## 69179 Federal Register /Vol. 63, No. 241 /Wednesday, December 16, 1998/Rules and Regulations

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95–NM–275–AD; Amendment 39–10942; AD 98–26–01]

RIN 2120–AA64



### Airworthiness Directives; Airbus Model A310 Series Airplanes

AGENCY

### : Federal Aviation Administration, DOT.

ACTION 

### : Final rule.

SUMMARY

### : This amendment adopts a new airworthiness directive (AD), applicable to all Airbus Model A310 series airplanes, that requires various inspections to detect fatigue cracks at certain locations on the fuselage, horizontal stabilizer, and wings and tail, and repair or modification, if necessary;
and installation of doublers. This amendment also adds new inspections and reduces certain inspection intervals. This amendment is prompted by results of full-scale fatigue testing of a Model A310 series airplane, which revealed fatigue cracks at those locations. The actions specified by this AD are intended to prevent reduced structural integrity of the fuselage, horizontal stabilizer, and wings.

DATES

### : Effective January 20, 1999.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of January 20,
1999.

ADDRESSES

### : The service information referenced in this AD may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. This information may be
examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 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

### : Norman B. Martenson, Manager, International Branch, ANM–116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055–4056; telephone (425) 227–2110; fax (425) 227–1149.

SUPPLEMENTARY INFORMATION 

### : 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 Airbus Model A310 series airplanes was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on July 21, 1998 (63 FR 39045). That supplemental NPRM proposed to require various inspections to detect fatigue cracks at certain locations on the fuselage, horizontal stabilizer, and wings and tail, and repair or modification, if necessary; and
installation of doublers. That supplemental NPRM also proposed to add new inspections and reduce certain inspection intervals.

Comments

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

Support for the Proposal

One commenter supports the proposed rule.

Request to Withdraw AD

The ATA, on behalf of one of its members, questions the need for an AD, and requests a meeting with the FAA to develop an alternative that would provide a program more beneficial to cost and safety. The commenter indicates that, while manufacturers routinely solicit comments from affected operators for aging aircraft issues, nothing in the proposal suggests that its requirements have been well coordinated with operators before being advised of pending rulemaking.

Additionally, the commenter questions whether each of the 16 referenced service bulletins individually satisfies the requirement of part 39 (‘‘Airworthiness Directives’’) of the Federal Aviation Regulations (14 CFR part 39) that an unsafe condition exists. As an example, the commenter points out that, in describing the reason for Airbus Service Bulletin A310–53–2014,
Airbus states that the existence of a
‘‘crack does not affect aircraft safety. . . .’’

The FAA infers that the commenter requests the AD be withdrawn. The FAA does not concur with that request.
Each of the 16 service bulletins cited in the original Notice of Proposed Rulemaking (NPRM), as well as the 2
additional service bulletins included in this Supplemental NPRM, address fatigue cracking in the wing, fuselage, and empennage structure of the airplane. As specified in the Airbus Structural Repair Manual (SRM), the wing, fuselage, and empennage structure is primary structure that contributes significantly to carrying flight, ground, and pressurization loads.
As is the case with the structure of many commercial airplanes, failure of a single part is not likely to be catastrophic, and safe flight could continue for some time with any single part being cracked or broken. However, if the parts specified in the service bulletins cited in this AD are cracked or failed, the residual strength of the surrounding aircraft structure would be reduced; this could cause failure of structural members, or could initiate or accelerate cracking of other structural members. Such failure clearly poses an unsafe condition. Issuance of an AD (without further delay) is the appropriate vehicle by which unsafe conditions are corrected.

Request for Alternative to Issuance of
AD

One ATA member suggests that, as an alternative to issuance of an AD, operators’ maintenance programs could be revised or adjusted to accomplish the inspection requirements of the proposed AD in line with scheduled maintenance visits. The commenter states that the A310 Maintenance Planning Document (MPD), one of the primary documents used by operators, addresses all areas covered by the proposed AD. The commenter adds that coordinating revisions to the inspection intervals specified in the MPD and corresponding service bulletins is more appropriate than issuing an AD. The commenter believes that this alternative would be less costly, would provide better control of early detection of damage, and would provide a better level of safety. The commenter states that no operator has yet found damage in the proposed inspection areas; however, the commenter submits no data to support

its contention.

The FAA does not concur that revising the MPD is more appropriate than issuing an AD. Accomplishment of the requirements detailed in the service bulletins is considered necessary, since those documents provide detailed inspection information necessary to address the unsafe condition that may
not be contained in the MPD. Additionally, the FAA has determined that solely relying on a revision of the maintenance document will not provide the same level of safety, since this document is not mandatory and, in any event, could be subsequently revised or adjusted without FAA approval. No change to the final rule is necessary in this regard.

Clarification of Development of Compliance Thresholds

One commenter indicates that it will request a review of the applicable service bulletins by the manufacturer to assure that the stated compliance
thresholds have a sound technical basis.

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The commenter requests that the FAA
coordinate this review with Airbus so that the AD is consistent with any changes being considered by Airbus. The commenter adds that, if necessary, the comment period should be extended so that coordination among Airbus, affected operators, and the FAA can be accomplished.

