[Federal Register Volume 70, Number 233 (Tuesday, December 6, 2005)]
[Proposed Rules]
[Pages 72601-72604]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-23655]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-23197; Directorate Identifier 2005-NM-109-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-10, DC-9-
20, DC-9-30, DC-9-40, and DC-9-50 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain McDonnell Douglas Model DC-9-10, DC-9-20, DC-9-30, DC-9-40, 
and DC-9-50 series airplanes. This proposed AD would require repetitive 
inspections for stress corrosion cracks of the main fuselage frame, and 
corrective actions if necessary. This proposed AD also would provide an 
optional terminating action for the repetitive inspections. This 
proposed AD results from several reports of cracking of the main 
fuselage frame. We are proposing this AD to detect and correct stress 
corrosion cracking of the main fuselage frame, which could result in 
extensive damage to adjacent structure, and reduced structural 
integrity of the airplane.

DATES: We must receive comments on this proposed AD by January 20, 
2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
    <bullet> Fax: (202) 493-2251.
    <bullet> Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, Long Beach Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Data and 
Service Management, Dept. C1-L5A (D800-0024), for the service 
information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Wahib Mina, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5324; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Include the docket number ``FAA-
2005-23197; Directorate Identifier 2005-NM-109-AD'' at the beginning of 
your comments. We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of the proposed 
AD. We will consider all comments received by the closing date and may 
amend the proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR

[[Page 72602]]

19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    In April 1988, a high-cycle transport category airplane 
(specifically, a Boeing Model 737) was involved in an accident in which 
the airplane suffered major structural damage during flight. 
Investigation of this accident revealed that the airplane had numerous 
fatigue cracks and a great deal of corrosion. Subsequent inspections 
conducted by the operator on other high-cycle transport category 
airplanes in its fleet revealed that other airplanes had extensive 
fatigue cracking and corrosion.
    Prompted by the data gained from this accident, the FAA sponsored a 
conference on aging airplanes in June 1988, which was attended by 
representatives from the aviation industry and airworthiness 
authorities from around the world. It became obvious that, because of 
the tremendous increase in air travel, the relatively slow pace of new 
airplane production, and the apparent economic feasibility of operating 
older technology airplanes rather than retiring them, increased 
attention needed to be focused on the aging airplane fleet and 
maintaining its continued operational safety.
    The Air Transport Association (ATA) of America and the Aerospace 
Industries Association (AIA) of America agreed to undertake the task of 
identifying and implementing procedures to ensure the continued 
structural airworthiness of aging transport category airplanes. An 
Airworthiness Assurance Working Group (AAWG) was established in August 
1988, with members representing aircraft manufacturers, operators, 
regulatory authorities, and other aviation industry representatives 
worldwide. The objective of the AAWG was to sponsor ``Task Groups'' to:
    1. Select service bulletins, applicable to each airplane model in 
the transport fleet, to be recommended for mandatory modification of 
aging airplanes;
    2. Develop corrosion-directed inspections and prevention programs;
    3. Review the adequacy of each operator's structural maintenance 
program;
    4. Review and update the Supplemental Inspection Documents (SID); 
and
    5. Assess repair quality.
    In addition, we have received several reports of cracking of the 
main fuselage frame on McDonnell Douglas Model DC 9-10 series airplanes 
at station Y=642.000. The cracking has been attributed to stress 
corrosion. The AAWG task group for McDonnell Douglas Model DC-9-10, DC-
9-20, DC-9-30, DC-9-40, and DC-9-50 series airplanes has determined 
that we should mandate inspections for cracks of the main fuselage 
frame, and repair if necessary, in accordance with the service bulletin 
described below. Stress corrosion cracking, if not detected and 
corrected, could propagate and result in extensive damage to adjacent 
structure, and reduced structural integrity of the airplane.
    The subject area on certain McDonnell Douglas Model DC-9-20, DC-9-
30, DC-9-40, and DC-9-50 series airplanes is identical to that on the 
affected Model DC 9-10 series airplanes. Therefore, all of these models 
may be subject to the same unsafe condition.

