[Federal Register Volume 65, Number 91 (Wednesday, May 10, 2000)]
[Proposed Rules]
[Pages 30028-30031]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-11721]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-60-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 supersedure of an existing 
airworthiness directive (AD), applicable to certain McDonnell Douglas 
Model DC-8 series -10 through -50, -61, -61F, -71, -71F airplanes, that 
currently requires a visual or eddy current inspection(s) of the left 
and right wing front spar lower caps to detect cracks migrating from 
attachment holes; and repair, if necessary. That AD also provided for 
an optional terminating modification of the front spar lower cap. This 
proposal is prompted by a report that additional cracking was found in 
the front spar lower cap of a wing. This action would require 
accomplishment of the previously optional terminating action. The 
proposed AD also would expand the applicability of the existing AD to 
include additional airplanes and to increase the interval for the 
repetitive eddy current inspections. The actions specified by the 
proposed AD are intended to prevent reduced structural integrity of the 
left or right wing due to metal fatigue failure of the front spar lower 
cap.

DATES: Comments must be received by June 26, 2000.

[[Page 30029]]


ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-60-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, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; 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-60-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-60-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On September 26, 1986, the FAA issued AD 86-20-06, amendment 39-
5434 (51 FR 35502, October 6, 1986), applicable to certain McDonnell 
Douglas Model DC-8-10 through -50 inclusive, -61, -61F, -71, -71F 
series airplanes, to require repetitive visual or eddy current 
inspections to detect cracks of the left and right wing front spar 
lower caps between stations Xfs=515.00 and Xfs=526.760; and repair, if 
necessary. That AD also provides for an optional terminating 
modification for the repetitive inspection requirements. That action 
was prompted by reports of fatigue cracking on the spar caps of two 
airplanes. The requirements of that AD are intended to prevent reduced 
structural integrity of the left or right wing due to metal fatigue 
failure of the front spar lower cap.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 86-20-06, the FAA has received a report of 
two instances in which cracking was found in the front spar lower cap 
of a wing on affected airplanes that have accumulated between 46,093 
and 48,942 flight hours. The cracking originated at an attachment hole 
in the forward leg and progressed to a point partially through the 
vertical and aft leg of the spar cap. The cause of such cracking has 
been attributed to material fatigue. The FAA has determined that 
accomplishment of the visual inspection(s) required by AD 86-20-06 does 
not adequately ensure timely detection of fatigue cracks in the subject 
area.

Explanation of Relevant Service Information

    Subsequent to the finding of this new cracking, the manufacturer 
issued, and the FAA reviewed and approved McDonnell Douglas Service 
Bulletin DC8-57-090, Revision 05, dated June 16, 1997. The eddy current 
inspection and modification procedures are identical to those described 
in McDonnell Douglas DC-8 Service Bulletin 57-90, dated October 3, 1983 
(which was referenced as the appropriate source of service information 
in AD 86-20-06). The only changes effected by Revision 05 of the 
service bulletin are to remove the inadequate visual inspection 
procedures; to add additional airplanes to the effectivity listing; and 
to add an inspection following accomplishment of the preventative 
modification. 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 supersede AD 86-20-06 to continue to require an eddy 
current inspection(s) to detect cracks of the lower front spar caps of 
the wings at the attachment holes of the leading edge assembly between 
stations Xfs=515.000 and Xfs=526.760, and corrective actions, if 
necessary. The proposed AD would require accomplishment of the 
previously optional terminating action and a follow-on inspection. The 
proposed AD also would expand the applicability of the existing AD to 
include additional airplanes that are subject to the identified unsafe 
condition of this AD and to increase the interval for the repetitive 
eddy current inspections.