Another commenter expresses concern that the initial inspection thresholds specified in the proposal do not coincide with test findings, and questions how the criteria were developed. For example, the commenter objects to one threshold specified in the proposal as 12,000 flight cycles (FC) (with repetitive intervals of 5,000 FC) when cracking was not detected until 90,000 FC. The commenter indicates that, given the inspection thresholds specified in the proposal, operators will be forced to ground aircraft for special inspection visits, which impacts revenue and other operational parameters. The commenter believesthat adjustments in operators’ FAAapproved maintenance programs to achieve the required inspections and to maintain a level of safety will enhance the effectiveness of such programs.

The FAA finds that clarification is necessary concerning development of the compliance times specified in this AD. The inspection thresholds are based on test data, and adjustment to the thresholds to correspond with operators’ various maintenance programs is not always possible. The relationship between the specified inspection
threshold and the test data is based on a number of variables. In the example identified by the commenter, the crack was detected after 90,000 FC, and an inspection threshold of 12,000 FC was established. This reduction in flight cycles from the time that the crack was detected during testing to the inspection threshold established, is necessary to account for variations in operational usage, crack initiation and growth, inspection techniques, and human operational error. Additionally, the nature of fatigue testing requires that a ‘‘scatter’’ factor be applied to the data.
This scatter factor accounts for the number of specimens tested, material property variations, geometry/ configuration variations, environmental effects, and loading variations.

Based on these factors, the FAA has determined that the inspection thresholds established by Airbus, and approved by the DGAC, are acceptable to maintain the operational safety of these airplanes. No change to this final rule is necessary. Directions of Cracking
One commenter, Airbus, requests that the FAA clarify the definitions of directions of cracking. Airbus references a sentence that appears in the preamble to the original NPRM, which reads as follows: ‘‘Operators should note that although the French AD specifies that the airplane may be operated for 500 landings prior to repair of any crack that extends rearward, paragraph (h)(2)(iii) of this proposed AD would require that such cracking be repaired prior to further flight.’’ Airbus states that the ‘‘forward’’ crack propagates in the direction of the skin edge, and upon reaching the skin edge, the crack will not grow further; therefore, Airbus concludes that repair can be deferred for 500 flights. Airbus states that a ‘‘rearward’’ crack would propagate in the direction of the front spar where the
skin thickness increases and crack propagation slows down; therefore, repair of such rearward cracking also can be deferred for 500 flights.

The FAA does not concur. It is the FAA’s policy to require repair of known cracks prior to further flight, except in
certain cases of unusual need. This policy is based on the fact that such damaged airplanes do not conform to the FAA-certificated type design and, therefore, are not airworthy until a properly approved repair is incorporated. Therefore, since the FAA is unaware of any unusual need for repair deferral in this case, it has determined that, due to the safety implications and consequences associated with such cracking, any subject wing skin that is found to be cracked must be repaired prior to further flight. No change to the final rule is necessary.

Request To Revise Cost Impact Information

The ATA, on behalf of one of its members, requests that the FAA revise the cost impact information presented in the proposed AD. The ATA believes that the actual cost for accomplishment of the proposed requirements is considerably greater than that specified in the proposed AD. One ATA member justifies this request by presenting its

own cost estimate.

The ATA adds that the ‘‘boilerplate’’ paragraph contained in the proposed AD that indicates why a full cost-benefit analysis has not been accomplished (or is needed) is ‘‘particularly offensive’’ to
those affected. One ATA member believes that the paragraph is contrary to all established procedures of a rulemaking process, and the decision to issue an AD is being based on inaccurate and/or limited data. The ATA concludes that for the FAA to state that the level of safety has been determined previously to be cost beneficial discourages the submittal of any meaningful comments concerning the cost impact of the proposed AD. The ATA states that when operators submit comments to a docket on the cost of AD compliance, those operators are doing so to support the contention that equally safe alternative measures should be considered.

The FAA does not concur that the cost impact information should be revised based on the commenter’s justification. (However, it should be noted that the cost impact information presented in this AD was revised in the supplemental NPRM to reflect updated information presented in the latest service bulletin revisions.)

The cost impact information represents the FAA’s best estimate as to the number of work hours that will be necessary to accomplish the requirements of the AD. The FAA arrived at this estimate using cost information obtained from the airframe manufacturer. The FAA recognizes that actual costs may vary depending upon the operation of each individual airline and the degree to which the airplane has been opened up for access for other maintenance or inspection actions.

The ‘‘boilerplate’’ paragraph referenced by the ATA and one of its members is included in especially expensive AD’s, not to discourage comments regarding cost, but simply to explain why the FAA does not prepare full cost-benefit analyses. Cost effectiveness of AD’s is always a primary issue for the FAA in the development of AD’s. The FAA routinely adopts compliance times and methods that are designed to minimize the cost impact on operators. Thus, the FAA’s approach is entirely consistent with Executive Order 12866 in that it complies fully with the philosophy and principles set forth in Section 1 of the
executive order. It should be noted that AD’s were explicitly exempted from the Office of Management and Budget (OMB) coordination process described
in Section 6 of Executive Order 12866. The explanation of why full cost-benefit analyses are not required for AD’s is consistent with this exemption.

