[Federal Register Volume 70, Number 88 (Monday, May 9, 2005)]
[Proposed Rules]
[Pages 24338-24341]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-9188]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21140; Directorate Identifier 2004-NM-274-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-14, DC-9-
15, and DC-9-15F Airplanes; and McDonnell Douglas Model 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 all transport category airplanes listed above. This proposed AD 
would require repetitive inspections for cracks of the main landing 
gear (MLG) shock strut cylinder, and related investigative and 
corrective actions if necessary. This proposed AD is prompted by two 
reports of a collapsed MLG and a report of cracks in two MLG cylinders. 
We are proposing this AD to detect and correct fatigue cracks in the 
shock strut cylinder of the MLG, which could result in a collapsed MLG 
during takeoff or landing, and possible reduced structural integrity of 
the airplane.

DATES: We must receive comments on this proposed AD by June 23, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     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.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood 
Boulevard, Long Beach, California 90846, Attention: Data and Service 
Management, Dept. C1-L5A (D800-0024).
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-
401, on the plaza level of the Nassif Building, Washington, DC. This 
docket number is FAA-2005-21140; the directorate identifier for this 
docket is 2004-NM-274-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. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-21140; 
Directorate Identifier 2004-NM-274-AD'' in the subject line 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 submitted 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 website, 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 can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.

Examining the Docket

    You can 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 DMS receives them.

Discussion

    We have received a report of two incidents of a collapsed main 
landing gear (MLG) on one McDonnell Douglas Model DC-9-32 airplane and 
one Model DC-9-31 airplane. These incidents happened when the MLG 
cylinder cracked and failed. The cracks and failures were caused by 
fatigue stresses from inclusions in high-stress areas, which caused 
sub-surface fatigue cracks to propagate to the surface of the MLG 
cylinder. After the two failures, the airplane operator started an 
inspection program and found cracks in two additional cylinders before 
the cracks

[[Page 24339]]

grew large enough to cause an MLG failure. These additional cracks were 
found on one McDonnell Douglas Model DC-9-14 airplane and one Model DC-
9-15 airplane. Laboratory testing and failure analysis confirmed that 
inclusions and sub-surface fatigue cracks were present in all four 
cases, at the same location. This condition, if not corrected, could 
result in a collapsed MLG during takeoff or landing, and possible 
reduced structural integrity of the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin DC9-32A350, dated 
December 3, 2004. The service bulletin gives procedures for verifying 
the number of landings on the MLG shock strut cylinder by examining 
each airplane's service history. For airplanes that have less than 
60,000 landings on the MLG, the service bulletin states that no further 
action is required until the MLG reaches the 60,000-landing threshold.
    The service bulletin also gives procedures for reviewing the 
maintenance records to determine if the MLG shock strut cylinders on 
airplanes identified in the service bulletin as Group 3 have always 
been on Group 3 airplanes.
    The service bulletin gives two inspection options:
     Option 1: Fluorescent dye penetrant inspection combined 
with fluorescent magnetic particle inspection.
     Option 2: Phased array ultrasonic inspection.
    For MLG shock strut cylinders on which no crack indication is 
found, the service bulletin gives procedures for repeating the 
inspections.
    For MLG shock strut cylinders on which any crack indication is 
found during any inspection, the service bulletin recommends related 
investigative and corrective actions. The related investigative and 
corrective actions vary according to the inspection option and are 
described in the table below.

                       Related Investigative and Corrective Actions for Crack Indications
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                     Inspect to confirm                                               If crack indication not
                     crack indication--       If crack indication confirmed--               confirmed--
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Option 1..........  Remove the cadmium    Replace the shock strut cylinder and     Apply the primer and topcoat,
                     plating and repeat    repeat either the Option 1 or Option 2   and repeat either the Option
                     the Option 1          inspection at the applicable interval    1 or Option 2 inspection at
                     inspection to         indicated in the service bulletin.       the applicable interval
                     confirm the crack.                                             indicated in the service
                                                                                    bulletin.
Option 2..........  Remove the primer     Remove the cadmium plating and repeat    Apply the primer and topcoat
                     and topcoat and       the Option 2 inspection to re-confirm    and repeat either the Option
                     repeat the Option 2   the crack indication.                    1 or Option 2 inspection at
                     inspection to        If the crack indication is re-            the applicable interval
                     confirm the crack.    confirmed, replace the shock strut       indicated in the service
                                           cylinder and repeat either the Option    bulletin.
                                           1 or Option 2 inspection at the
                                           applicable interval indicated in the
                                           service bulletin.
----------------------------------------------------------------------------------------------------------------

    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. Therefore, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
bulletin described previously.

