[Federal Register Volume 68, Number 198 (Tuesday, October 14, 2003)]
[Proposed Rules]
[Pages 59139-59143]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-25868]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-275-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-90-30 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain McDonnell Douglas 
Model MD-90-30

[[Page 59140]]

airplanes, that currently requires repetitive fluorescent penetrant and 
magnetic particle inspections to detect fatigue cracking of the main 
landing gear (MLG) piston, and repair if necessary. This action would 
expand the applicability of the existing AD to require the currently 
required inspections, and corrective actions if necessary, on 
additional airplanes and MLG piston part numbers, and would require 
repetitive inspections for evidence of cracking in the paint topcoat of 
the MLG pistons. This action also would require replacement of certain 
MLG shock strut piston assemblies with new or serviceable improved 
assemblies, which would terminate the requirements of this AD. These 
actions are necessary to prevent fatigue cracking of MLG pistons, which 
could result in failure of the pistons, and consequent damage to the 
airplane structure and injury to flightcrew, passengers, or ground 
personnel. These actions are intended to address the identified unsafe 
condition.

DATES: Comments must be received by November 28, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-275-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-275-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 or 2000 or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Aircraft Group, Long Beach Division, 
3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data 
and Service Management, Dept. C1-L5A (D800-0024). This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Carl Fountain, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5222; 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-275-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. 2001-NM-275-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On February 8, 2000, the FAA issued AD 2000-03-08, amendment 39-
11567 (65 FR 7719, February 16, 2000), applicable to certain McDonnell 
Douglas Model MD-90-30 airplanes, to require repetitive fluorescent 
penetrant and magnetic particle inspections to detect fatigue cracking 
of the main landing gear (MLG) piston, and repair if necessary. That 
action was prompted by reports that, during towing of in-service 
airplanes, MLG failures occurred due to fatigue cracks. The 
requirements of that AD are intended to detect and correct fatigue 
cracking of MLG pistons, which could result in failure of the pistons, 
and consequent damage to the airplane structure and injury to 
flightcrew, passengers, or ground personnel.
    In the preamble to AD 2000-03-08, we specified that the actions 
required by that AD were considered ``interim action'' and that the 
manufacturer was developing a modification to address the unsafe 
condition. We indicated that we might consider further rulemaking 
action once the modification was developed, approved, and available. 
The manufacturer now has developed such a modification, and we have 
determined that further rulemaking action is indeed necessary. This 
proposed AD follows from that determination.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 2000-03-08, we have issued AD 2002-10-03, 
amendment 39-12749 (67 FR 34823), which applies to certain McDonnell 
Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-
87 (MD-87), MD-88, and MD-90-30 airplanes. For Model MD-90-30 
airplanes, that AD requires replacement of certain MLG shock strut 
piston assemblies with new or serviceable improved assemblies, 
according to Boeing Service Bulletin MD90-32-031, Revision 01, dated 
April 25, 2001. Accomplishment of that replacement will terminate the 
requirements of this AD, as noted in paragraph (b) of AD 2002-10-03. 
Therefore, we have included in paragraph (j) of this proposed AD the 
requirements of paragraph (a) of AD 2002-10-03 that apply to the Model 
MD-90-30 airplanes subject to this proposed AD. The compliance time for 
the replacement specified in this proposed AD (``Before the 
accumulation of 30,000 total landings on the MLG shock strut piston 
assemblies, or within 5,000 landings after June 20, 2002 (the effective 
date of AD 2002-10-03, amendment 39-12749), whichever occurs later'') 
is the same as the compliance time in paragraph (a) of AD 2002-10-03. 
Once this proposed AD becomes effective, we may consider further 
rulemaking to revise or rescind AD 2002-10-03 to remove the duplicate 
requirement.

[[Page 59141]]

