[Federal Register: May 9, 2005 (Volume 70, Number 88)]
[Proposed Rules]
[Page 24338-24341]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09my05-19]
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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.
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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
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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 4 to 6............. $65 None............... $260 to 390............. 426 $110,760 to $166,140, per
cycle. inspection cycle.
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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
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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.
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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