[Federal Register Volume 65, Number 193 (Wednesday, October 4, 2000)]
[Proposed Rules]
[Pages 59146-59150]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-25434]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 65, No. 193 / Wednesday, October 4, 2000 / 
Proposed Rules  

[[Page 59146]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-164-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series 
Airplanes and Model MD-88 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain McDonnell Douglas 
Model DC-9-80 series airplanes and Model MD-88 airplanes, that 
currently requires a one-time inspection to detect cracking of the main 
landing gear (MLG) pistons, and repair or replacement of the pistons 
with new or serviceable parts, if necessary. This action would require, 
among other actions, repetitive dye penetrant and magnetic particle 
inspections to detect cracks of the MLG pistons; repair and replacement 
of discrepant parts; and installation of a preventative modification; 
as applicable. This action also would provide for an optional 
terminating action for certain MLG pistons. This proposal is prompted 
by additional reports of failure of the MLG pistons during towing of 
the airplanes. The actions specified by the proposed AD are intended to 
prevent fatigue cracking of the MLG pistons, which could result in 
failure of the pistons and subsequent damage to the airplane structure 
or injury to airplane occupants.

DATES: Comments must be received by November 20, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-164-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. 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. 99-NM-164-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 for Windows 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: 
Technical Publications Business Administration, Dept. 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, 
Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Brent Bandley, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(310) 627-5237; fax (310) 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.
    Submit comments using the following format:
     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.
     For each issue, state what specific change to the proposed 
AD is being requested.
     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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-164-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. 99-NM-164-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On September 5, 1996, the FAA issued AD 96-19-09, amendment 39-9756 
(61 FR 48617, September 16, 1996), applicable to certain McDonnell 
Douglas Model DC-9-80 series airplanes and Model MD-88 airplanes, to 
require a one-time inspection to detect cracking of the main landing 
gear (MLG) pistons, and repair or replacement of the pistons with new 
or serviceable parts, if necessary. That action was prompted by reports 
of failure of the MLG pistons that occurred during towing of the 
airplanes. The requirements of that AD are intended to prevent fatigue 
cracking of the MLG pistons, which could result in failure of the 
pistons and subsequent damage to the airplane structure or injury to 
airplane occupants.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 96-19-09, the FAA has received additional 
reports of cracked MLG pistons on the affected airplanes. The FAA has 
determined that the one-time inspection of the MLG

[[Page 59147]]

pistons required by AD 96-19-09 does not adequately preclude fatigue 
cracking of the MLG pistons. Also, Boeing has completed its assessment 
to establish a life limit for the MLG pistons affected by this AD.

Explanation of Relevant Service Information

    The manufacturer issued, and the FAA reviewed and approved, 
McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated 
December 7, 1999. The service bulletin describes a new life limit 
(i.e., 30,000 or 60,000 total landings, as applicable) for the affected 
MLG pistons. The service bulletin also describes the following improved 
procedures for the affected airplanes depending on the configuration:
     Performing repetitive dye penetrant and magnetic particle 
inspections to detect cracks of the MLG pistons. And
     Performing a preventative modification that involves 
various inspections to detect cracks of the MLG pistons; repair and 
replacement of discrepant parts, as applicable; wet grinding the rework 
area; flap shot peening the rework area; and reidentifying the MLG 
pistons. Accomplishment of the preventative modification stops the 
repetitive dye penetrant and magnetic particle inspections. And
     Flap shot peening, replacing the MLG piston with a new or 
serviceable MLG piston, and contacting Boeing for certain conditions.

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 96-19-09 to require accomplishment of 
the actions specified in the service bulletin described previously, 
except as described below.

Error in Referenced Service Bulletin

    For Group 1 airplanes, the referenced service bulletin incorrectly 
refers to paragraph 1.E. for the repetitive inspection schedule for 
Condition 3, Option 1 of the Accomplishment Instructions. Paragraph 
1.E. does not contain such a repetitive inspection schedule.

