[Federal Register Volume 60, Number 113 (Tuesday, June 13, 1995)]
[Proposed Rules]
[Pages 31124-31126]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-14399]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-49-AD]


Airworthiness Directives; McDonnell Douglas Model DC-10-10, -30, 
and -40 Series Airplanes, and KC-10 (Military) 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-10, -30, and -40 series airplanes, and KC-10 (military) airplanes. 
This proposal would require inspections to detect corrosion or cracking 
of the lower front spar cap and the skin panel of the horizontal 
stabilizer, and repair of corroded or cracked parts. This proposal 
would also require eventual modification of the horizontal stabilizer, 
which would terminate the inspection requirements. This proposal is 
prompted by reports indicating that corrosion, caused by water 
entrapment, was found on the horizontal stabilizer. The actions 
specified by the proposed AD are intended to prevent water entrapment 
and subsequent damage to the horizontal stabilizer, which could result 
in reduced controllability of the airplane.

DATES: Comments must be received by August 8, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-49-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 [[Page 31125]] p.m., Monday through Friday, 
except Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard, 
Long Beach, California 90846, Attention: Technical Publications 
Business Administration, Department 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: John Cecil, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (310) 627-5322; fax (310) 
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 95-NM-49-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-103, Attention: Rules 
Docket No. 95-NM-49-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports indicating that corrosion was 
found on the aft tang of the lower front spar cap of the horizontal 
stabilizer on McDonnell Douglas Model DC-10 series airplanes. 
Additionally, the FAA has received several reports indicating that 
corrosion was found on the lower skin panel of the horizontal 
stabilizer on these airplanes. Investigation has revealed that the 
corrosion was caused by water entrapment in the horizontal stabilizer. 
Such corrosion, if not detected and corrected in a timely manner, could 
result in damage to the spar cap and/or lower skin panel of the 
horizontal stabilizer, which could lead to reduced controllability of 
the airplane.
    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin 55-14, Revision 6, dated January 11, 1993, which describes 
procedures for repetitive visual inspections for corrosion of the lower 
front spar cap and skin panel of the horizontal stabilizer, and repair 
of corroded or cracked parts. The service bulletin also describes 
procedures for modifications of the lower front spar cap and the lower 
front skin panel of the horizontal stabilizer, which, if accomplished, 
would eliminate the need for repetitive inspections. The modification 
involves drilling a drain hole in the horizontal stabilizer to allow 
drainage of entrapped water, which will minimize the possibility of 
corrosion.
    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 repetitive visual inspections to detect 
corrosion or cracking of the lower front spar cap and the skin panel of 
the horizontal stabilizer, and repair of corroded or cracked parts. 
This proposed AD would also require the eventual modification of the 
lower front spar cap and the lower front skin panel of the horizontal 
stabilizer, which would terminate the repetitive inspection 
requirements. The actions would be required to be accomplished in 
accordance with the service bulletin described previously.
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been included in this notice to clarify this long-standing requirement.
    There are approximately 286 Model DC-10-10, DC-10-30, and DC-10-40 
airplanes, and KC-10 (military) airplanes of the affected design in the 
worldwide fleet. Approximately 142 airplanes of U.S. registry would be 
affected by this proposed AD.
    The FAA estimates that it would take approximately 26 work hours 
per airplane to accomplish the proposed inspection, at an average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
the proposed inspection on U.S. operators is estimated to be $221,520, 
or $1,560 per airplane, per inspection cycle.
    The FAA estimates that it would take approximately 241 work hours 
per airplane to accomplish the proposed terminating modification, at an 
average labor rate of $60 per work hour. Required parts would cost 
approximately $124,906 per airplane. Based on these figures, the total 
cost impact of the proposed terminating modification is estimated to be 
$19,789,972, or $139,366 per airplane.
    Based on these figures, the estimated total cost impact of the 
proposed requirements of this AD would be $20,011,492, or $140,926 per 
airplane.
    The total 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.
    Additionally, the FAA recognizes that the proposed modification 
would require a large number of work hours to accomplish. However, the 
5-year compliance time specified in paragraph (b) of this proposed AD 
should allow ample time for the terminating modification to be 
accomplished coincidentally with scheduled major airplane inspection 
and maintenance activities, thereby minimizing the costs associated 
with special airplane scheduling.
    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and [[Page 31126]] 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

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

McDonnell Douglas: Docket 95-NM-49-AD.

    Applicability: Model DC-10-10, -30, and -40 airplanes, and KC-10 
(military) airplanes; as listed in McDonnell Douglas Service 
Bulletin 55-14, Revision 6, dated January 11, 1993; 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 use the authority 
provided in paragraph (c) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent reduced controllability of the airplane, due to a 
damaged horizontal stabilizer, accomplish the following:
    (a) Within one year after the effective date of this AD, perform 
a visual inspection to detect corrosion or cracking of the lower 
front spar cap and skin panel of the horizontal stabilizer, in 
accordance with McDonnell Douglas DC-10 Service Bulletin 55-14, 
Revision 5, dated August 24, 1990, or Revision 6, dated January 11, 
1993.
    (1) If no corrosion or cracking is found during this inspection, 
repeat this inspection thereafter at intervals not to exceed one 
year, until the modification required by paragraph (b) of this AD is 
accomplished.
    (2) If any corrosion or cracking is found during this 
inspection, prior to further flight, repair the corrosion and/or 
cracking, and add drain holes, in accordance with Table 1 of the 
service bulletin. Accomplishment of these repairs and modification 
constitutes terminating action for the repetitive inspection 
requirements of this AD.
    (b) Perform the modification of the lower front spar cap and the 
skin panel of the horizontal stabilizer in accordance with McDonnell 
Douglas Service Bulletin 55-14, Revision 5, dated August 24, 1990, 
or Revision 6, dated January 11, 1993, at the applicable time 
specified in paragraph (b)(1) or (b)(2) of this AD. Accomplishment 
of this modification constitutes terminating action for the 
repetitive inspection requirements of this AD.
    (1) For Model DC-10-10 airplanes: Prior to the accumulation of 
42,000 total landings, or within five years after the effective date 
of the AD, whichever occurs later.
    (2) For Model DC-10-30 and DC-10-40 airplanes: Prior to the 
accumulation of 30,000 total landings, or within five years after 
the effective date of this AD, whichever occurs later.
    (c) 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, 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.

    (d) 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 June 7, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-14399 Filed 6-12-95; 8:45 am]
BILLING CODE 4910-13-U