Differences Between the Proposed Rule and the Service Bulletin

    Operators should note that, although the service bulletin 
recommends that the repetitive eddy current inspections be accomplished 
at intervals not to exceed 3,600 flight hours or 1 year, whichever 
occurs first, the proposed AD would require those inspection at 
intervals not to exceed 3,600 flight hours or 3 years, whichever occurs 
first. The FAA consulted with the manufacturer and has determined 
through a damage tolerance assessment that the subject fatigue cracking 
is dependant only on flight hours. However, because some affected 
airplanes have very low utilization rates, the FAA has determined that 
extending the calendar year repetitive inspection interval from 1 year 
to 3 years will ensure that the inspection is accomplished within an 
acceptable time frame. Therefore, the proposed rule would require that 
the eddy current inspection interval be 3,600 flight hours or 3 years, 
whichever occurs first.
    Although the service bulletin recommends accomplishing the eddy

[[Page 30030]]

current inspection within 3,200 flight hours after the issue date of 
the service bulletin on airplanes that have accumulated 30,000 total 
flight hours, the proposed AD requires, for certain airplanes, that the 
inspection be accomplished within 3,200 flight hours or 2 years after 
the effective date of this AD, whichever occurs first. In developing an 
appropriate compliance time for this AD, the FAA considered not only 
the manufacturer's recommendation, but the degree of urgency associated 
with addressing the subject unsafe condition, the average utilization 
of the affected fleet, and the time necessary to perform the inspection 
(two hours). In addition, the FAA has determined that all affected 
airplanes have accumulated 30,000 or more total flight cycles. In light 
of all of these factors, the FAA finds a compliance time of within 
3,200 flight hours or 2 years after the effective date of this AD, 
whichever occurs first, for initiating the proposed actions to be 
warranted, in that it represents an appropriate interval of time 
allowable for affected airplanes to continue to operate without 
compromising safety.

Cost Impact

    There are approximately 294 Model DC-8 series 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.
    It would take approximately 2 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 $30,120, or 
$120 per airplane, per inspection cycle.
    It would take approximately between 12 and 14 work hours per 
airplane to accomplish the proposed modification, and that the average 
labor rate is $60 per work hour. Required parts would cost 
approximately between $303 and $1,202 per airplane. Based on these 
figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be between $256,773, or $512,542, or between $1,023, or 
$2,042 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.

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 removing amendment 39-5434 (51 FR 
35502, October 6, 1986), and by adding a new airworthiness directive 
(AD), to read as follows:

McDonnell Douglas: Docket 99-NM-60-AD. Supersedes AD 86-20-06, 
Amendment 39-5434.

    Applicability: Model DC-8 series airplanes, as listed in 
McDonnell Douglas Service Bulletin DC8-57-090, Revision 05, dated 
June 16, 1997; 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 (h)(1) 
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 reduced structural integrity of the left or right 
wing due to metal fatigue failure of the front spar lower cap, 
accomplish the following:

    Note 2: This AD will affect the inspections, corrective actions, 
and reports required by AD 93-01-15, amendment 39-8469 (58 FR 5576, 
January 22, 1993), for Principal Structural Elements (PSE) 57.08.021 
and 57.08.022 of the DC-8 Supplemental Inspection Document (SID).


    Note 3: Where there are differences between this AD and the 
referenced service bulletin, the AD prevails.

Eddy Current Inspection

    (a) For Model DC-8-10 through DC-8-50, inclusive, DC-8-61, -61F, 
-71, and -71F series airplanes, equipped with left or right wing 
front spar lower cap, part number (P/N) 5597838-1 or -2; not 
modified in accordance with McDonnell Douglas DC-8 Service Bulletin 
57-90, dated October 3, 1983: Perform an eddy current inspection to 
detect cracks of the lower front spar caps of the wings at the 
attachment holes of the leading edge assembly between stations 
Xfs=515.000 and Xfs=526.760, in accordance with McDonnell Douglas 
Service Bulletin DC8-57-090, Revision 05, dated June 16, 1997; at 
the time specified in either paragraph (a)(1), (a)(2), or (a)(3) of 
this AD, as applicable.

    Note 4: Eddy current inspections accomplished prior to the 
effective date of this AD in accordance McDonnell Douglas DC-8 
Service Bulletin 57-90, Revision 1, dated June 16, 1988; Revision 2, 
dated March 1, 1991; Revision 3, dated March 25, 1992; or Revision 
4, dated March 3, 1995; are considered acceptable for compliance 
with the requirements of paragraph (a) of this AD.

