[Federal Register Volume 63, Number 80 (Monday, April 27, 1998)]
[Proposed Rules]
[Pages 20548-20550]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-11089]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-110-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9 and C-9 
(Military) 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-9 and C-9 (military) series airplanes. This proposal would require 
repetitive inspections to detect fatigue cracking of the fuselage 
frames and longerons 16R

[[Page 20549]]

and 17R above the forward lower cargo door; repair, if necessary; and 
modification of the fuselage frames and longerons, if necessary, and 
follow-on repetitive inspections to detect fatigue cracking of the skin 
adjacent to the modification. This proposal is prompted by numerous 
instances of fatigue cracking of the fuselage frames and longerons. The 
actions specified by the proposed AD are intended to prevent fatigue 
cracking of the fuselage frames and longerons 16R and 17R, which could 
result in reduced structural integrity of the airplane.

DATES: Comments must be received by June 11, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-110-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 The Boeing Company, Douglas Products Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Technical 
Publications Business Administration, ept. 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: Wahib Mina, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (562) 627-5324; 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-110-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-110-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    Operators have reported to the FAA numerous instances of fatigue 
cracks on in-service McDonnell Douglas Model DC-9 series airplanes in 
the fuselage frames and longerons 16R and 17R above the forward lower 
cargo door. These cracks were discovered during inspections conducted 
as part of the Supplemental Structural Inspection Document (SSID) 
program, required by AD 96-13-03, amendment 39-9671 (61 FR 31009, June 
19, 1996). Investigation has revealed that such cracking was caused by 
fatigue-related stress. Such fatigue cracking, if not corrected, could 
result in reduced structural integrity of the airplane.
    The subject area on certain Model C-9 (military) series airplanes 
is identical to that on the affected Model DC-9 series airplanes; 
therefore, both models may be subject to the same unsafe condition.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin DC9-53-267, dated October 20, 1997, which describes procedures 
for repetitive visual inspections to detect fatigue cracking of the 
fuselage frames and longerons 16R and 17R above the forward lower cargo 
door, and repair of any cracking of the fuselage frames and longerons 
16R and 17R. The service bulletin also describes procedures for 
modification of the fuselage frames and longerons 16R and 17R, if 
necessary, and follow-on repetitive visual inspections to detect 
fatigue cracking of the skin adjacent to the 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 require accomplishment of the actions specified in 
the service bulletin described previously.

Cost Impact

    There are approximately 887 airplanes of the affected designs in 
the worldwide fleet. The FAA estimates that 582 airplanes of U.S. 
registry would be affected by this proposed AD. It would take 
approximately 1 work hour per airplane to accomplish the proposed 
inspection, at an average labor rate of $60 per work hour. Based on 
this figure, the cost impact of the proposed inspection on U.S. 
operators is estimated to be $34,920, or $60 per airplane, per 
inspection cycle.
    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.
    Should an operator be required to accomplish the proposed 
modification, it would take approximately 4 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Required 
parts would cost approximately $860 or $713 per airplane, depending on 
the service kit purchased. Based on these figures, the cost impact of 
the proposed modification is estimated to be as high as $1,100 and as 
low as $953 per airplane.
    Should an operator be required to accomplish the proposed follow-on 
inspection of the fuselage skin, it would take approximately 1 work 
hour per airplane to accomplish the proposed inspection, at an average 
labor rate of $60 per work hour. Based on this figure, the cost impact 
of the proposed inspection on U.S. operators is estimated to be $60 per 
airplane, per inspection cycle.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship

[[Page 20550]]

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-110-AD.

    Applicability: Model DC-9 and C-9 (military) series airplanes, 
as listed in McDonnell Douglas Service Bulletin DC9-53-267, dated 
October 20, 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 (e) 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 fuselage frames and longerons 
16R and 17R, which could result in reduced structural integrity of 
the airplane, accomplish the following:

    Note 2: This AD will affect Principal Structural Element (PSE) 
53.09.055A of the DC-9 Supplemental Inspection Document (SID).

    (a) Prior to the accumulation of 30,000 total landings, or 
within 3,000 landings after the effective date of this AD, whichever 
occurs later, perform a visual inspection to detect fatigue cracking 
of the fuselage frames and longerons 16R and 17R above the forward 
lower cargo door, in accordance with McDonnell Douglas Service 
Bulletin DC9-53-267, dated October 20, 1997.
    (b) Condition 1. If no cracking is detected during the 
inspection required by paragraph (a) of this AD, accomplish the 
requirements of either paragraph (b)(1) or (b)(2) of this AD, in 
accordance with McDonnell Douglas Service Bulletin DC9-53-267, dated 
October 20, 1997.
    (1) Option 1. Repeat the visual inspection thereafter at 
intervals not to exceed 19,000 landings. Or
    (2) Option 2. Prior to further flight, modify the fuselage 
frames and longerons 16R and 17R. Prior to the accumulation of 
19,000 landings after accomplishment of the modification, perform a 
visual inspection to detect fatigue cracking of the skin adjacent to 
the modification.
    (i) If no cracking is detected, repeat the visual inspection 
thereafter at intervals not to exceed 19,000 landings.
    (ii) If any cracking is detected, prior to further flight, 
repair in accordance with a method approved by the Manager, Los 
Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate.
    (c) Condition 2. If any cracking is detected during the 
inspection required by paragraph (a) of this AD, prior to further 
flight, repair the cracked area and modify the fuselage frames and 
longerons 16R and 17R; in accordance with McDonnell Douglas Service 
Bulletin DC9-53-267, dated October 20, 1997. Prior to the 
accumulation of 19,000 landings after accomplishment of the 
modification, perform a visual inspection to detect fatigue cracking 
of the skin adjacent to the modification; in accordance with the 
service bulletin.
    (1) If no cracking is detected, repeat the visual inspection 
thereafter at intervals not to exceed 19,000 landings.
    (2) If any cracking is detected, prior to further flight, repair 
in accordance with a method approved by the Manager, Los Angeles 
ACO.
    (d) Accomplishment of the actions required by this AD 
constitutes terminating action for the requirements of AD 96-13-03, 
amendment 39-9671, for PSE 53.09.055A only of the DC-9 SID.
    (e) 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (f) 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 April 21, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-11089 Filed 4-24-98; 8:45 am]
BILLING CODE 4910-13-U