Airworthiness Directives; McDonnell Douglas Model DC-8 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-309-AD]

RIN 2120-AA64

Airworthiness Directives; McDonnell Douglas Model DC-8 Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to certain McDonnell Douglas Model

DC-8 series airplanes. This proposal would require detailed visual and

eddy current inspections of the lower wing skin at the 3 outboard

fasteners of the stringer 64 end fitting to detect cracks; and

corrective actions, if necessary. This proposal is prompted by reports

of fatigue cracks found in the lower wing skin initiating from the

outboard fasteners of the stringer 64 end fitting. The actions

specified by the proposed AD are intended to prevent such fatigue

cracking, which could reduce structural integrity and loss of fail-safe

capability of the airplane.

DATES: Comments must be received by December 13, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 98-NM-309-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 Boeing Commercial Aircraft Group, Long Beach Division,

3855 Lakewood Boulevard, Long Beach, California 90846, Attention:

Technical Publications Business Administration, Dept. 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: Greg DiLibero, Aerospace Engineer,

Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los

Angeles Aircraft Certification Office, 3960 Paramount Boulevard,

Lakewood, California 90712-4137; telephone (562) 627-5231; 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 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 98-NM-309-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. 98-NM-309-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

The FAA has received reports of fatigue cracks in the lower wing

skin at the 3 outboard fasteners of the stringer 64 end fitting. These

cracks were discovered during inspections conducted as part of the

Supplemental Inspection Document (SID) program, required by AD 93-01-

15, amendment 39-8469 (58 FR 5576, January 22, 1993). Investigation

revealed that such cracking was caused by fatigue-related stress.

Fatigue cracking of the wing skin at the 3 outboard fasteners of the

stringer 64 end fitting, if not detected in a timely manner, could

result in reduced structural integrity and loss of fail-safe capability

of the airplane.

Explanation of Relevant Service Information

The FAA has reviewed and approved McDonnell Douglas Service

Bulletin DC8-57-100, Revision 01, dated August 26, 1998. The service

bulletin describes procedures for detailed visual and eddy current

inspections to detect cracks of the lower wing skin at the 3 outboard

fasteners of the stringer 64 end fitting; and corrective actions, if

necessary. The corrective actions involve accomplishing a preventative

modification (including stress or split sleeve coining of holes, and

installing new pins), replacing pins with new pins, and repairing, as

applicable. 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.

[[Page 57807]]

Differences Between Proposed Rule and Service Bulletin

Operators should note that, although the service bulletin specifies

that the manufacturer may be contacted for disposition of certain

repair conditions, this proposal would require the repair of those

conditions to be accomplished in accordance with a method approved by

the FAA.

Operators should also note that the repair procedures for Condition

2 of the Work Instructions of the service bulletin do not provide for a

follow-on inspection of the repaired area. The FAA has determined that

a follow-on inspection of the repaired area is necessary to provide an

appropriate level of safety.

Cost Impact

There are approximately 294 airplanes of the affected design in the

worldwide fleet. The FAA estimates that 251 airplanes of U.S. registry

would be affected by this proposed AD, that it would take approximately

4 work hours per airplane to accomplish the proposed inspection, and

that the average labor rate is $60 per work hour. Based on these

figures, the cost impact of the inspection proposed by this AD on U.S.

operators is estimated to be $60,240, or $240 per airplane.

The cost impact figure discussed above is 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 adding the following new

airworthiness directive:

McDonnell Douglas: Docket 98-NM-309-AD.

Applicability: Model DC-8 series airplanes, as listed in

McDonnell Douglas Service Bulletin DC8-57-100, Revision 01, dated

August 26, 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 (b) 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 fatigue cracking of the lower wing skin, which could

reduce structural integrity and loss of fail-safe capability of the

airplane, accomplish the following:

Note 2: This AD will affect Principal Structural Elements (PSE)

57.08.037, 57.08.038, 57.08.021, and 57.08.022 of the DC-8

Supplemental Inspection Document (SID).

Inspection, Repair, and Modification

(a) Within 24 months after the effective date of this AD,

perform detailed visual and eddy current inspections to detect

cracks in the lower wing skin fastener holes in the area surrounding

3 outboard fasteners of the stringer 64 end fitting, in accordance

with McDonnell Douglas Service Bulletin DC8-57-100, Revision 01,

dated August 26, 1998.

Note 3: 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.''

(1) If any crack is detected in the skin fastener holes and it

is less than 3.1 inches long, prior to further flight, repair in

accordance with the service bulletin. Within 14,100 landings after

accomplishment of the repair, inspect the lower wing skin to detect

cracks, in accordance with a method approved by the Manager, Los

Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane

Directorate.

(2) If any crack is detected in the skin fastener holes and it

is greater than or equal to 3.1 inches long, prior to further

flight, repair in accordance with a method approved by the Manager

Los Angeles ACO.

(3) If no crack is found, within 24 months after the effective

date of this AD, accomplish the preventative modification (including

stress or split sleeve coining the three fastener holes in the skin,

and installing new pins), in accordance with the service bulletin.

Accomplishment of this action constitutes terminating action for the

requirements of this AD.

Note 4: This AD does not terminate the inspection requirements

for PSE's 57.08.037, 57.08.038, 57.08.021, and 57.08.022 of the DC-8

SID in accordance with AD 93-01-15, amendment 39-6330.

Alternative Methods of Compliance

(b) 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, FAA, Transport

Airplane Directorate. 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 5: 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

(c) Special flight permits may be issued in accordance with

Secs. 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 October 21, 1999.

D. L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-28085 Filed 10-26-99; 8:45 am]

BILLING CODE 4910-13-P