As for the ATA’s conclusion that the FAA is discouraging meaningful comments concerning cost by previously determining the level of safety to be cost beneficial, the FAA has not stated that a cost-benefit analysis has already been accomplished for AD’s. Rather, the paragraph states that the purpose of the AD is to restore the level

## 69181 Federal Register /Vol. 63, No. 241 /Wednesday, December 16, 1998/Rules and Regulations

of safety to that which has already been determined to be cost-effective. Under these circumstances, as stated in the paragraph, a full cost-benefit analysis would be redundant and unnecessary. The purpose of AD’s is distinctly different from the purpose of most other FAA regulations, which is to improve the level of safety established by the existing regulations. Under these circumstances, it is appropriate to conduct a cost-benefit analysis to determine whether the improvement in safety is cost-effective.

The FAA does not discourage comments concerning costs; to the contrary, every AD includes a provision specifically requesting comments on the economic aspects of the AD. Given the volume of such comments from operators, there does not appear to be any misunderstanding on the part of most operators about the appropriateness of submitting such

comments.

Finally, concerning the ATA’s statement that operators submit comments concerning cost to support their contention that equally safe alternative measures should be considered, if a commenter proposes a less costly alternative that achieves an acceptable level of safety, the FAA may concur with the comment and revise the AD accordingly. On the other hand, if a commenter simply requests a change without justifying it or providing data to substantiate it, the FAA may not concur. However, every AD contains a provision allowing operators to comply with the AD using an alternative method of compliance (or extension of compliance time) approved by the FAA.

Explanation of Change Made to This
Final Rule

Paragraph (h) of the final rule has
been revised to cite Revision 2 of Airbus Service Bulletin A310–57–2002, dated January 4, 1996, as an additional source
of service information for accomplishment of the actions specified in that paragraph. Revision 2 contains
no substantive differences from Revision 1 of the service bulletin, which was cited as the appropriate source of service information in the supplemental

NPRM.

Conclusion

After careful review of the available data, including the change 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

The FAA estimates that 36 airplanes of U.S. registry will be affected by this AD. Approximate work hours to accomplish the required actions and costs for required parts are listed in the following table. The average labor rate is $60 per work hour.

A310 service bulletin No. Work hours Parts cost/airplane Cost/airplane No. of U.S. airplanes Number modified

53–2014

................................................................................ 78 $12,121 $16,801 7 5
53–2016

................................................................................ 317 14,282 33,302 12 5
53–2054

................................................................................ 11 N/A 660 8 0
53–2057

................................................................................ 12 N/A 720 13 0
53–2059

................................................................................ 13 N/A 780 17 0
53–2074

................................................................................ 232 N/A 13,920 17 0
55–2002

................................................................................ 715 34,100 77,000 7 6
55–2004

................................................................................ 16 N/A 960 11 0
57–2002 ................................................................................ 8 N/A 480 6 0
57–2006

................................................................................ 52 N/A 3,120 2 0
57–2032 ................................................................................ 5 N/A 300 6 0
57–2037 ................................................................................ 2 N/A 120 6 0
57–2039 ................................................................................ 3 N/A 180 15 0
57–2046

................................................................................ 172 N/A 10,320 33 0
57–2047

................................................................................ 82 N/A 4,920 24 0
57–2050

................................................................................ 24 N/A 1,440 20 0
57–2064 ................................................................................ 8 N/A 480 26 0
57–2038 ................................................................................ 6 N/A 360 0 0



### Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $1,845,591. However, the FAA has
been advised that a certain number of U.S.-registered airplanes already have
been modified in accordance with the requirements of this AD. (The numbers of U.S.-registered airplanes that have already been modified are listed under the heading, ‘‘Number Modified,’’ in the table above.) Therefore, the future economic cost impact of this rule on U.S. operators is now $1,133,076.

The FAA recognizes that the obligation to maintain aircraft in an airworthy condition is vital, but sometimes expensive. Because AD’s require specific actions to address specific unsafe conditions, they appear to impose costs that would not otherwise be borne by operators. However, because of the general obligation of operators to maintain aircraft in an airworthy condition, this appearance is deceptive. Attributing those costs solely to the issuance of this AD is unrealistic because, in the interest of maintaining safe aircraft, prudent operators would accomplish the required actions even if they were not required to do so by the AD.

A full cost-benefit analysis has not been accomplished for this AD. As a matter of law, in order to be airworthy, an aircraft must conform to its type design and be in a condition for safe operation. The type design is approved only after the FAA makes a determination that it complies with all applicable airworthiness requirements. In adopting and maintaining those requirements, the FAA has already made the determination that theyestablish a level of safety that is costbeneficial. When the FAA, as in this AD, makes a finding of an unsafe condition, this means that the original cost-beneficial level of safety is no longer being achieved and that the required actions are necessary to restore that level of safety. Because this level of safety has already been determined to be cost-beneficial, a full cost-benefit analysis for this AD would be redundant and unnecessary.

