01-17606. Airworthiness Directives; McDonnell Douglas Model DC-8-70 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all McDonnell Douglas Model DC-8-70 series airplanes, that currently requires repetitive inspections and repair or replacement, if necessary, of the generator power feeder cables, supporting brackets, and clamps at all the engine pylons. This action would require accomplishment of a terminating action for the repetitive inspections. This action also would require replacement of the support clamps of the generator power feeder cable on engine nacelles/pylons 1, 2, 3, and 4 with new support clamps. This proposal is prompted by the FAA's determination that further rulemaking is necessary. The actions specified by the proposed AD are intended to prevent a fire on the ground if a fuel leak exists in an engine pylon.

DATES:

Comments must be received by September 6, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-222-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. 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-222-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 for Windows 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:

Elvin Wheeler, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, 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-222-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-222-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Background

In July 1996, a Boeing Model 747 series airplane was involved in an accident. As part of re-examining all aspects of the service experience of the airplane involved in the accident, the FAA participated in design review and testing to determine possible sources of ignition in center fuel tanks. As part of the review, we examined fuel system wiring with regard to the possible effects that wire degradation may have on arc propagation.

In 1997 in a parallel preceding, at the recommendation of the White House Commission on Aviation Safety and Security, the FAA expanded its Aging Transport Program to include non-structural systems and assembled a team for evaluating these systems. This team performed visual inspections of certain transport category airplanes for which 20 years or more had passed since date of manufacture. In addition, the team gathered information from interviews with FAA Principal Maintenance Inspectors and meetings with representatives of airplane manufacturers. This evaluation revealed that the length of time in service is not the only cause of wire degradation; inadequate maintenance, contamination, improper repair, and mechanical damage are all contributing factors. From the compilation of this comprehensive information, we developed the Aging Transport Non-Structural Systems Plan to increase airplane safety by increasing knowledge of how non-structural systems degrade and how causes of degradation can be reduced.

In 1998, an accident occurred off the coast of Nova Scotia involving a McDonnell Douglas Model MD-11 series airplane. Investigation indicates that a fire broke out in the cockpit and first class overhead area. Although the ignition source of the fire has not been determined, the FAA, in conjunction with Boeing and operators of Model MD-11, DC-8, DC-9, DC-10, and DC-9-80 series airplanes, is reviewing all aspects of the service history of those airplanes to identify potential unsafe conditions associated with wire degradation due to various contributing factors (e.g., inadequate maintenance, contamination, improper repair, and mechanical damage) and to take appropriate corrective actions. We have issued a series of airworthiness directives (AD) that address unsafe conditions identified during that process. This process is continuing and we may consider additional rulemaking actions as further results of the review become available. The cause of the Nova Scotia MD-11 accident has not yet been determined.

In 1999, the FAA Administrator established a formal advisory committee to facilitate the implementation of the Aging Transport Non-Structural Systems Plan. This committee, the Aging Transport Systems Rulemaking Advisory Committee (ATSRAC), is made up of representatives of airplane manufacturers, operators, user groups, aerospace and industry associations, and government agencies. As part of its mandate, ATSRAC will recommend rulemaking to increase transport category airplane safety in cases where solutions to safety problems connected to aging systems have been found and must be applied. Detailed analyses of certain transport category airplanes that have been removed from service, studies of service bulletins pertaining to certain wiring systems, and reviews of previously issued ADs requiring repetitive inspections of certain wiring systems, have resulted in valuable information on the cause and prevention of wire degradation due to various contributing factors (e.g., inadequate maintenance, contamination, improper repair, and mechanical damage).

In summary, as a result of the investigations described above, the FAA has determined that corrective action may be necessary to minimize the potential hazards associated with wire degradation and related causal factors (e.g., inadequate maintenance, contamination, improper repair, and mechanical damage).

