AD 97-8125

[Federal Register Volume 62, Number 62 (Tuesday, April 1, 1997)] [Proposed Rules] [Pages 15429-15431] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 97-8125]

======================================================================== Proposed Rules Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. ========================================================================

Federal Register / Vol. 62, No. 62 / Tuesday, April 1, 1997 / Proposed Rules

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-257-AD] RIN 2120-AA64

Airworthiness Directives; Lockheed Model L-1011-385 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Lockheed Model L-1011- 385 series airplanes, that currently requires various types of inspections to detect fatigue cracking of certain areas of the rear spar caps, web, skin, and certain fastener holes; and repair or modification, if necessary. This action would reduce the repetitive inspection interval for all of the currently required inspections, except for the x-ray inspections. It also would revise the terminating modification provision for some airplanes. This proposal is prompted by reports of cracks found during the currently-required inspections, which had progressed to lengths greater than predicted. The actions specified by the proposed AD are intended to ensure that fatigue cracking is detected and corrected in a timely manner before it can lead to rupture of the rear spar, extensive damage to the wing, and spillage of fuel.

DATES: Comments must be received by May 9, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 96-NM-257-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from Lockheed Aeronautical Systems Support Company, Field Support Department, Dept. 693, Zone 0755, 2251 Lake Park Drive, Smyrna, Georgia 30080. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Thomas Peters, Aerospace Engineer, Systems and Flight Test Branch, ACE-116A, FAA, Atlanta Aircraft Certification Office, Small Airplane Directorate, Campus Building, 1701 Columbia Avenue, Suite 2-160, College Park, Georgia 30337-2748; telephone (404) 305-7367; fax (404) 305-7348.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 96-NM-257-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 96-NM-257-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On March 28, 1996, the FAA issued AD 96-07-13, amendment 39-9563 (61 FR 16379, April 15, 1996), applicable to all Lockheed Model L-1011- 385 series airplanes. That AD requires repetitive visual, x-ray, eddy current, and ultrasonic inspections to detect fatigue cracking of certain areas of the rear spar caps, web, skin, and certain fastener holes; and repair or modification, if necessary. It also provides for modification of the rear spar upper and lower caps between Inner Wing Station (IWS) 228 and 346 as terminating action for the requirements of the AD. AD 96-07-13 was prompted by reports of fatigue cracking that occurred in these areas. The requirements of that AD are intended to ensure that fatigue cracking is detected and corrected in a timely manner. Such cracking, if not corrected, could lead to rupture of the rear spar and, consequently, result in extensive damage to the wing and spillage of fuel.

Actions Since Issuance of Previous Rule

Since the issuance of AD 96-07-13, the FAA has received reports indicating that fatigue cracks detected during inspections performed in accordance with that AD had progressed to lengths greater than predicted. One finding indicated that a crack apparently had grown substantially during the repetitive inspection period. These new data indicate that, in order to detect and correct the subject fatigue cracking before it can progress to critical lengths, the currently required inspections must be performed more frequently. Additionally, the manufacturer has notified the FAA that the modification of the rear spar upper and lower caps on Model L-1011-385- 3 airplanes, which was described in Part I of Lockheed Service Bulletin 093-57-203, Revision 4, dated March 27, 1995, has been superseded by a web replacement that is described in Lockheed Service Bulletin 093-57- 215.

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Explanation of Relevant Service Information

The FAA has reviewed and approved Lockheed Service Bulletin 093-57- 203, Revision 5, dated April 22, 1996, which describes procedures for conducting repetitive inspections to detect fatigue cracking in the inboard web periphery from IWS 346 to IWS 228. It recommends that the inspections be repeated at shorter intervals than those recommended in Revision 4 of this service bulletin (dated March 27, 1995). The shorter intervals will ensure that cracking is detected in a more timely manner. Additionally, Revision 5 does not contain procedures for the modification of the rear spar upper and lower caps for Model L-1011- 385-3 airplanes, which was contained in Revision 4. That modification has been revised, and the procedures for it are now contained in Lockheed L-1011 Service Bulletin 093-57-215, dated April 11, 1996.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would supersede AD 96-07-13. It would continue to require the same types of inspections to detect fatigue cracking of certain areas of the rear spar caps, web, skin, and certain fastener holes; and repair or modification, if necessary. However, except for the currently required x-ray inspections, these inspections would be required to be repeated at shorter intervals. These actions would be required to be accomplished in accordance with Revision 5 of Lockheed Service Bulletin 093-57-203, described previously. This new proposed AD would continue to provide for terminating action for the repetitive inspections, as was provided in AD 96-07-13. However, terminating action for Model L-1011-385-3 airplanes would be required to be accomplished in accordance with the procedures specified in Lockheed L-1011 Service Bulletin 093-57-215.

Cost Impact

There are approximately 236 Lockheed Model L-1011-385 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 118 airplanes of U.S. registry would be affected by this proposed AD. The inspections that are proposed in this AD action would take approximately 64 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. [This work hour estimate assumes that X-ray inspections are done of both upper and lower caps, and that the ultrasonic inspection indicates cracking in each of five bolt holes (per wing), thus requiring subsequent bolt hole eddy current inspections to confirm crack findings. The estimate includes inspections of both wings.] Based on these figures, the cost impact on U.S. operators of the proposed inspection requirements of this AD is estimated to be $453,120, or $3,840 per airplane, per inspection cycle. The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed 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 proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this proposed regulation (1) Is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing amendment 39-9563 (61 FR 16379, April 15, 1996), and by adding a new airworthiness directive (AD), to read as follows:

Lockheed: Docket 96-NM-257-AD. Supersedes AD 96-07-13, Amendment 39- 9563.