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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 responsibilities among 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 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:

98–26–01 Airbus Industrie: Amendment
39–10942. Docket 95–NM–275–AD. Applicability: All Model A310 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 (u) 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 reduced structural integrity of the fuselage, horizontal stabilizer, and wings, accomplish the following:

(a) For airplanes listed in Airbus Service Bulletin A310–53–2014, Revision 5, dated June 9, 1992, as revised by Service Bulletin Change Notices 5.A., dated September 29, 1992, and 5.B., dated February 5, 1996: Prior to the accumulation of 12,000 total flight cycles, or within 500 flight cycles after the effective date of this AD, whichever occurs later, perform an eddy current inspection to detect cracks on the fuselage center section doublers at frame 40, and install new doublers, in accordance with Airbus Service Bulletin A310–53–2014, Revision 5, dated June 9, 1992, as revised by Service Bulletin Change Notices 5.A., dated September 29, 1992, and 5.B., dated February 5, 1996. Except as provided by paragraph (t) of this AD, if any discrepancy is found, prior to further flight, perform follow-on corrective actions, as applicable, in accordance with the
service bulletin.

(b) For airplanes listed in Airbus Service Bulletin A310–53–2016, Revision 5, dated December 7, 1992: Prior to the accumulation of 12,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, perform a defectoscope or rototest inspection to detect cracks in the area of frame 47 and frame 54, and install new doublers, in accordance with Airbus Service Bulletin A310–53–2016, Revision 5, dated December 7, 1992. Except as provided by paragraph (t) of this AD, if any discrepancy is found, prior to further flight, perform follow-on corrective actions, as applicable, in accordance with the service
bulletin.

(c) For airplanes listed in Airbus Service Bulletin A310–53–2054, Revision 2, dated May 22, 1990: Prior to the accumulation of 12,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, and thereafter at intervals not to exceed 3,000 flight cycles, perform a visual inspection to detect cracks on frame 46 between the left- and right-hand sides of stringers 21 and 22 on the forward
and aft faces in accordance with Airbus Service Bulletin A310–53–2054, Revision 2, dated May 22, 1990. If any crack is found, prior to further flight, repair in accordance with Airbus Service Bulletin A310–53–2054, Revision 2, dated May 22, 1990.

(1) Accomplishment of the repair required by paragraph (c) of this AD, or modification of the reinforcement angle runout in
accordance with Airbus Service Bulletin A310–53–2019, Revision 2, dated May 22, 1990, terminates the repetitive inspection requirements of paragraph (c) of this AD.

(2) Accomplishment of paragraph (c) of this AD terminates the requirements of AD 91–13–01, amendment 39–7032.

(d) For airplanes listed in Airbus Service Bulletin A310–53–2057, Revision 1, dated April 30, 1992: Perform a visual inspection to detect cracks at the T-section connecting
frame 50A to the beam between the left- and right-hand sides of frames 50 and 51, in
accordance with Airbus Service Bulletin A310–53–2057, Revision 1, dated April 30, 1992. Perform the inspection at the time specified in paragraph (d)(1) or (d)(2) of this AD, as applicable. If any crack is found, prior to further flight, accomplish Airbus
Modifications No. 4853 and No. 5273 in
accordance with Airbus Service Bulletin A310–53–2057, Revision 1, dated April 30, 1992. Accomplishment of these modifications terminates the requirements of this paragraph.

(1) For the airplane having manufacturer’s serial number (MSN) 191: Prior to the accumulation of 24,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 6,000 flight cycles.

(2) For airplanes other than the airplane identified in paragraph (d)(1) of this AD: Prior to the accumulation of 12,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 6,000 flight cycles.

(e) For airplanes listed in Airbus Service Bulletin A310–53–2059, Revision 1, dated January 4, 1996: Perform a visual inspection
to detect cracks in the lower milled side panel at the lap joint with the upper side panel at frame 47 and stringer 22, left- and right-hand sides, in accordance with Airbus Service Bulletin A310–53–2059, Revision 1, dated January 4, 1996. Perform the inspection at the time specified in paragraph (e)(1) or (e)(2) of this AD, as applicable. Except as provided by paragraph (t) of this AD, if any crack is found, prior to further flight, repair
in accordance with the service bulletin. Thereafter, repeat the inspections at intervals not to exceed 9,000 flight cycles, or accomplish Airbus Modification 5997 (Airbus Service Bulletin A310–53–2058). Accomplishment of either the repair or
Airbus Modification 5997 constitutes terminating action for the repetitive inspections required by this paragraph.

(1) For Model A310–200 series airplanes, accomplish the inspection at the time specified in paragraph (e)(1)(i) or (e)(1)(ii) of this AD, as applicable.

(i) For airplanes that have accumulated less than 20,000 total flight cycles as of the
effective date of this AD: Prior to the accumulation of 18,000 total flight cycles, or within 2,000 flight cycles after the effective date of this AD, whichever occurs later.

(ii) For airplanes that have accumulated 20,000 or more total flight cycles as of the effective date of this AD: Within 1,000 flight cycles after the effective date of this AD.