    (1) For airplanes on which the immediately preceding inspection 
was conducted using eddy current techniques in accordance with AD 
86-20-06 prior to the effective date of this AD: Inspect within 
3,600 flight hours or 3 years after accomplishment of the last eddy 
current inspection, whichever occurs first.
    (2) For airplanes on which the immediately preceding inspection 
was conducted visually in accordance with AD 86-20-06 prior to the 
effective date of this AD: Inspect within 3,200 flight hours or 2 
years after accomplishment of the last visual inspection, whichever 
occurs first.
    (3) For airplanes on which a visual or eddy current inspection 
or the modification required by AD 86-20-06 has not been 
accomplished: Inspect prior to the accumulation of 30,000 total 
flight hours, or within 200 flight hours after the effective date of 
this AD.

[[Page 30031]]

    (b) For airplanes other than those identified in paragraph (a) 
of this AD: Within 3,200 flight hours or 2 years after the effective 
date of this AD, whichever occurs first, perform the eddy current 
inspection specified in paragraph (a) of this AD.

Repetitive Inspections

    (c) If no crack is detected during any inspection required by 
this AD, repeat the eddy current inspection thereafter at intervals 
not to exceed 3,600 flight hours or 3 years, whichever occurs first.

Repair

    (d) If any crack is detected during any inspection required this 
AD, prior to further flight, accomplish the action specified in 
either paragraph (d)(1) or (d)(2) of this AD, as applicable.
    (1) For cracks within the limits specified in Conditions 2 
through 6, inclusive, Table 1 of paragraph 3.B.4 of the 
Accomplishment Instructions of McDonnell Douglas Service Bulletin 
DC8-57-090, Revision 05, dated June 16, 1997: Modify the lower front 
spar cap in accordance with McDonnell Douglas Service Bulletin DC8-
57-090, Revision 05, dated June 16, 1997. Accomplishment of the 
modification constitutes compliance with the requirements paragraphs 
(c) and (e) of this AD.
    (2) For cracks that exceed the limits specified in Conditions 2 
through 6, inclusive, Table 1 of paragraph 3.B.4 of the 
Accomplishment Instructions of McDonnell Douglas Service Bulletin 
DC8-57-090, Revision 05, dated June 16, 1997: Repair in accordance 
with a method approved by the Manager, Los Angeles Aircraft 
Certification Office (ACO), FAA, Transport Airplane Directorate.

Preventative Modification

    (e) Within 100,000 flight hours after the effective date of this 
AD, modify the lower front spar cap in accordance with paragraph 
3.B.2.B of the Accomplishment Instructions of McDonnell Douglas 
Service Bulletin DC8-57-090, Revision 05, dated June 16, 1997. 
Accomplishment of the modification constitutes compliance with the 
requirements paragraphs (a), (b), and (c) of this AD.

    Note 5: Modification of the lower front spar cap accomplished 
prior to the effective date of this AD in accordance with McDonnell 
Douglas DC-8 Service Bulletin 57-90, Revision 1, dated June 16, 
1988; Revision 2, dated March 1, 1991; Revision 3, dated March 25, 
1992; or Revision 4, dated March 3, 1995; is considered acceptable 
for compliance with the requirements of paragraph (d) of this AD.

    (f) Accomplishment of the modification required by paragraph B. 
of AD 90-16-05, amendment 39-6614 (55 FR 31818, August 6, 1990) 
[which references ``DC-8 Aging Aircraft Service Action Requirements 
Document'' (SARD), McDonnell Douglas Report MDC K1579, Revision A, 
dated March 1, 1990, as the appropriate source of service 
information for accomplishing the modification] constitutes 
compliance with paragraphs (a), (b), (c), and (e) of this AD.

Follow-On Inspection

    (g) Prior to the accumulation of 32,900 total flight hours 
following accomplishment of the modification required by either 
paragraph (d)(1) or (e) of this AD, or 2 years after the effective 
date of this AD, whichever occurs later, perform an inspection to 
detect cracks in the area specified in paragraph (a) of this AD, and 
corrective actions, if necessary, in accordance with a method 
approved by the Manager, Los Angeles ACO.

Alternative Methods of Compliance

    (h)(1) 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 6: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (2) Alternative methods of compliance, approved previously in 
accordance with AD 86-20-06, amendment 39-5434, are approved as 
alternative methods of compliance with this AD.

Special Flight Permits

    (i) 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 May 3, 2000.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-11721 Filed 5-9-00; 8:45 am]
BILLING CODE 4910-13-U