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Service Bulletin MD90-32-012, 
Revision 03, dated June 29, 2001. (AD 2000-03-08 refers to Boeing 
Service Bulletin MD90-32-012, Revision 01, dated June 2, 1998, as the 
acceptable source of service information for the actions required by 
that AD. Also, the applicability statement of AD 2000-03-08 states that 
the AD applies to Model MD-90-30 airplanes as listed in Boeing Service 
Bulletin MD90-32-012, Revision 01). Revision 03 of the service bulletin 
is also effective for additional airplanes and MLG piston part numbers 
that were not included in Revision 01 of the service bulletin. Revision 
03 describes procedures for initial fluorescent penetrant and magnetic 
particle inspections to detect cracking of the MLG torque link lugs; 
follow-on repetitive visual, fluorescent penetrant, and magnetic 
particle inspections for cracking of the MLG torque link lugs; and 
repetitive visual inspections for evidence of cracking in the paint 
topcoat, and, if any evidence of cracking in the paint topcoat is 
found, a follow-on NDT inspection of the MLG piston to determine if any 
cracking is present. Revision 03 of the service bulletin specifies to 
contact Boeing for repair instructions if any crack is found.
    As explained previously in the preamble of the notice of proposed 
rulemaking (NPRM) for AD 2002-10-03, the FAA has reviewed and approved 
Boeing Service Bulletin MD90-32-031, Revision 01. That service bulletin 
describes procedures for replacement of the MLG shock strut piston 
assemblies, left and right-hand side, with new or serviceable, improved 
assemblies, which would eliminate the need for the repetitive 
inspections described above.
    Accomplishment of the actions specified in the service bulletins 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 supersede AD 2000-03-08 to continue to require 
repetitive fluorescent penetrant and magnetic particle inspections to 
detect fatigue cracking of the MLG piston, and repair if necessary. The 
proposed AD would expand the applicability of the existing AD to 
include additional airplanes and MLG piston part numbers. These actions 
would be required to be accomplished per Boeing Service Bulletin MD90-
32-012, Revision 03, which was described previously, except as 
discussed below under the heading ``Differences Between Proposed AD and 
Service Bulletin.'' The proposed AD also would require replacement of 
certain MLG shock strut piston assemblies with new or serviceable 
improved assemblies, which would terminate the existing requirements of 
this proposed AD. This action would be required to be accomplished per 
Boeing Service Bulletin MD90-32-031, Revision 01.
    Operators may note that, consistent with the provisions of Boeing 
Service Bulletin MD90-32-012, Revision 03, if any evidence of cracking 
in the paint topcoat of the MLG piston is found, the proposed AD would 
allow deferral, for the earlier of 7 days or 50 landings, of the 
follow-on NDT inspection to detect any cracking of the MLG piston. We 
have determined that, for this proposed AD, such a deferral would not 
adversely affect the continued operating safety of an affected 
airplane. Accomplishment of the NDT inspection for cracking of the MLG 
piston, and any necessary repair, within 7 days or 50 landings after 
evidence of cracking in the topcoat paint is found, would adequately 
ensure that any cracking of the MLG piston would be detected before it 
represents a hazard to the airplane.

Differences Between Proposed AD and Service Bulletin

    Although Boeing Service Bulletin MD90-32-012, Revision 03, 
describes procedures for fluorescent penetrant and magnetic particle 
inspections, that service bulletin does not emphasize the sequence of 
these inspections. We find that, in each inspection cycle, it is 
necessary for the fluorescent penetrant inspection to precede the 
magnetic particle inspection. This sequencing is important because we 
are aware of cases in which accomplishment of a magnetic particle 
inspection before a fluorescent penetrant inspection interfered with 
the results of the fluorescent penetrant inspection. Therefore, 
paragraph (e) has been included in this proposed AD to clarify that, 
for inspections performed after the effective date of this AD, 
accomplishment of the fluorescent penetrant inspection must precede 
accomplishment of the magnetic particle inspection.
    Operators should note that, although Boeing Service Bulletin MD90-
32-012, Revision 03, specifies that the manufacturer may be contacted 
for disposition of repair conditions, this proposed AD would require 
repairs to be accomplished per a method approved by the FAA.