(2) For Model A310–300 series airplanes, accomplish the inspection at the time specified in paragraph (e)(2)(i) or (e)(2)(ii) of this AD, as applicable.

(i) For airplanes that have accumulated less than 19,700 total flight cycles as of the
effective date of this AD: Prior to the accumulation of 18,000 total flight cycles, or within 1,700 flight cycles after the effective date of this AD, whichever occurs later.

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(ii) For airplanes that have accumulated 19,700 or more total flight cycles as of the effective date of this AD: Within 850 flight cycles after the effective date of this AD.

(f) For airplanes listed in Airbus Service Bulletin A310–55–2002, Revision 4, dated April 28, 1989: Prior to the accumulation of 12,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, perform an eddy current inspection to detect cracks on the upper integral part adjacent to the rear attach fittings on the horizontal stabilizer, and modify the horizontal stabilizer, in
accordance with Airbus Service Bulletin A310–55–2002, Revision 4, dated April 28, 1989. Except as provided by paragraph (t) of this AD, if any discrepancy is found, prior to further flight, perform follow-on corrective actions, as applicable, in accordance with the
service bulletin.

(g) For airplanes listed in Airbus Service Bulletin A310–55–2004, Revision 2, dated February 7, 1991: Perform a high frequency eddy current rototest inspection to detect cracks at specified fastener holes in the top skin chordwise splice along the contour of
the steel doubler between ribs 3 and 4 on the left- and right-hand center and side boxes on
the horizontal stabilizer in accordance with Airbus Service Bulletin A310–55–2004, Revision 2, dated February 7, 1991, at the time specified in paragraph (g)(1) or (g)(2) of this AD, as applicable. Except as provided by paragraph (t) of this AD, if any discrepancy is found, prior to further flight, perform follow-on corrective actions, as applicable, in
accordance with the service bulletin.

(1) For airplanes on which Airbus Modification A310–4933 (Airbus Service Bulletin A310–55–2002) was accomplished prior to the accumulation of 6,000 total flight cycles on the airplane; or for airplanes having MSN 311 through 414 inclusive, on which
Airbus Modification A310–4933 was accomplished during production: Prior to the accumulation of 18,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 12,000 flight cycles.

(2) For airplanes on which Airbus Modification A310–4933 (Airbus Service Bulletin A310–55–2002) was accomplished upon or after the accumulation of 6,000 total flight cycles: Prior to the accumulation of 12,000 flight cycles since the modification, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 12,000 flight cycles.

(h) For airplanes listed in Airbus Service Bulletin A310–57–2002, Revision 2, dated January 4, 1996: Prior to the accumulation of 12,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 3,000 flight cycles; perform a detailed visual inspection to detect cracks in the external surface of the wing lower skin around the landing access panel holes of the leading edge, in accordance with Airbus Service Bulletin A310–57–2002, Revision 1, dated July 2, 1992; or Revision 2, dated January 4, 1996. If any discrepancy is found, 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 Direction Generale de l’Aviation Civile (DGAC) (or its delegated agent). Accomplishment of Airbus Modification 5101 (Airbus Service Bulletin A310–57–2003) terminates the repetitive inspection requirements of paragraph (h) of
this AD.

(i) For airplanes listed in Airbus Service Bulletin A310–57–2006, Revision 3, dated May 2, 1996: Prior to the accumulation of 6,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 3,000 flight cycles; perform an eddy current inspection to detect cracks in the holes around the overwing refueling aperture at ribs 13–14, in accordance with Airbus Service Bulletin A310–57–2006, Revision 3, dated May 2, 1996. Except as provided by paragraph (t) of this AD, if any discrepancy is found, prior to further flight, perform follow-on corrective actions, as applicable, in accordance with the service bulletin. Accomplishment of Airbus Modification 5891H5128 (Airbus Service Bulletin A310–57–2020) terminates the repetitive inspection requirements of paragraph (i) of this AD.

(j) For airplanes listed in Airbus Service Bulletin A310–57–2032, Revision 3, dated January 4, 1996: Prior to the accumulation of 12,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 4,500 flight cycles; perform a detailed visual inspection to detect cracks around the bolts in the wing top skin upper surface of the front spar between rib 7 and rib 28, in accordance with Airbus Service Bulletin A310–57–2032, Revision 3, dated January 4, 1996. If any discrepancy is found, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM–116, or the DGAC (or its delegated agent). Accomplishment of Airbus Modification 5026H0878 (Airbus Service Bulletin A310– 57–2005) terminates the repetitive inspection requirements of paragraph (j) of this AD.

(k) For airplanes listed in Airbus Service Bulletin A310–57–2037, Revision 3, dated January 4, 1996: Prior to the accumulation of 12,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 3,000 flight cycles; perform a high frequency eddy current inspection to detect cracks around the attachment bolt heads for the shroud panel landing on the bottom skin aft of the rear spar, forward of access door 575CB/675CB, in
accordance with Airbus Service Bulletin A310–57–2037, Revision 3, dated January 4, 1996. If any discrepancy is found, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM–116, or the DGAC (or its delegated agent). Accomplishment of Airbus Modification 5106H0894 (Airbus Service Bulletin A310– 57–2004) terminates the repetitive inspection requirements of paragraph (k) of this AD.

