03-20715. Airworthiness Directives; McDonnell Douglas Model DC-8-11, DC-8-12, DC-8-21, DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, DC-8-43, DC-8F-54, and DC-8F-55 Airplanes; and DC-8-50, DC-8-60, DC-8-60F, DC-8-70, and DC-8-70F 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 airplane models. For certain airplanes, this proposal would require a one-time test to determine the material of the upper inboard spar cap of the wing, or a one-time inspection to determine if the slant panel cap has been repaired previously. For most airplanes, this proposal also would require a one-time inspection for corrosion of the slant panel cap of the wing leading edge assembly, and follow-on actions. This action is necessary to prevent stress corrosion cracking in the forward tang of the upper inboard spar cap of the wing, which could result in structural damage to adjacent components of the wing and consequent reduced structural integrity of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by September 29, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-343-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-343-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT:

Jon Mowery, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

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 action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-343-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. 2001-NM-343-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports indicating that cracking has been found in the forward tang of the upper inboard spar cap of the wing on certain McDonnell Douglas Model DC-8-70 series airplanes. The cracking has been found on airplanes that have accumulated approximately 18,000 total flight hours. The cracking occurred between the fuselage and wing station Xfs=67.500 on the left and right sides of the airplane, and has been attributed to stress corrosion. This condition, if not corrected, could result in structural damage to adjacent components of the wing and consequent reduced structural integrity of the airplane.

Explanation of Relevant Service Information

The FAA has reviewed and approved McDonnell Douglas Service Bulletin DC8-57-072 R03, Revision 03, dated October 2, 1995. That service bulletin describes procedures for performing test or inspections between stations Xcw=69.500 and Xfs=67.500, and repairs or modifications if necessary, on three airplane groups, as follows:

• For airplanes in Group 1, the service bulletin describes procedures for a one-time eddy current conductivity test of the upper inboard spar cap of the wing to determine the type of material. For an upper inboard spar cap of certain material, the service bulletin specifies accomplishing a modification of the slant panel cap of the wing leading edge assembly per a figure in a certain chapter of the structural repair manual (SRM). For airplanes in Group 1, the service bulletin does not describe procedures for modification of the wing spar cap. (The procedures in the SRM involve performing a general visual inspection for corrosion, removing any evidence of corrosion, installing fillers, and installing an external rework doubler, as applicable.) For an upper inboard spar cap of certain other material, the service bulletin describes procedures for a visual inspection for corrosion or a previous repair of the slant panel cap of the wing leading edge assembly. The service bulletin describes procedures for a modification as a follow-on action for this inspection. That modification involves removing any corrosion, repairing the slant panel cap of the leading edge assembly or replacing it with a new slant panel cap, modifying the front spar stiffeners and upper spar cap, and installing doublers on the wing upper surface.
• For airplanes in Group 2, the service bulletin describes procedures identical to those for Group 1 airplanes, except that no conductivity test is necessary, and a previously installed repair must be removed before modifying the front spar stiffeners and upper spar cap.
• For airplanes in Group 3, the service bulletin describes procedures for a visual inspection for corrosion of the slant panel cap of the wing leading edge assembly, and a modification that involves modifying the front spar stiffeners, and replacing the slant panel cap with a new improved cap if necessary.

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

Explanation of Related AD

We have previously issued AD 90-16-05, amendment 39-6614 (55 FR 31818, August 6, 1990), which applies to McDonnell Douglas Model DC-8 series airplanes, as listed in McDonnell Douglas Report No. MDC K1579, Revision A, dated March 1, 1990. McDonnell Douglas Report No. MDC K1579, Revision A, specifies accomplishment of certain inspections and structural modifications in accordance with various service bulletins, including McDonnell Douglas Service Bulletin DC8-57-72, Revision 2, dated July 16, 1971; and McDonnell Douglas DC-8 Service Bulletin 57-34, Revision 3, dated December 29, 1970. Accomplishment of the actions in this proposed AD would constitute compliance with the inspections required by paragraph A. of AD 90-16-05, as it pertains to those service bulletins.

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.

Clarification of Inspection Type

The service bulletin identifies the inspection for corrosion or previous repair, as applicable, as a “visual inspection.” However, we find that the procedures described in the service bulletin constitute a detailed inspection. A definition of this type of inspection is included in Note 1 of this AD.

Differences Between Proposed AD and Service Information

As stated previously, McDonnell Douglas Service Bulletin DC8-57-072 R03, Revision 03, refers to a certain figure in a certain chapter of the SRM as a source for additional information for a follow-on modification of the slant panel cap. Where that referenced figure specifies to contact the manufacturer for appropriate action, this proposed AD would require the repair of those conditions to be accomplished per a method approved by the FAA, or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the FAA to make such findings.

Also, while McDonnell Douglas Service Bulletin DC8-57-072 R03, Revision 03, states that, for airplanes listed in Group 3 of the service bulletin, modification of the front spar stiffeners may be deferred until DC-8 Service Bulletin 57-30 is accomplished, this proposed AD would not allow such a deferral. We find that the proposed 4-year compliance time represents an appropriate interval of time for affected airplanes to continue to operate without compromising safety.

Changes to 14 CFR Part 39/Effect on the Proposed AD

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance (AMOCs). Because we have now included this material in part 39, only the office authorized to approve AMOCs is identified in each individual AD.

Change to Labor Rate Estimate

We have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Cost Impact

There are approximately 303 airplanes of the affected design in the worldwide fleet. The FAA estimates that 229 airplanes of U.S. registry would be affected by this proposed AD.