Cost Impact

    There are approximately 114 Model MD-90-30 airplanes of the 
affected design in the worldwide fleet.
    In AD 2000-03-08, we estimated that the actions in that AD applied 
to 15 airplanes of U.S. registry. The actions that are currently 
required by AD 2000-03-08 take approximately 2 work hours per airplane 
to accomplish, at an average labor rate of $65 per work hour. Based on 
these figures, the cost impact of the currently required actions on 
U.S. operators is estimated to be $1,950, or $130 per airplane, per 
inspection cycle.
    The FAA estimates that 21 airplanes of U.S. registry would be 
affected by this new proposed AD.
    The new inspections that are proposed in this AD action would take 
approximately 2 work hours per airplane to accomplish, at an average 
labor rate of $65 per work hour. Based on these figures, the cost 
impact of the proposed requirements of this AD on U.S. operators is 
estimated to be $2,730, or $130 per airplane.
    As explained previously, the replacement of MLG pistons that is 
included in this proposed AD is already required by AD 2002-10-03. 
Therefore, this proposed AD would add no new costs associated with that 
action. We restate the cost impact estimate in its entirety in this 
proposed AD for the convenience of affected operators:
    The replacement that is included in this AD action and currently 
required by AD 2002-10-03 takes approximately 28 work hours per 
airplane to accomplish, at an average labor rate of $65 per work hour. 
Required parts cost approximately $263,438 per airplane. Based on these 
figures, the cost impact of this requirement on U.S. operators of 
airplanes subject to this proposed AD is estimated to be $5,570,418, or 
$265,258 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted. The cost 
impact figures discussed in AD rulemaking actions represent only the 
time necessary to perform the specific actions actually required by the 
AD. These figures typically do not include incidental costs, such as 
the time required to gain access and close up, planning time, or time 
necessitated by other administrative actions. The manufacturer may 
cover the cost of replacement parts associated with this proposed AD, 
subject to warranty conditions. As a result, the costs

[[Page 59142]]

attributable to the proposed AD may be less than stated above.

Regulatory Impact

    The regulations proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 removing amendment 39-11567 (65 FR 
7719, February 16, 2000), and by adding a new airworthiness directive 
(AD), to read as follows:

McDonnell Douglas: Docket 2001-NM-275-AD. Supersedes AD 2000-03-08, 
Amendment 39-11567.

    Applicability: Model MD-90-30 airplanes listed in Boeing Service 
Bulletin MD90-32-012, Revision 03, dated June 29, 2001; certificated 
in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue cracking of main landing gear (MLG) pistons, 
which could result in failure of the pistons, and consequent damage 
to the airplane structure and injury to flightcrew, passengers, or 
ground personnel, accomplish the following:

Restatement of Requirements of AD 2000-03-08

Inspection of MLG Piston Part Number 5935347-509

    (a) For airplanes listed in McDonnell Douglas Service Bulletin 
MD90-32-012, Revision 01, dated June 2, 1998: For MLG pistons, part 
number (P/N) 5935347-509, perform fluorescent penetrant and magnetic 
particle inspections to detect fatigue cracking of the MLG pistons, 
in accordance with McDonnell Douglas Service Bulletin MD90-32-012, 
dated May 19, 1997, or Revision 01, dated June 2, 1998; or Boeing 
Service Bulletin MD90-32-012, Revision 03, dated June 29, 2001; at 
the later of the times specified in paragraphs (a)(1) and (a)(2) of 
this AD. Repeat the inspections thereafter at intervals not to 
exceed 2,500 landings.
    (1) Prior to the accumulation of 4,000 total landings; or
    (2) Within 2,500 landings or 12 months after March 22, 2000 (the 
effective date of AD 2000-03-08, amendment 39-11567), whichever is 
first.

Inspection of MLG Piston Part Numbers 5935347-511 and -513

    (b) For airplanes listed in McDonnell Douglas Service Bulletin 
MD90-32-012, Revision 01, dated June 2, 1998: For MLG pistons, P/Ns 
5935347-511 and -513, within 5,000 landings after March 22, 2000, 
perform fluorescent penetrant and magnetic particle inspections to 
detect fatigue cracking of the MLG pistons, in accordance with 
McDonnell Douglas Service Bulletin MD90-32-012, dated May 19, 1997, 
or Revision 01, dated June 2, 1998; or Boeing Service Bulletin MD90-
32-012, Revision 03, dated June 29, 2001. Repeat the inspections 
thereafter at intervals not to exceed 5,000 landings.

Repair

    (c) If any crack is found during any inspection required by 
paragraphs (a), (b), or (f) of this AD: Repair in accordance with a 
method approved by the Manager, Los Angeles Aircraft Certification 
Office (ACO), FAA. For a repair method to be approved by the 
Manager, Los Angeles ACO, as required by this paragraph, the 
Manager's approval letter must specifically refer to this AD.

New Requirements of This AD

No Requirement To Submit Information

    (d) Although Boeing Service Bulletin MD90-32-012, Revision 03, 
dated June 29, 2001, specifies to submit information to the 
manufacturer, this AD does not include such a requirement.

Clarification of Inspection Sequence

    (e) For inspections accomplished after the effective date of 
this AD: Where this AD requires fluorescent penetrant and magnetic 
particle inspections, accomplishment of the fluorescent penetrant 
inspection must precede accomplishment of the magnetic particle 
inspection.