(l) For airplanes listed in Airbus Service Bulletin A310–57–2039, dated September 24, 1990: Perform either an eddy current or visual inspection to detect cracks on the left and right vertical posts, numbers 1 through 5 inclusive, in the wing center box at frame 40/41, in accordance with Airbus Service Bulletin A310–57–2039, dated September 24, 1990. Perform the inspection at the time specified in paragraph (l)(1) or (l)(2) of this AD, as applicable. Except as provided by paragraph (t) of this AD, if any crack is found, prior to further flight, accomplish the modification specified in Airbus Service Bulletin A310–57–2041, dated September 24, 1990, in accordance with Airbus Service Bulletin A310–57–2039, dated September 24, 1990.

(1) For airplanes on which Airbus Modification 7541/S7973 (reference Airbus Service Bulletin A310–57–2041) has not been accomplished: Inspect prior to the accumulation of 21,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 4,200 flight cycles (for a visual inspection), or 7,500 flight cycles (for an eddy current inspection).

(2) For airplanes on which Airbus Modification 7541/S7973 (reference Airbus Service Bulletin A310–57–2041) has been accomplished: Inspect at the time specified in the graph contained in NOTE 1 of paragraph 1.A.(2) of Airbus Service Bulletin A310–57–2039, dated September 24, 1990, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 5,000 flight cycles (for a visual inspection), or 8,600 flight cycles (for an eddy current inspection).

(m) For Model A310–200 series airplanes
on which Airbus Modification 7925H1113 has not been accomplished: Prior to the accumulation of 12,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, perform an ultrasonic inspection to detect
cracks in certain bolt holes where the main landing gear forward pick-up fitting is attached to the rear spar, in accordance with Airbus Service Bulletin A310–57–2046, Revision 4, dated October 16, 1996 (including Appendix 1, Revision 3, dated October 17, 1995), as revised by Service Bulletin Change Notice 4A, dated October 16, 1996. Accomplishment of paragraph (m) of this AD terminates the requirements of AD 91–06–18, amendment 39–6940.

(1) If no crack is found, accomplish either paragraph (m)(1)(i) or (m)(1)(ii) of this AD in
accordance with the service bulletin at the time specified in that paragraph.

(i) Repeat the inspection of the bolt/stud
holes thereafter at intervals not to exceed 3,500 flight cycles. Or

(ii) Prior to further flight, accomplish Airbus Modification 7925H1113; and, prior to the accumulation of 18,000 flight cycles after accomplishment of Airbus Modification 7925H1113, perform the inspection required by paragraph (m) of this AD. Repeat the inspection thereafter at intervals not to exceed 11,600 flight cycles.

Note 2: Airbus Service Bulletin A310–57– 2046, Revision 4, dated October 16, 1996 (including Appendix 1, Revision 3, dated October 17, 1995), as revised by Service Bulletin Change Notice 4A, dated October 16,

## 69184 Federal Register /Vol. 63, No. 241 /Wednesday, December 16, 1998/Rules and Regulations

1996, references Airbus Service Bulletin A310–57–2049 and Repair Instruction R571–
49305 as additional sources of service information for accomplishment of Airbus
Modification 7925H1113.

(2) If any crack is found, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM–116, or the DGAC (or its delegated agent).

(n) For Model A310–300 series airplanes
on which Airbus Modification 7925H1113 has not been accomplished: Prior to the accumulation of 9,000 flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, perform an ultrasonic inspection to detect cracks in certain bolt holes where the main landing gear forward pick-up fitting is attached to the rear spar, in accordance with Airbus Service Bulletin A310–57–2046, Revision 4, dated October 16, 1996 (including Appendix 1, Revision 3, dated October 17, 1995), as revised by Service Bulletin Change Notice 4A, dated October 16, 1996. Accomplishment of paragraph (n) of this AD terminates the requirements of AD 91–06–18, amendment
39–6940.

(1) If no crack is found, accomplish either paragraph (n)(1)(i) or (n)(1)(ii) of this AD in
accordance with the service bulletin at the time specified in that paragraph.

(i) Repeat the inspection of the bolt/stud
holes thereafter at intervals not to exceed 3,100 flight cycles. Or

(ii) Prior to further flight, accomplish Airbus Modification 7925H1113; and, prior to the accumulation of 18,000 flight cycles after accomplishment of Airbus Modification 7925H1113, perform the inspection required by paragraph (n) of this AD. Repeat the inspection thereafter at intervals not to exceed 11,600 flight cycles.

Note 3: Airbus Service Bulletin A310–57– 2046, Revision 4, dated October 16, 1996 (including Appendix 1, Revision 3, dated October 17, 1995), as revised by Service Bulletin Change Notice 4A, dated October 16, 1996, references Airbus Service Bulletin A310–57–2049 and Repair Instruction R571–
49305 as additional sources of service information for accomplishment of Airbus
Modification 7925H1113.