For airplanes in Group 1, the electrical conductivity test would take approximately 1 work hour per airplane, at the average labor rate of $65 per work hour. Based on these figures, the cost impact of this proposed inspection is estimated to be $65 per airplane.

For airplanes subject to the inspection for corrosion or previous repairs, as applicable, and the modification, these actions would take between 110 and 416 work hours per airplane, at the average labor rate of $65 per work hour. Required parts would cost between $4,554 and $19,687. Based on these figures, the cost impact of these proposed actions is estimated to be between $11,704 and $46,727 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 proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would not have a substantial direct effect 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, it is determined that this proposal would not have federalism implications under Executive Order 13132.

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.

§ 39.13

[Amended]

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

McDonnell Douglas: Docket 2001-NM-343-AD.

Applicability: Model DC-8-11, DC-8-12, DC-8-21, DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, DC-8-43, DC-8-51, DC-8-52, DC-8-53, DC-8-55, DC-8F-54, DC-8F-55, DC-8-61, DC-8-62, DC-8-63, DC-8-61F, DC-8-62F, DC-8-63F, DC-8-71, DC-8-72, DC-8-73, DC-8-71F, DC-8-72F, and DC-8-73F airplanes; certificated in any category; as listed in McDonnell Douglas Service Bulletin DC8-57-072 R03, Revision 03, dated October 2, 1995.

Compliance: Required as indicated, unless accomplished previously.

To prevent stress corrosion cracking in the forward tang of the upper inboard spar cap of the wing, which could result in structural damage to adjacent components of the wing and consequent reduced structural integrity of the airplane, accomplish the following:

Group 1 Airplanes: Inspection and Follow-On Actions

(a) For airplanes in Group 1 as defined by McDonnell Douglas Service Bulletin DC8-57-072 R03, Revision 03, dated October 2, 1995: Within 4 years after the effective date of this AD, perform a one-time eddy current conductivity test of the upper inboard spar cap of the wing to determine the type of material, per the Accomplishment Instructions of the service bulletin.

(1) If the test reveals that the upper inboard spar cap is made from 7075-T73 material (as defined in the service bulletin), before further flight, perform a detailed inspection for corrosion and modify the slant panel cap of the wing leading edge assembly per the figure and chapter of the structural repair manual (SRM) specified in the service bulletin, per the Accomplishment Instructions of the service bulletin. It is not necessary to modify the wing spar cap. The modification of the slant panel cap involves removing any evidence of corrosion, installing fillers, and installing an external rework doubler, as applicable. For conditions in which the referenced SRM figure specifies to contact the manufacturer for appropriate action: Before further flight, repair per a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Los Angeles ACO, to make such findings. For a repair method to be approved, the approval must specifically reference this AD.

Note 1:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(2) If the test reveals that the upper inboard spar cap is made from 7079-T6 material, before further flight, perform a detailed inspection to find corrosion or a previous repair of the slant panel cap of the wing leading edge assembly, and accomplish the modification specified in the service bulletin, per the Accomplishment Instructions of the service bulletin. The modification involves removing any corrosion and repairing the slant panel cap of the leading edge assembly, or replacing the slant panel cap with a new improved slant panel cap, as applicable; modifying the front spar stiffeners and upper spar cap; and installing doublers on the wing upper surface.

Group 2 Airplanes: Inspection and Modification

(b) For airplanes in Group 2 as defined by McDonnell Douglas Service Bulletin DC8-57-072 R03, Revision 03, dated October 2, 1995: Within 4 years after the effective date of this AD, perform a detailed inspection to find corrosion or a previous repair of the slant panel cap of the wing leading edge assembly, and accomplish the modification specified in the service bulletin, per the Accomplishment Instructions of the service bulletin. The modification involves removing any corrosion and repairing the slant panel cap of the leading edge assembly, or replacing it with a new improved slant panel cap, as applicable; removing any previously installed repair; modifying the front spar stiffeners and upper spar cap; and installing doublers on the wing upper surface.

Group 3 Airplanes: Inspection and Modification

(c) For airplanes in Group 3 as defined by McDonnell Douglas Service Bulletin DC8-57-072 R03, Revision 03, dated October 2, 1995: Within 4 years after the effective date of this AD, perform a detailed inspection to find corrosion of the slant panel cap of the wing leading edge assembly, and accomplish the modification specified in the service bulletin, per the Accomplishment Instructions of the service bulletin. The modification involves modifying the front spar stiffeners, and replacing the slant panel cap with a new improved cap, as applicable.

Note 2:

Although McDonnell Douglas Service Bulletin DC8-57-072 R03, Revision 03, states that, for airplanes listed in Group 3 of the service bulletin, modification of the front spar stiffeners may be deferred until DC-8 Service Bulletin 57-30 is accomplished, this AD does not allow such a deferral.

Certain Actions Constitute Compliance With AD 90-16-05

(d) Accomplishment of the action(s) required by this AD constitutes compliance with the inspections required by paragraph A. of AD 90-16-05, as it pertains to McDonnell Douglas Service Bulletin DC8-57-72, Revision 2, dated July 16, 1971; and McDonnell Douglas DC-8 Service Bulletin 57-34, Revision 3, dated December 29, 1970. Accomplishment of the actions required by this AD does not terminate the remaining requirements of AD 90-16-05 as it applies to other service bulletins; operators are required to continue to inspect and/or modify per the other service bulletins listed in that AD.

Alternative Methods of Compliance

(e)(1) In accordance with 14 CFR 39.19, the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, is authorized to approve alternative methods of compliance (AMOC) for this AD.

(2) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by a Boeing Company DER who has been authorized by the Manager, Los Angeles ACO, to make such findings.

Issued in Renton, Washington, on August 7, 2003.

Neil D. Schalekamp,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.