Previously Issued AD 88-11-03

On May 3, 1988, the FAA issued AD 88-11-03, amendment 39-5922 (53 FR 17018, May 13, 1988), applicable to all McDonnell Douglas Model DC-8-70 series airplanes, to require repetitive inspections and repair or replacement, if necessary, of the generator power feeder cables, supporting brackets, and clamps at the engine pylons. That action was prompted by reports indicating that the generator power feeder cable was chafing against the clamp and support bracket, resulting in shorting to the clamp, bracket, and structure in an engine pylon area. The requirements of that AD are intended to prevent a fire on the ground if a fuel leak exists in an engine pylon.

Actions Since Issuance of AD 88-11-03

Since the issuance of AD 88-11-03, the FAA has determined that long-term continued operational safety will be better assured by design changes to remove the source of the problem, rather than by repetitive inspections. Long-term inspections may not be providing the degree of safety assurance necessary for the transport airplane fleet. This, coupled with a better understanding of the human factors associated with numerous continual inspections, has led us to consider placing less emphasis on inspections and more emphasis on design improvements. Therefore, we now have determined that further rulemaking action is necessary to require a terminating action for the repetitive inspection and verification requirements of AD 88-11-03.

In addition, the airplane manufacturer has informed the FAA of the possibility that support clamps of the generator power feeder cable in the forward pylon and engine nacelle areas could fail on airplanes subject to the requirements of AD 88-11-03. The cause has been attributed to the generator power feeder cable chafing against the support clamps and bracket. Such chafing, if not corrected, could result in electrical arcing and damage to the primary structure in the engine pylon area, which could result in a fire on the ground if a fuel leak exists in the engine pylon area.

Other Related Rulemaking

This proposed AD is one of a series of actions identified as part of the ATSRAC program initiative to maintain continued operational safety of aging non-structural systems in transport category airplanes. The program is continuing and the FAA may consider additional rulemaking actions as further results of the review become available.

Explanation of Relevant Service Information

The FAA has reviewed and approved McDonnell Douglas DC-8-70 Service Bulletin 24-72, dated January 14, 1992, which describes procedures for replacement of the support clamps of the generator power feeder cable on engine pylons 1, 2, 3, and 4 with new support clamps.

The FAA also has reviewed and approved McDonnell Douglas DC-8-70 Service Bulletin 24-71, Revision 1, dated February 25, 1991. The service bulletin describes procedures for performing an inspection of the terminal connections of the generator power feeder cable for general condition and to verify that the ground studs are tight and that the nuts securing the cable terminals to the terminal strip are tightened to a torque of 120 to 130 inch-pound; tightening terminal connections, if necessary; and applying a coat of certain sealants.

Accomplishment of the actions specified in McDonnell Douglas DC-8-70 Service Bulletin 24-72 and McDonnell Douglas DC-8-70 Service Bulletin 24-71 would eliminate the need for the repetitive inspection requirements of AD 88-11-03.

In addition, the FAA has reviewed and approved McDonnell Douglas DC-8-70 Service Bulletin 24-73, dated May 30, 1990, which describes procedures for replacement of the support clamps of the generator power feeder cable in the forward pylon on engine nacelles 1, 2, 3, and 4 with new support clamps.

Accomplishment of the actions specified in the service bulletins 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 supersede AD 88-11-03 to continue to require repetitive inspections and repair or replacement, if necessary, of the generator power feeder cables, supporting brackets, and clamps at the engine pylons. The proposed AD also would require accomplishment of the actions specified in the service bulletins described previously, some of which would terminate the repetitive inspections.

Cost Impact

There are approximately 108 Model DC-8-70 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 98 airplanes of U.S. registry would be affected by this proposed AD.

The inspection that is currently required by AD 88-11-03, and retained in this proposed AD, takes approximately 12 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $70,560, or $720 per airplane, per inspection cycle.

The new replacement specified in McDonnell Douglas DC-8-70 Service Bulletin 24-72, dated January 14, 1992, that is proposed in this AD action would take approximately 3 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $675 per airplane. Based on these figures, the cost impact of this replacement proposed by this AD on U.S. operators is estimated to be $83,790, or $855 per airplane.

The new inspection and application of sealants specified in McDonnell Douglas DC-8-70 Service Bulletin 24-71, Revision 1, dated February 25, 1991, that are proposed in this AD action would take approximately 5 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection and application of sealants proposed by this AD on U.S. operators is estimated to be $29,400, or $300 per airplane.

The new replacement specified in McDonnell Douglas DC-8-70 Service Bulletin 24-73, dated May 30, 1990, that is proposed in this AD action would take approximately 16 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $715 per airplane. Based on these figures, the cost impact of the proposed requirements of this AD on U.S. operators is estimated to be $164,150, or $1,675 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this 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 removing amendment 39-5922 (53 FR 17018, May 13, 1988), and by adding a new airworthiness directive (AD), to read as follows:

McDonnell Douglas: Docket 2001-NM-222-AD. Supersedes AD 88-11-03, Amendment 39-5922.

Applicability: All Model DC-8-70 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 (g) 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 a fire on the ground if a fuel leak exists in an engine pylon, accomplish the following:

Restatement of Requirements of AD 88-11-03

Repetitive Inspections, Verification, and Corrective Actions, If Necessary

(a) Within 30 days after June 3, 1988 (the effective date of AD 88-11-03, amendment 39-5922), unless previously accomplished within the last 3,500 flight hours, inspect the generator power feeder cables, support brackets, and clamps between bulkhead feed-through at station YN=278.500 and terminal strip S3-7000 at engine pylons 1, 2, 3, and 4, for evidence of arcing, burning, chafing, damage, or cable droop, in accordance with the Accomplishment Instructions of McDonnell Douglas Service Bulletin A24-72, dated April 6, 1988.

(1) If no evidence of arcing, burning, chafing, damage, or drooping exists, proceed to paragraph (a)(3) of this AD.

(2) If any evidence of arcing, burning, chafing, damage, or drooping exists, prior to further flight, repair or replace parts, as required, in accordance with the service bulletin.

(3) Verify that the nuts securing cable terminals to terminal strip S3-7000 are tightened to a torque of 120 to 130 inch-pounds.

Repetitive Inspection Interval

(b) Repeat the procedures specified in paragraph (a) of this AD at intervals not to exceed 3,500 flight hours.

New Actions Required by This AD

Terminating Actions for Repetitive Inspections and Verification

(c) Within 1 year after the effective date of this AD, replace the support clamps of the generator power feeder cable on engine pylons 1, 2, 3, and 4 with new support clamps, in accordance with McDonnell Douglas DC-8-70 Service Bulletin 24-72, dated January 14, 1992. The requirements of paragraphs (a)(1) and (a)(2) of this AD must be done prior to or in conjunction with the requirements of this paragraph.

(d) Within 1 year after the effective date of this AD, do the actions specified in paragraphs (d)(1) and (d)(2) of this AD in accordance with McDonnell Douglas DC-8-70 Service Bulletin 24-71, Revision 1, dated February 25, 1991. The requirements of paragraph (a)(3) of this AD must be done prior to or in conjunction with the requirements of this paragraph.

(1) Do a general visual inspection of the terminal strip of the terminal connections of the generator power feeder cable for general condition (i.e., loose connections) and to verify that the ground studs are tight and that the nuts securing the cable terminals to the terminal strip are tightened to a torque of 120 to 130 inch-pound, in accordance with the service bulletin. If any terminal connection is loose, not tight, or torqued improperly, prior to further flight, tighten terminal connection in accordance with the service bulletin.

Note 2:

For the purposes of this AD, a general visual inspection is defined as “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

(2) Apply a coat of certain sealants per Figure 1 of the service bulletin.

(e) Accomplishment of the actions required by paragraphs (c) and (d) of this AD constitute terminating action for the requirements of paragraphs (a) and (b) of this AD.

Replacement of Certain Support Clamps

(f) Within 1 year after the effective date of this AD, replace the support clamps of the generator power feeder cable in the forward pylon on engine nacelles 1, 2, 3, and 4 with new support clamps, in accordance with McDonnell Douglas DC-8-70 Service Bulletin 24-73, dated May 30, 1990.

Alternative Methods of Compliance

(g) 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 Aircraft Certification Office (ACO), FAA. 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 3:

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

Special Flight Permits

(h) Special flight permits may be issued in accordance with §§ 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 July 9, 2001.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.