Applicability: All Model L-1011-385-1, L-1011-385-3, L-1011-385- 1-14, and L-1011-385-1-15 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 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 rupture of the rear spar due to the problems associated with fatigue cracking, which could result in extensive damage to the wing and fuel spillage, accomplish the following: Note 2: The inspections and follow-on actions described in Lockheed L-1011 Service Bulletin 093-57-203 include:

--repetitive X-ray (radiographic) inspections; --repetitive eddy current surface scan inspections; --bolt hole eddy current inspections at various locations; --repetitive ultrasonic inspections in conjunction with eddy current surface scan inspections (for certain airplanes); and --repetitive low frequency eddy current ring probe inspections.

(a) For airplanes on which the inspections and follow-on actions required by AD 96-07-13, amendment 39-9563, have been initiated prior to the effective date of this AD: At the times specified in Table I of Lockheed L-1011 Service Bulletin 093-57-203, Revision 4, dated March 27, 1995; or within 6 months after May 15, 1996 (the effective date of AD 96-07-13, amendment 39-9563), whichever occurs later: Perform initial inspections and various follow-on actions to detect cracking in the areas specified in, at the times indicated in, and in accordance with Lockheed L-1011 Service Bulletin 093-57- 203, Revision 4, dated March 27, 1995, or Revision 5, dated April 22, 1996.

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(1) If no cracking is found, repeat the repetitive inspections and follow-on actions in accordance with Table I of the Lockheed service bulletin. As of the effective date of this AD, these actions shall be repeated at the times specified only in accordance with Table 1 of Revision 5 of the Lockheed service bulletins. To avoid unnecessary grounding of airplanes that are currently being inspected in accordance with the schedule specified in Revision 4 of the Lockheed service bulletin, the next repeated action that is to be accomplished after the effective date of this AD shall be performed at the time specified in Table I of Revision 5 of the Lockheed service bulletin, or within 30 days after the effective date of this AD, whichever occurs later. (2) If any finding of cracking is confirmed, prior to further flight, accomplish paragraph (a)(2)(i), (a)(2)(ii), or (a)(2)(iii) of this AD. (i) Repair the cracked area in accordance with a method approved by the Manager, Atlanta Aircraft Certification Office (ACO), FAA, Small Airplane Directorate. Thereafter, perform the repetitive inspections and follow-on actions as specified in paragraph (a)(1) of this AD. (ii) Repair the rear spar upper and lower caps between IWS 228 and 346 in accordance with the Lockheed Model L-1011 Structural Repair Manual. Thereafter, perform the repetitive inspections and follow-on actions required by paragraph (a)(1) of this AD. Or (iii) Modify the rear spar upper and lower caps and web in accordance with the applicable Lockheed service bulletin listed in this paragraph, below. Accomplishment of the modification constitutes terminating action for the requirements of this AD.

--Lockheed L-1011 Service Bulletin 093-57-184, Revision 7, dated December 6, 1994, as amended by Change Notification 093-57-184, R7- CN1, dated August 22, 1995; or --Lockheed Service Bulletin 093-57-196, Revision 6, dated December 6, 1994, as amended by Change Notification 093-57-196, R6-CN1, dated August 22, 1995; or --Lockheed L-1011 Service Bulletin 093-57-215, dated April 11, 1996. Modification of Model L-1011-385-3 airplanes must be accomplished in accordance with this service bulletin.

Note 3: Accomplishment of the modification specified in paragraph (a)(2)(iii) of this AD prior to the effective date of this AD in accordance with the following Lockheed service bulletins, as applicable, is considered to be in compliance with this paragraph:

Lockheed L-1011 Service Bulletin 093-57-184, Revision 6, dated October 28, 1991 Lockheed L-1011 Service Bulletin 093-57-184, Revision 7, dated December 6, 1994 Lockheed L-1011 Service Bulletin 093-57-196, Revision 5, dated October 28, 1991 Lockheed L-1011 Service Bulletin 093-57-196, Revision 6, dated December 6, 1994

(b) For airplanes on which the inspections and follow-on actions required by AD 96-07-13, amendment 39-9563, have not been initiated prior to the effective date of this AD: At the times specified in Table I of Lockheed L-1011 Service Bulletin 093-57-203, Revision 5, dated April 22, 1996; or within 30 days after the effective date of this AD; whichever occurs later: Perform initial inspections and various follow-on actions to detect cracking in the areas specified in, at the times indicated in, and in accordance with Lockheed L- 1011 Service Bulletin 093-57-203, Revision 5, dated April 22, 1996. (1) If no cracking is found: Repeat the inspections and follow- on actions in accordance with the times specified in Table I of the Lockheed service bulletin. (2) If any finding of cracking is confirmed: Prior to further flight, accomplish either paragraph (b)(2)(i), (b)(2)(ii), or (b)(2)(iii) of this AD. (i) Repair the cracked area in accordance with a method approved by the Manager, Atlanta Aircraft Certification Office (ACO), FAA, Small Airplane Directorate. Thereafter, perform the repetitive inspections and follow-on actions at the times specified in Table 1 of the Lockheed service bulletin. Or (ii) Repair the rear spar upper and lower caps between IWS 228 and 346 in accordance with the Lockheed Model L-1011 Structural Repair Manual. Thereafter, perform the repetitive inspections and follow-on actions at the times specified in Table 1 of the Lockheed service bulletin. Or (iii) Modify the rear spar upper and lower caps and web in accordance with paragraph (a)(2)(iii) of this AD. (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, Atlanta ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO.

Note 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

(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.

Issued in Renton, Washington, on March 25, 1997. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 97-8125 Filed 3-31-97; 8:45 am] BILLING CODE 4910-13-U