(2) If any crack is found, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM–116, or the DGAC (or its delegated agent).

(o) For airplanes listed in Airbus Service Bulletin A310–57–2047, Revision 2, dated January 22, 1997: Perform a rotating probe inspection to detect cracks in the fastener holes on the left- and right-hand sides of the rear spar internal angle and tee fitting, in
accordance with Airbus Service Bulletin A310–57–2047, Revision 2, dated January 22, 1997, at the applicable time specified in NOTE 2 of paragraph 1.A.(2) of the service bulletin, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at the intervals specified in NOTE 2 of paragraph 1.A.(2) of the service bulletin. Except as provided by paragraph (t) of this AD, if any discrepancy is found, prior to further flight, perform follow-on corrective actions in accordance with the service bulletin.

(p) For airplanes listed in Airbus Service Bulletin A310–57–2050, dated April 23, 1990, as revised by Service Bulletin Change Notices 0.A., dated September 29, 1992, and 0.B., dated January 6, 1995: Perform a visual or rotating probe inspection to detect cracks in the drain holes on the lower skin panel in the center wing box between frames 42 and 46, in accordance with Airbus Service Bulletin A310–57–2050, dated April 23, 1990, as revised by Service Bulletin Change Notices 0.A., dated September 29, 1992, and 0.B., dated January 6, 1995, at the applicable time specified in NOTE 1 of paragraph 1.A.(2) of the service bulletin, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed those specified in NOTE 1 of paragraph 1.A.(2) of the service bulletin. Except as provided by paragraph (t) of this AD, if any discrepancy is found, prior to further flight, perform follow-on corrective
actions in accordance with the service bulletin. Accomplishment of Airbus Modification number 6130S6815 (Airbus Service Bulletin A310–57–2048), constitutes terminating action for the repetitive inspections required by paragraph (p) of this
AD.

(q) For airplanes listed in Airbus Service Bulletin A310–53–2074, Revision 1, dated February 20, 1995: Perform visual and eddy current inspections to detect damaged sealant, corrosion, and cracks in accordance with Airbus Service Bulletin A310–53–2074, Revision 1, dated February 20, 1995. Accomplish these requirements at the applicable time specified in Table 2 of paragraph 1.C.(4) of the service bulletin, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later; and
thereafter at intervals not to exceed those specified in Table 2 of paragraph 1.C.(4) of the service bulletin, as applicable. Except as provided by paragraph (t) of this AD, if any discrepancy is found, prior to further flight, perform follow-on corrective actions in
accordance with the service bulletin.

(r) For airplanes listed in Airbus Service Bulletin A310–57–2064, dated August 24, 1995: Perform an eddy current inspection to detect cracks of the upper corner angle fitting and the vertical tee fitting at left and right frame 40, in accordance with Airbus Service Bulletin A310–57–2064, dated August 24, 1995. Perform the inspection at the time specified in paragraph (r)(1) or (r)(2) of this AD, as applicable. Except as provided by paragraph (t) of this AD, if any crack is found, prior to further flight, perform
corrective actions in accordance with the
service bulletin. (1) For Model A310–200 series airplanes: Prior to the accumulation of 18,000 total flight cycles, or within 2,000 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 11,000 flight cycles.

(2) For Model A310–300 series airplanes: Prior to the accumulation of 18,000 total flight cycles, or within 1,700 flight cycles after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 7,700 flight cycles.

(s) For airplanes listed in Airbus Service Bulletin A310–57–2038, Revision 2, dated January 4, 1996: Prior to the accumulation of 12,000 total flight cycles, or within 1,500 flight cycles after the effective date of this AD, whichever occurs later, perform a high frequency eddy current (HFEC) or X-ray inspection to detect cracking of the stringer
runouts inboard and outboard of rib 14 at stringers 6, 7, 8, and 9, in accordance with Airbus Service Bulletin A310–57–2038, Revision 2, dated January 4, 1996. Thereafter, repeat the inspection at intervals not to exceed those specified in paragraph 1.B.(5) of the service bulletin, as applicable. If any crack is detected, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM– 116, or the DGAC (or its delegated agent).

(t) If any crack is found during any inspection required by this AD, and the applicable service bulletin specifies to contact Airbus for an appropriate action: Prior to further flight, repair in accordance with a method approved by either the Manager, International Branch, ANM–116, or the DGAC (or its delegated agent).

(u) 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.

(v) 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.

(w) Except for the repairs required in paragraphs (h), (j), (k), (m)(2), (n)(2), (s), and (t) of this AD, the actions shall be done in accordance with the following Airbus service bulletins and change notices, as applicable, which contain the specified list of effective

pages:

Service bulletin and change notices referenced and date Page No. shown on page Revision level shown
on page Date shown on page

A310–53–2014, Revision 5, June 9, 1992

....... 1–3, 21, 25 ....................................................... 5 ................................ June 9, 1992. 4–6, 14–16, 19, 20, 23, 26 ............................... 2 ................................ February 17, 1987.