Relevant Service Information

    We have reviewed McDonnell Douglas DC-9 Service Bulletin 53-168, 
dated November 17, 1983; including McDonnell Douglas Service Sketch 
3529, dated August 23, 1983 (attached to the service bulletin). The 
service bulletin describes procedures for repetitive inspections for 
stress corrosion cracks of the main fuselage frame at Station Y=642.000 
(for Model DC-9-10 and DC-9-20 series airplanes), Station Y=756.000 
(for Model DC-9-30 series airplanes), Station Y=794.000 (for Model DC-
9-40 series airplanes), and Station Y=851.000 (for Model DC-9-50 series 
airplanes). The service bulletin specifies that operators should use 
one of four inspection methods during each repetitive inspection cycle: 
optical-aided visual, dye-penetrant, eddy current, or ultrasonic. The 
service bulletin specifies that operators should record all inspection 
results, and send a report to the manufacturer. If no crack is found, 
the service bulletin provides procedures for repeating the inspection 
until the frame is replaced. If any crack is found in a pocket area and 
the crack is within the trim-out limits specified in Service Sketch 
3529, the service bulletin provides procedures for repeating the 
inspection until the frame is replaced. If any crack is found in a 
pocket area and the crack exceeds the trim-out limits specified in 
Service Sketch 3529, the service bulletin specifies that the corrective 
action is replacing the frame. In addition, if any crack is found in 
the web, the service bulletin specifies that the corrective action is 
replacing the frame. The service bulletin specifies that replacing the 
frame with a new or serviceable frame made of 7075-T73 aluminum 
material terminates the repetitive inspection requirements for that 
frame only. Accomplishing the actions specified in the service 
information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. For this reason, we are proposing this AD, 
which would require accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Differences Between the Proposed AD and the Service Information.''
    Operators should note that, while it is not the FAA's usual policy 
to allow flight with known cracks, this AD permits further flight with 
cracking within certain limits. The manufacturer has advised us that 
they have data showing that the fuselage frame with the trim-out area, 
specified in McDonnell Douglas Service Sketch 3529, meets the 
certification basis of the airplane. The cracked frame supports limit 
load without detrimental permanent deformation, and ultimate load 
without failure. The repetitive inspection interval of 3,400 flight 
hours for this area (specified in paragraph (h)(1) of this proposed AD) 
is intended to detect crack growth caused by stress corrosion until the 
terminating action is accomplished. In consideration of these findings 
and the FAA's criteria for flight with known cracking, further flight 
with cracking within certain limits is permissible.

Differences Between the Proposed AD and the Service Information

    Although the service bulletin referenced in this proposed AD 
specifies to submit certain information to the manufacturer, this 
proposed AD does not include that requirement.
    Although the service bulletin does not give a compliance time for 
replacing the frame if a crack is found in a pocket area and the crack 
exceeds the limits specified in Service Sketch 3529; or if a crack is 
found in the web; this

[[Page 72603]]

proposed AD would require doing that replacement before further flight.
    Although the service bulletin does not give a compliance time for 
doing the inspection for crack growth if a crack in the pocket area is 
within the trim-out limits specified in Service Sketch 3529, this 
proposed AD would require doing that inspection before further flight.

Clarification of Inspection Terminology

    In this proposed AD, the ``optical-aided visual inspection'' 
specified in the service bulletin is referred to as a ``detailed 
inspection.'' We have included the definition for a detailed inspection 
in a note in the proposed AD.