Inspection of MLG Piston P/Ns 5935347-1 through -509, -511, and -
513; and SR09320081-3 through -13

    (f) For any MLG piston having P/N 5935347-1 through -509, -511, 
or -513; or P/Ns SR09320081-3 through -13: Perform fluorescent 
penetrant and magnetic particle inspections to detect fatigue 
cracking of the MLG pistons, in accordance with Boeing Service 
Bulletin MD90-32-012, Revision 03, dated June 29, 2001. Do the 
initial inspections at the later of the times specified in 
paragraphs (f)(1) and (f)(2) of this AD, except as provided by 
paragraph (g) of this AD. Repeat the inspections thereafter at 
intervals not to exceed 5,000 landings.
    (1) Prior to the accumulation of 4,000 total landings; or
    (2) Within 2,500 landings or 12 months after the effective date 
of this AD, whichever is first.

MLG Pistons Inspected Per Paragraph (a) or (b) of This AD

    (g) MLG pistons having P/N 5935347-509, -511, or -513 that have 
been inspected as required by paragraph (a) or (b) of this AD, as 
applicable, are not required to be reinspected per paragraph (f) of 
this AD.

Repetitive Inspections for Evidence of Cracking and Follow-on 
Actions

    (h) During the first brake change after the effective date of 
this AD, perform a general visual inspection to find evidence of 
cracking in the paint topcoat of the MLG piston, per the 
Accomplishment Instructions of Boeing Service Bulletin MD90-32-012, 
Revision 03, dated June 29, 2001. Repeat this inspection during 
every brake change.
    (1) If any evidence of cracking in the paint topcoat, as 
described in the service bulletin, is found: Within 7 days or 50 
landings after the evidence is found, whichever is first, perform a 
non-destructive test (NDT) inspection of the MLG piston to determine 
if there is any cracking.
    (2) If any crack is found during the NDT inspection required by 
paragraph (h)(1) of this AD, before further flight, repair per a 
method approved by the Manager, Los Angeles ACO. For a repair method 
to be approved by the Manager, Los Angeles ACO, as required by this 
paragraph, the Manager's approval letter must specifically refer to 
this AD.

    Note 1: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''


[[Page 59143]]



Inspections Accomplished Per Previous Issue of Service Bulletin

    (i) Inspections accomplished before the effective date of this 
AD per McDonnell Douglas Service Bulletin MD90-32-012, Revision 02, 
dated June 29, 1999, are considered acceptable for compliance with 
the corresponding action specified in this AD.

Replacement of MLG Shock Strut Piston Assemblies

    (j) Before the accumulation of 30,000 total landings on the MLG 
shock strut piston assemblies, or within 5,000 landings after June 
20, 2002 (the effective date of AD 2002-10-03, amendment 39-12749), 
whichever occurs later: Replace the MLG shock strut piston 
assemblies, left- and right-hand sides, with new or serviceable 
improved assemblies, per the Accomplishment Instructions of Boeing 
Service Bulletin MD90-32-031, Revision 01, dated April 25, 2001. If 
the MLG shock strut piston is not serialized or the number of 
landings on the piston cannot be conclusively determined, consider 
the total number of landings on the piston assembly to be equal to 
the total number of landings accumulated by the airplane with the 
highest total number of landings in the operator's fleet.

    Note 2: Paragraph (a) of AD 2002-10-03, amendment 39-12749, 
requires the same actions as paragraph (j) of this AD.

Compliance With Requirements of Other ADs

    (k) Accomplishment of the replacement required by paragraph (j) 
of this AD constitutes terminating action for the requirements of 
this AD and AD 2002-10-03, amendment 39-12749, for the Model MD-90-
30 airplanes listed in Boeing Service Bulletin MD90-32-012, Revision 
03, dated June 29, 2001.

Alternative Methods of Compliance

    (l)(1) In accordance with 14 CFR 39.19, the Manager, Los Angeles 
ACO, is authorized to approve alternative methods of compliance for 
this AD.
    (2) Alternative methods of compliance, approved previously per 
AD 2000-03-08, amendment 39-11567, are approved as alternative 
methods of compliance with paragraphs (a), (b), and (c) of this AD.

    Issued in Renton, Washington, on October 7, 2003.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-25868 Filed 10-10-03; 8:45 am]
BILLING CODE 4910-13-P