Airworthiness directives: McDonnell Douglas,

[Federal Register: September 17, 1998 (Volume 63, Number 180)]

[Proposed Rules]

[Page 49679-49681]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr17se98-15]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-227-AD]

RIN 2120-AA64

Airworthiness Directives; McDonnell Douglas Model MD-11 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 series airplanes. This proposal would require inspections to detect attachment failures of the 12 attachments located on the No. 4 banjo fitting/pylon carry-through cap, and to detect cracking of the forward and aft flanges and bolt holes of the No. 4 banjo fitting; repair, if necessary; and replacement of the 12 attachments with new or serviceable parts. Such replacement would terminate the repetitive inspections. This proposal is prompted by a report indicating that attachment bolts on the forward and aft flanges of the No. 4 banjo fitting and the pylon carry-through cap failed due to fatigue cracking. The actions specified by the proposed AD are intended to prevent such cracking, which could result in reduced controllability of the airplane during flight and ground operations.

DATES: Comments must be received by November 2, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 96-NM-227-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 The Boeing Company, Douglas Products Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Department C1-L51 (2-60). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: John L. Cecil, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (562) 627-5229; fax (562) 627- 5210.

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 filedin the Rules Docket.

[[Page 49680]]

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-227-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-114, Attention: Rules Docket No. 96-NM-227-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports indicating that attachment bolts on the forward and aft flanges of the No. 4 banjo fitting and the pylon carry-through cap had failed on McDonnell Douglas Model MD-11 series airplanes. Investigation revealed that the steel attachment bolts had failed due to fatigue cracking. In addition, another report indicated that a 20-mm long crack in the forward flange of the No. 4 banjo fitting of the lower vertical stabilizer also had been detected. That airplane had accumulated 4,949 flight cycles and had logged 24,282 flight hours.

Fatigue cracking of the attachment bolts of the No. 4 banjo fittings, if not detected and corrected in a timely manner, could cause cracking of the flanges; such cracking, if not prevented, could result in reduced controllability of the airplane during flight and ground operations.

Explanation of Relevant Service Information

The FAA has reviewed and approved McDonnell Douglas MD-11 Service Bulletin 55-13, dated December 22, 1992, and Revision 1, dated December 17, 1993; and McDonnell Douglas Service Bulletin MD-11-55-013, Revision 02, dated October 28, 1996, and Revision 03, dated May 15, 1998; which are described as follows:

‹bullet› The original issue of the service bulletin describes procedures for replacement of the 12 attachment bolts located on the No. 4 banjo fitting/pylon carry-through cap with improved attachment bolts. These improved bolts are made from a higher strength and more corrosion resistant material. Replacement of the existing bolts with the improved bolts will minimize the possibility of attachment failures.

‹bullet› Revision 1 of the service bulletin adds an eddy current inspection to detect cracking of both the forward and aft flanges and of the bolt holes of the No. 4 banjo fitting, and replacement of the attachment bolts with a new or serviceable attachment bolts, if necessary. Revision 1 also adds airplanes to the effectivity of the original issue of the service bulletin.

‹bullet› Revision 02 of the service bulletin adds procedures for repetitive visual inspections to detect any discrepancies of the 12 attachments bolts located on the No. 4 banjo fitting/pylon carry- through cap, and repair, if necessary.

‹bullet› Revision 03 of the service bulletin specifies revised part numbers of second oversize Hi-Lok attachments. Revision 03 also specifies certain conditions for which additional work may or may not be necessary.

Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

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 require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletin

Operators should note that the service bulletin specifies that the manufacturer may be contacted if holes require enlargement beyond certain specifications, or for an evaluation for deferment of certain repairs. However, this proposal would require disposition of those conditions to be accomplished in accordance with a method approved by the FAA.

Cost Impact

There are approximately 82 airplanes of the affected design in the worldwide fleet. The FAA estimates that 31 airplanes of U.S. registry would be affected by this proposed AD.

The FAA estimates that it would take approximately 1 work hour per airplane to accomplish the proposed external visual inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $1,860, or $60 per airplane, per inspection cycle.

The FAA estimates that it would take approximately 2 work hours per airplane to accomplish the proposed eddy current inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $3,720, or $120 per airplane.

The FAA estimates that it would take approximately 6 work hours per airplane to accomplish the proposed replacement, and that the average labor rate is $60 per work hour. Required parts would cost approximately $250 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $18,910, or $610 per airplane.

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:

   [[Page 49681]]

   Authority: 49 U.S.C. 106(g), 40113, 44701.

   Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

   McDonnell Douglas: Docket 96-NM-227-AD.

   Applicability: Model MD-11 series airplanes; as listed in McDonnell Douglas Service Bulletin MD11-55-013, Revision 03, dated May 15, 1998; 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 (e) 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 failure of the attachment bolts on the forward and aft flanges of the No. 4 banjo fitting and the pylon carry-through cap due to fatigue cracking, and consequent reduced controllability of the airplane during flight and ground operation, accomplish the following:

   (a) Within 1,500 landings after the effective date of this AD, perform an external visual inspection for attachment failures of the 12 attachments located on the No. 4 banjo fitting/pylon carry- through cap, in accordance with McDonnell Douglas Service Bulletin MD11-55-013, Revision 02, dated October 28, 1996; or Revision 03, dated May 15, 1998.

   (1) If no failed attachment is found, repeat the external visual inspection thereafter at intervals not to exceed 1,500 landings until the terminating action specified in paragraph (b) of this AD is accomplished.

   (2) If any failed attachment is found, prior to further flight, accomplish the actions specified in paragraph (b) of this AD.

   (b) Except as provided by paragraph (c) of this AD: Within 5 years after the effective date of this AD, perform an eddy inspection to detect cracking of the forward and aft flanges and bolt holes of the No. 4 banjo fitting, in accordance with McDonnell Douglas MD-11 Service Bulletin 55-13, Revision 1, dated December 17, 1993; or McDonnell Douglas Service Bulletin MD11-55-013, Revision 02, dated October 28, 1996; or McDonnell Douglas Service Bulletin MD11-55-013, Revision 03, dated May 15, 1998.

   (1) If no cracking is found, within 5 years after the effective date of this AD, replace the 12 attachments located on the No. 4 banjo fitting/pylon carry-through cap with new or serviceable attachments in accordance with Revision 03 of the service bulletin. Such replacement constitutes terminating action for the repetitive inspections required by paragraph (a) of this AD.

   (2) If any cracking is found, prior to further flight, repair the fitting, and replace the 12 attachments located on the No. 4 banjo fitting/pylon carry-through cap with new or serviceable attachments in accordance with Revision 03 of the service bulletin. Such replacement constitutes terminating for the repetitive inspections required by paragraph (a) of this AD.

   (c) For airplanes on which McDonnell Douglas MD-11 Service Bulletin 55-13, dated December 22, 1992, has been accomplished, and on which no failed attachment was found during the inspection required by paragraph (a) of this AD: The eddy current bolt hole inspection specified in paragraph (b) of this AD is not required provided that all 12 attachments have been replaced in accordance with the original issue of the service bulletin.

   (d) If the service bulletin specifies that the manufacturer may be contacted for disposition of enlargement of holes beyond the specifications of the service bulletin, or for an evaluation for deferment of repairs: Those conditions shall be addressed in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

   (e) 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, Los Angeles ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

   Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

   (f) 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 September 10, 1998. Dorenda D. Baker, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 98-24869Filed9-16-98; 8:45 am]

   BILLING CODE 4910-13-U