the alert service bulletin.

(3) At or prior to the accumulation of 55,000 total landings, or within 30 days after September 28, 1989, whichever occurs later, reduce the aircraft cabin maximum operating pressure differential to 7.5 or 7.75 psi by modification as specified in paragraph 2.2.4 of the alert service bulletin, in accordance with a method approved by the Manager, International Branch, ANM-116.

(4) For airplanes which have had the cabin pressure differential reduced from 8.2 psi to 7.75 psi as specified in paragraph 2.2.6 of the alert service bulletin, perform repetitive inspections at the intervals specified in the "N.E. period" column in Table AA of the alert service bulletin.

(5) At or prior to the accumulation of 60,000 total landings, or within 30 days after September 28, 1989, whichever occurs later, the airplane cabin maximum operating pressure differential must be reduced to 7.5 psi by modification as specified in paragraph 2.2.7 of the alert service bulletin, in accordance with a method approved by the Manager, International Branch, ANM-116.

(6) For airplanes modified for 8.2 psi maximum cabin operating pressure differential and operated for a period in excess of any Table AA inspection threshold in the alert service bulletin, perform one additional inspection at or prior to the Table AA "N.E. period" column repeat interval after limiting operation to 7.5 psi, as specified in paragraph 2.2.5 of the alert service bulletin. NEW REQUIREMENTS OF THIS AD: New Initial and Repetitive Inspections

(c) For airplanes modified for operation to a maximum of 7.75 pounds per square inch (psi) cabin pressure differential, as specified in British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 2, dated April 27, 1995: Prior to the accumulation of the number of landings specified in Table AA of the alert service bulletin, or within 3 months after the effective date of this AD, whichever occurs later, perform the inspections specified in paragraph 2.1 of the alert service bulletin. Thereafter, repeat the inspections in accordance with paragraph 2.1.1 of the alert service bulletin at the intervals shown in Table AA of the alert service bulletin. Accomplishment of the inspections required by this paragraph terminates the repetitive inspections required by paragraph (a)(1) of this AD.

NOTE 2: Paragraph (a)(1) of this AD restates the requirement for an initial and repetitive inspections contained in paragraph A.1. ofAD 89-18-10. Therefore, for operators who have previously accomplished at least the initial inspection in accordance with AD 89-18-10, paragraph (c) of this AD requires that the next scheduled inspection be performed within the repetitive inspection interval specified in Table AA of Issue 2 of the alert service bulletin, after the last inspection performed in accordance with paragraph A.1. of AD 89-18-10.

(d) For airplanes modified for operation at cabin pressure differentials above 7.75 psi up to a maximum of 8.2 psi, as specified in British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 2, dated April 27, 1995: Prior to the accumulation of the number of landings specified in Table AA of the alert service bulletin, or within 3 months after the effective date of this AD, whichever occurs later, perform the inspections specified in paragraph 2.2.1 of the alert service bulletin. Thereafter, repeat the inspections in accordance with paragraph 2.2.3 of the alert service bulletin at the intervals shown in Table AA of the alert service bulletin. Accomplishment of the inspections required by this paragraph terminates the repetitive inspections required by paragraph (b)(1), (b)(2) or (b)(4) of this AD, as applicable.

NOTE 3: Paragraph (b)(1) of this AD restates the requirement for an initial and repetitive inspections contained in paragraph B.1. of AD 89-18-10. Therefore, for operators who have previously accomplished at least the initial inspection in accordance with AD 89-18-10, paragraph (d) of this AD requires that the next scheduled inspection be performed within the repetitive inspection interval specified in Table AA of Issue 2 of the alert service bulletin, after the last inspection performed in accordance with paragraph B.1. of AD 89-18-10. Corrective Actions

(e) If any defect is found during any inspection required by this AD, prior to further flight, accomplish paragraph (e)(1), (e)(2), or (e)(3) of this AD, as applicable.

(1) Replace the defective part with a serviceable part of the same part number in accordance with the Structural Repair Manual; or

(2) For damage within the limits specified in the BAC 1-11 Structural Repair Manual, repair in accordance with the Structural Repair Manual; or

(3) Repair in accordance with 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.

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

(g) 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

(h) Except as provided by paragraphs (a)(2), (b)(3), (b)(5), and (e) of this AD, the actions shall be done in accordance with British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 1, dated January 27, 1987, and British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 2, dated April 27, 1995. 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, Service Support, Airbus Limited, P.O. Box 77, Bristol BS99 7AR, England. 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.

(i) This amendment becomes effective on September 7, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 89-18-10, amendment 39-6310 (54 FR 34768, August 22, 1989), which is applicable to certain British Aerospace Model BAC 1-11 200 and 400 series airplanes, was published in the Federal Register on January 5, 1999 (64 FR 435). The action proposed to continue to limit the number of operations at increased cabin pressure differential, and to require repetitive structural inspections for cracking of the fuselage, and repair or replacement of parts, if necessary. The action also proposed to require additional repetitive inspections for cracking of the fuselage.

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. Service Bulletin Reference

One commenter, the manufacturer, states that paragraph (b)(5) of the proposed AD refers toparagraph 2.2.7 of British Aerospace Alert Service Bulletin 53-A-PM5922, but this service bulletin does not contain a paragraph 2.2.7. The commenter suggests that the correct paragraph reference should be to paragraph 2.1.2 of the alert service bulletin. The FAA concurs that Issue 2 of the alert service bulletin, dated April 27, 1995, does not contain a paragraph 2.2.7. However, paragraph (b) of the AD is an existing requirement retained from AD 89-18-10, which requires accomplishment of certain actions in accordance with Issue 1 of the alert service bulletin, dated January 27, 1987. Since Issue 1 of the alert service bulletin contains a paragraph 2.2.7, the reference is correct, and no change is made to the final rule in this regard. However, to allow better identification of the retained and the new requirements of this AD, subject headers have been added to the final rule.

Compliance Time
One commenter notes that it supports the proposed 3-month compliance time for initiation of the additional inspections. The commenter also states that, in light of the urgency of the unsafe condition, it would like the compliance time to be shorter but understands the maintenance, scheduling, and logistics involved with accomplishing the actions specified. The FAA infers that the commenter does not object to the proposed compliance time; no change is made to the final rule. 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 change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
There are approximately 42 series airplanes of U.S. registry that will be affected by this AD.

The actions that are currently required by AD 89-18-10 take approximately 67 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the previously required actions on U.S. operators is estimated to be $168,840, or $4,020 per airplane.

The new inspections that are required by this AD will take approximately 29 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the new requirements of this AD on U.S. operators is estimated to be $73,080, or $1,740 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 substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilitiesamong the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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 ofthe 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 39-6310 (54 FR 34768, August 22, 1989), and by adding a new airworthiness directive (AD), amendment 39-11237, to read as follows: