[Federal Register Volume 64, Number 207 (Wednesday, October 27, 1999)]
[Proposed Rules]
[Pages 57792-57794]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-28077]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-217-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-8 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 
DC-8 series airplanes. This proposal would require a one-time eddy 
current conductivity test to determine the material type of the lower 
cap of the wing front spar; and modification of the lower cap of the 
wing front spar, if necessary. This proposal is prompted by reports of 
stress corrosion cracking in the forward tang of the lower caps of the 
wing front spar. The actions specified by the proposed AD are intended 
to prevent such stress corrosion cracking,

[[Page 57793]]

which if not corrected, could result in reduced structural integrity of 
the wing.

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. 99-NM-217-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, 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 99-NM-217-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. 99-NM-217-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports of stress corrosion cracking in the 
forward tang of the lower cap of the wing front spar of McDonnell 
Douglas Model DC-8 series airplanes. Investigation revealed that some 
front spar lower caps were manufactured from 7079-T6 material, which is 
susceptible to stress corrosion cracking. This condition, if not 
corrected, could result in reduced structural integrity of the wing.

Other Relevant Rulemaking

    AD 90-16-05, amendment 39-6614 (55 FR 31818, August 6, 1990) 
requires certain inspections and structural modifications. McDonnell 
Douglas Service Bulletin DC8-57-030, Revision 3, dated December 10, 
1970, was mandated as part of the service action requirements program 
required by AD 90-16-05. Revision 3 of the service bulletin describes 
procedures for a one-time visual inspection for cracks in the forward 
tang of the lower cap of the front spar, and modification, if cracking 
is detected.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin DC8-57-030, Revision 04, dated August 17, 1995; and Revision 
05, dated April 28, 1998. Revisions 04 and 05 of the service bulletin 
describe procedures for a one-time eddy current conductivity test to 
determine the material type of the forward tang of the lower cap of the 
wing front spar, and modification of the front spar, if necessary. The 
modification involves replacement of lower cap of the wing front spar 
with a new lower cap. Revision 04 of the service bulletin recommends 
that airplanes previously modified in accordance with Revision 3 of the 
service bulletin be reworked if the lower cap was made of 7079-T6 
material. (Revision 04 of the service bulletin was approved as an 
alternative method of compliance to AD 90-16-05.) Revision 05 of the 
service bulletin adds 52 additional airplanes to the list of effective 
airplane serial numbers. 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 require accomplishment of the actions specified in 
the service bulletin described previously.

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 
3 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 proposed AD on U.S. operators is 
estimated to be $45,180, or $180 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.

[[Page 57794]]

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 99-NM-217-AD.

    Applicability: Model DC-8 series airplanes, as listed in 
McDonnell Douglas Service Bulletin DC8-57-30, Revision 05, dated 
April 28, 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 (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 stress corrosion cracking of the lower cap of the 
wing front spar, which if not corrected, could result in reduced 
structural integrity of the wing, accomplish the following:
    (a) Within 48 months after the effective date of this AD, 
perform a one-time eddy current conductivity test to determine the 
material type of the forward tang of the lower cap of the front spar 
in the center section of the wing, in accordance with McDonnell 
Douglas Service Bulletin DC8-57-30, Revision 05, dated April 28, 
1998, or Revision 04, dated August 17, 1995.
    (1) If 7079-T6 aluminum is not found, no further action is 
required by this AD.
    (2) If any 7079-T6 aluminum is found, within 48 months after the 
effective date of this AD, modify the forward tang of the lower cap 
of the front spar, in accordance with the service bulletin.
    (b) Accomplishment of the eddy current conductivity test, and 
modification, if necessary, specified in paragraph (a) of this AD 
constitutes terminating action for the repetitive inspection 
requirements of paragraph (a) of AD 90-16-05, amendment 39-6614, as 
it applies to the inspections of the forward tang of the lower cap 
of the front spar specified in McDonnell Douglas Service Bulletin 
DC8-57-30, Revision 3, dated December 10, 1970.

Alternative Methods of Compliance

    (c) An alternative method of compliance that provides an 
acceptable level of safety may be used if approved by the Manager, 
Los Angeles Aircraft Certification Office (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 2: 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

    (d) 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. 99-28077 Filed 10-26-99; 8:45 am]
BILLING CODE 4910-13-U