## 69185 Federal Register /Vol. 63, No. 241 /Wednesday, December 16, 1998/Rules and Regulations

Service bulletin and change notices referenced and date Page No. shown on page Revision level shown
on page Date shown on page

7–10, 12, 13, 17, 18, 22, 24 ............................. 3 ................................ May 18, 1987. 11, 27, 28 ......................................................... 4 ................................ March 1, 1988.A310–53–2014, Change Notice 5.A., September, 29, 1992

. 1 ........................................................................ Original

...................... September 29, 1992.

A310–53–2014, Change Notice 5.B., February

5, 1996

. 1 ........................................................................ Original

...................... February 5, 1996.

A310–53–2016, Revision 5, December 7, 1992 1, 2, 8, 12, 13, 43 ............................................. 5 ................................ December 7, 1992. 3, 4, 6, 7, 9–11, 16–18, 21–34, 39–42, 45 ...... 3 ................................ April 22, 1987.
5 ........................................................................ 1 ................................ November 12, 1985. 14, 15, 19, 20, 35–38, 44 ................................. 4 ................................ November 17, 1987. A310–53–2054, Revision 2, May 22, 1990 ...... 1 ........................................................................ 2 ................................ May 22, 1990.
2 ........................................................................ 1 ................................ February 19, 1990.
3–13

.................................................................. Original

...................... January 16, 1990. A310–53–2057, Revision 1, April 30, 1992

...... 1, 2 .................................................................... 1 ................................ April 30, 1992.
3–9

.................................................................... Original

...................... February 26, 1991. A310–53–2059, Revision 1, January 4, 1996

.. 1–6 .................................................................... 1 ................................ January 4, 1996.
7–26

.................................................................. Original

...................... October 4, 1991. A310–55–2002, Revision 4, April 28, 1989

...... 1, 31, 32 ........................................................... 4 ................................ April 28, 1989. 2–30, 33–47 ...................................................... 3 ................................ August 10, 1988. A310–55–2004, Revision 2, February 7, 1991 1–4, 6–8 ............................................................ 2 ................................ February 7, 1991. 5, 9–17

.............................................................. Original

...................... September 6, 1988. A310–57–2002, Revision 1, July 2, 1992

........ 1–4 .................................................................... 1 ................................ July 2, 1992.
5–11

.................................................................. Original

...................... December 31, 1988. A310–57–2002, Revision 2, January 4, 1996

.. 1–14 .................................................................. 2 ................................ January 4, 1996. A310–57–2006, Revision 3, May 2, 1996

........ 1, 10 .................................................................. 3 ................................ May 2, 1996.
2 ........................................................................ 2 ................................ March 28, 1995. 3, 4, 5–7 ........................................................... 1 ................................ April 8, 1993. 8, 9

.................................................................... Original

...................... August 13, 1986. A310–57–2032, Revision 3, January 4, 1996

.. 1–12 .................................................................. 3 ................................ January 4, 1996. A310–57–2037, Revision 3, January 4, 1996

.. 1–10 .................................................................. 3 ................................ January 4, 1996. A310–57–2039, September 24, 1990

.............. 1–13

.................................................................. Original

...................... September 24, 1990.

A310–57–2046, Revision 4, October 16, 1996 1–14 .................................................................. 4 ................................ October 16, 1996. Appendix 1

1–6 .................................................................... 3 ................................ October 17, 1995. A310–57–2046, Change Notice 4A, October

16, 1996

. 1 ........................................................................ Original

...................... October 16, 1996.

A310–57–2047, Revision 2, 57–58 January

22, 1997

. 1, 4, 7–8, 13, 17–18, 57–58 ............................. 2 ................................ January 22, 1997.

2, 3, 5–6, 16, 37–39 ......................................... 1 ................................ January 4, 1996. 9–12, 14–15, 19–36, 40–56, 59–89

................. Original

...................... February 26, 1991. A310–57–2050, April 23, 1990

......................... 1–31

.................................................................. Original

...................... April 23, 1990.A310–57–2050, Change Notice O.A., September 29, 1992

. 1 ........................................................................ Original

...................... September 29, 1992.

A310–57–2050, Change Notice O.B., January

6, 1995

. 1–2

.................................................................... Original

...................... January 6, 1995.

A310–53–2074, Revision 1, February 20, 1995 1–71 .................................................................. 1 ................................ February 20, 1995. A310–57–2064, August 24, 1995

..................... 1–25

.................................................................. Original

...................... August 24, 1995. A310–57–2038, Revision 2, January 4, 1996

.. 1–6 .................................................................... 2 ................................ January 4, 1996.

7 ........................................................................ Original

...................... November 6, 1989.



### 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 airworthiness directive 92–106– 132(B)R4, dated June 5, 1996. 

### (x) This amendment becomes effective on January 20, 1999.

Issued in Renton, Washington, on December 8, 1998.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98–33105 Filed 12–15–98; 8:45 am]

BILLING CODE 4910–13–U 

### DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–NM–336–AD; Amendment 39–10945; AD 98–26–04]

RIN 2120–AA64



### Airworthiness Directives; Boeing Model 757 Series Airplanes

AGENCY

### : Federal Aviation Administration, DOT.

ACTION 

### : Final rule; request for

comments.