Costs of Compliance

    There are about 644 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
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                   Number of
                                                        Average                                                      U.S.-
             Action                   Work hours       labor rate         Parts             Cost per airplane     registered          Fleet cost
                                                        per hour                                                   airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection, per inspection       4 to 6.............          $65  None...............  $260 to 390.............         426  $110,760 to $166,140, per
 cycle.                                                                                                                        inspection cycle.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Explanation of Change to Applicability

    We have specified model designations in the applicability of this 
proposed AD as published in the most recent type certificate data sheet 
for the affected models. These model designations do not include the 
DC-9-10 and DC-9-33, which are listed in paragraph 1.A. 
``Effectivity,'' of the referenced service bulletin.

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.

[[Page 24340]]

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 
proposedregulation:
    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. 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 FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

McDonnell Douglas: Docket No. FAA-2005-21140; Directorate Identifier 
2004-NM-274-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by June 23, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all McDonnell Douglas Model DC-9-14, DC-
9-15, and DC-9-15F airplanes; Model DC-9-21 airplanes; Model DC-9-
31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-33F, DC-9-34, DC-9-34F, 
and DC-9-32F (C-9A, C-9B) airplanes; Model DC-9-41 airplanes; and 
Model DC-9-51 airplanes; certificated in any category.

Unsafe Condition

    (d) This AD was prompted by two reports of a collapsed main 
landing gear (MLG) and a report of cracks in two MLG cylinders. We 
are issuing this AD to detect and correct fatigue cracks in the 
shock strut cylinder of the MLG, which could result in a collapsed 
MLG during takeoff or landing, and possible 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 Paragraph

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing Alert Service Bulletin DC9-
32A350, dated December 3, 2004.

Records Review

    (g) Before the applicable compliance time specified in paragraph 
(h) or Table 1 of this AD, as applicable, do the applicable actions 
in paragraphs (g)(1) and (g)(2) of this AD.
    (1) For all airplane groups: Review the airplane maintenance 
records of the MLG to determine its service history and the number 
of landings on the MLG shock strut cylinder.
    (2) For Group 3 airplanes identified in the service bulletin: 
Review the maintenance records to determine if the MLG cylinder on 
each Group 3 airplane has always been on a Group 3 airplane, and do 
the actions in paragraph (k) of this AD.

Inspection

    (h) Inspect the MLG shock strut cylinders for cracks using the 
Option 1 or Option 2 non-destructive testing inspection described in 
the service bulletin. Inspect in accordance with the Accomplishment 
Instructions of the service bulletin. Do the detailed inspection 
before the accumulation of 60,000 total landings on the MLG, or at 
the applicable grace period specified in Table 1 of this AD, 
whichever occurs later, except as provided by paragraph (k) of this 
AD. If the review of maintenance records is not sufficient to 
conclusively determine the service history and number of landings on 
the MLG shock strut cylinder, perform the initial inspection at the 
applicable grace period specified in Table 1 of this AD.

                                 Table 1.--Grace Period and Repetitive Interval
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  Airplanes identified in the service
           bulletin as group                             Grace period                     Repetitive interval
----------------------------------------------------------------------------------------------------------------
1.....................................  Within 18 months or 650 landings after the     Intervals not to exceed
                                         effective date of this AD, whichever occurs    650 landings.
                                         first.
2.....................................  Within 18 months or 500 landings after the     Intervals not to exceed
                                         effective date of this AD, whichever occurs    500 landings.
                                         first.
3, except as provided by paragraph (k)  Within 18 months or 2,500 landings after the   Intervals not to exceed
 of this AD.                             effective date of this AD, whichever occurs    2,500 landings.
                                         first.
4.....................................  Within 18 months or 2,100 landings after the   Intervals not to exceed
                                         effective date of this AD, whichever occurs    2,100 landings.
                                         first.
----------------------------------------------------------------------------------------------------------------

No Crack Indication Found

    (i) If no crack indication is found during the inspection 
required by paragraph (h) of this AD, repeat the inspection at the 
applicable interval specified in Table 1 of this AD.

Related Investigative and Corrective Actions

    (j) If any crack indication is found during any inspection 
required by paragraph (h) or (i) of this AD, before further flight: 
Confirm the crack indication by doing all applicable related 
investigative actions and doing the applicable corrective actions in 
accordance with the service bulletin. Repeat the inspection at the 
applicable threshold and interval specified in paragraph (h) of this 
AD.

MLG Cylinder Previously Installed on Group 4 Airplanes

    (k) For MLG cylinders on Group 3 airplanes as identified in the 
service bulletin: If the MLG cylinder was previously installed on a 
Group 4 airplane, as identified in the service bulletin, or if the 
service history and number of landings cannot be determined, the MLG 
cylinder must be inspected at the grace period and repetitive 
interval that applies to Group 4 airplanes, as specified in Table 1 
of this AD.

Alternative Methods of Compliance (AMOCs)

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


[[Page 24341]]


    Issued in Renton, Washington, on April 29, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-9188 Filed 5-6-05; 8:45 am]
BILLING CODE 4910-13-P