Costs of Compliance

    There are about 1,017 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                                     Estimated Costs
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                                                                                                                 Number  of
                                                          Average                                                  U.S.-
                  Action                    Work hours   labor rate     Parts           Cost per airplane        registered           Fleet cost
                                                          per hour                                               airplanes
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Inspection, per inspection cycle.........            2          $65           $0  $130, per inspection cycle..          376  $48,880, per inspection
                                                                                                                              cycle.
Optional terminating acton (replacing the       \1\ 96           65        7,305  $13,545.....................          376  Up to $5,092,920.
 frame).
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\1\ Per airplane.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

McDonnell Douglas: Docket No. FAA-2005-23197; Directorate Identifier 
2005-NM-109-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by January 
20, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to McDonnell Douglas Model DC-9-11, DC-9-12, 
DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-
9-32 (VC-9C), DC-9-32F, DC-9-33F, DC-9-34, DC-9-34F, DC-9-32F (C-9A, 
C-9B), DC-9-41, and DC-9-51 airplanes; certificated in any category; 
as identified in McDonnell Douglas DC-9 Service Bulletin 53-168, 
dated November 17, 1983.

Unsafe Condition

    (d) This AD results from several reports of cracking of the main 
fuselage frame. We are issuing this AD to detect and correct stress 
corrosion cracking of the main fuselage frame, which could result in 
extensive damage to adjacent structure, and reduced structural 
integrity of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Service Bulletin Reference

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of McDonnell Douglas DC-9 Service 
Bulletin 53-168, dated November 17, 1983, including McDonnell 
Douglas Service Sketch 3529, dated August 23, 1983.

Repetitive Inspections and Corrective Actions

    (g) Prior to the accumulation of 15,000 total flight hours, or 
within 3,400 flight hours after the effective date of this AD, 
whichever occurs later: Do a detailed inspection, dye-penetrant 
inspection, eddy current inspection, or ultrasonic inspection for 
stress corrosion cracks of the main fuselage frame in accordance 
with the service bulletin. Except as provided by paragraph (h) of 
this AD, repeat the inspection thereafter at intervals not to exceed 
8,000 flight hours until the replacement in paragraph (i) of this AD 
is accomplished.

    Note 1: For the purposes of this AD, a detailed inspection is: 
``An intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirror, magnifying

[[Page 72604]]

lenses, etc., may be necessary. Surface cleaning and elaborate 
procedures may be required.''

Corrective Actions

    (h) If any crack is found during any inspection required by this 
AD, do the applicable action in paragraph (h)(1), (h)(2), or (h)(3) 
of this AD.
    (1) If the crack is in the pocket area and the crack is within 
the trim-out limits specified in McDonnell Douglas Service Sketch 
3529, dated August 23, 1983: Repeat the inspection specified in 
paragraph (g) of this AD at intervals not to exceed 3,400 flight 
hours until the action in paragraph (i) of this AD is accomplished.
    (2) If the crack is in the pocket area and the crack exceeds the 
trim-out limits specified in McDonnell Douglas Service Sketch 3529, 
dated August 23, 1983, before further flight: Do the action in 
paragraph (i) of this AD.
    (3) If the crack is in the web, before further flight: Do the 
action in paragraph (i) of this AD.

Optional Terminating Action

    (i) Replacing the frame with a new or serviceable frame made of 
7075-T73 aluminum material in accordance with the service bulletin 
terminates the repetitive inspection requirements of this AD for 
that frame only.

No Reporting Required

    (j) Although the service bulletin referenced in this AD 
specifies to submit certain information to the manufacturer, this AD 
does not include that requirement.

Parts Installation

    (k) After the effective date of this AD, no person may install 
on any airplane a frame made of 7075-T6 aluminum material.

Alternative Methods of Compliance (AMOCs)

    (l) The Manager, Los Angeles Aircraft Certification Office 
(ACO), FAA, has the authority to approve AMOCs for this AD, if 
requested in accordance with the procedures found in 14 CFR 39.19.

    Issued in Renton, Washington, on November 25, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-23655 Filed 12-5-05; 8:45 am]
BILLING CODE 4910-13-P