Differences Between Proposed Rule and Service Bulletin

    The effectivity listing of the referenced service bulletin lists 
the affected airplanes by groups (i.e., Group 1, Group 2, and Group 3). 
The FAA finds that Group 1 and 2 airplanes do not include all of the 
affected modified pistons. For Groups 1 and 2, the referenced service 
bulletin only refers to pistons that have been inspected, replaced, or 
modified per prior issues of the service bulletin. However, affected 
pistons may have been modified per other service documents in addition 
to previous revisions of the referenced service bulletin. Also, the FAA 
finds no need to specifically reference MLG pistons that have been 
inspected or replaced per prior issues of the service bulletin, because 
the only thing that defines Groups 1 and 2 is whether the affected 
piston has been modified. The FAA also finds that Groups 1 and 2 of the 
referenced service bulletin do not include the specific affected MLG 
pistons [i.e., part number (P/N) 5935347-1 through 5935347-509 
inclusive]. Therefore, this proposed AD references the specific 
affected MLG pistons and whether that piston has been modified, rather 
than the airplanes specified in the service bulletin.
    Operators also should note that, although the referenced service 
bulletin specifies that the manufacturer may be contacted for 
disposition of certain repair conditions, this proposed AD would 
require the repair of those conditions to be accomplished in accordance 
with a method approved by the FAA.
    The referenced service bulletin also specifies that landing gear 
pistons, modified per one of the following conditions, are acceptable 
as having complied with the intent of the service bulletin:
    1. As a result of procedure verification;
    2. As a repair per operator's inquiry and Boeing disposition; or
    3. As a preventative modification accomplished by operators who 
participated in the procedure verification prior to the issuance of 
this service bulletin revision. However, this proposed AD would require 
accomplishment of the actions in accordance with the procedures 
specified in the referenced service bulletin. Any other procedure may 
be used only if approved as an alternative method of compliance in 
accordance with paragraph (m) of this AD.
    The referenced service bulletin recommends performing repetitive 
visual inspections to detect cracks in the topcoat paint of the MLG 
piston, performing a non-destructive testing (NDT) inspection, and 
contacting Boeing, if necessary. The FAA has determined that the 
repetitive inspections of the MLG pistons and eventual preventative 
modification required by this proposed AD adequately addresses the 
identified unsafe condition for the interim. Therefore, the repetitive 
visual inspections of the topcoat paint and NDT inspection are not 
required by the proposed AD.
    For any piston having P/N 5935347-511 that has accumulated 30,000 
or more total landings, the referenced service bulletin recommends 
either replacing the MLG piston with a new or serviceable MLG piston or 
contacting Boeing. The FAA has consulted with Boeing and determined 
that any piston having P/N 5935347-511 that has accumulated 30,000 or 
more total landings must be replaced. Therefore, the proposed AD only 
requires replacement of those pistons.
    Operators also should note that, unlike the referenced service 
bulletin, the proposed AD provides for an optional terminating action 
for the requirements of the AD. The optional terminating action 
involves replacing all MLG pistons with MLG pistons having P/N 5935347-
517, which are redesigned pistons that will adequately address the 
identified unsafe condition.

Interim Action

    This is considered to be interim action. The manufacturer has 
advised that it currently is developing a replacement schedule to 
eventually remove all affected MLG pistons from the fleet and replace 
them with redesigned MLG pistons. Once this replacement schedule is 
developed, approved, and available, the FAA may consider additional 
rulemaking.

Cost Impact

    There are approximately 1,200 Model DC-9-80 series airplanes and 
Model MD-88 airplanes of the affected design in the worldwide fleet. 
The FAA estimates that 700 airplanes of U.S. registry would be affected 
by this proposed AD.
    Should an operator be required to do the dye pernetrant and 
magnetic particle inspections, it would take approximately 2 work hours 
per MLG piston to accomplish the inspections, at an average lavor rate 
of $60 per work hour. Based on thes figures, the cost impact of these 
inspections proposed by this AD on U.S. operators is estimated to be 
$120 per MLG piston.
    Should an operator be required to do the preventative 
modidfication, it would take approximately 6 work hours per MLG piston 
to accomplish the inspections, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of these inspections 
proposed by this AD on U.S.

[[Page 59148]]

operators is estimated to be $36 per MLG piston.
    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.
    Should an operator elect to accomplish the optional terminating 
action that would be provided by this AD action, it would take 
approximately 31 work hours per MLG piston to accomplish it, at an 
average labor rate of $60 per work hour. The cost of required parts 
would be approximately $107,070 per MLG piston. Based on these figures, 
the cost impact of the optional terminating action would be $108,930 
per MLG piston.

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 39-9756 (61 FR 
48617, September 16, 1996), and by adding a new airworthiness directive 
(AD), to read as follows:

McDonnell Douglas: Docket 99-NM-164-AD. Supersedes AD 96-19-09, 
Amendment 39-9756.

    Applicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 
(MD-83), and DC-9-87 (MD-87) series airplanes; and Model MD-88 
airplanes; as listed in McDonnell Douglas Service Bulletin MD80-32-
277, Revision 04, dated December 7, 1999; 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 (m)(1) 
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 main landing gear (MLG) 
pistons, which could result in failure of the pistons and subsequent 
damage to the airplane structure or injury to airplane occupants, 
accomplish the following:

For Airplanes on Which Certain Pistons Have Not Been Modified: 
Inspections

    (a) For airplanes on which any MLG piston, part number (P/N) 
5935347-1 through 5935347-509 inclusive, has NOT been modified: Do 
the actions specified in paragraph (a)(1), (a)(2), or (a)(3) of this 
AD, as applicable, per the Accomplishment Instructions of McDonnell 
Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 
1999.
    (1) For any MLG piston that has accumulated less than 5,000 
total landings since date of manufacture: Prior to the accumulation 
of 5,000 total landings on the MLG piston, or within 12 months after 
the effective date of this AD, whichever occurs later, do dye 
penetrant and magnetic particle inspections to detect cracks of the 
MLG pistons.
    (2) For any MLG piston that has accumulated 5,000 or more total 
landings since date of manufacture, but less than 30,000 total 
landings since date of manufacture: Within 1,500 landings on the MLG 
piston or 12 months after the effective date of this AD, whichever 
occurs later, do dye penetrant and magnetic particle inspections to 
detect cracks of the MLG pistons.
    (3) For any MLG piston that has accumulated 30,000 or more total 
landings since date of manufacture: Within 2 years or 5,000 landings 
on the MLG piston after the effective date of this AD, whichever 
occurs first, do the preventative modification (including 
inspections; corrective actions, if necessary; wet grind rework 
area; flap shot peen rework area; and reidentify the MLG pistons); 
except as required by paragraph (k) of this AD. Following 
accomplishment of the preventative modification, do the actions 
specified in paragraph (e) at the time indicated in that paragraph.

For Airplanes on Which Certain Pistons Have Not Been Modified: 
Condition 1 (No Crack)

    (b) If no crack is found during any inspection required by 
either paragraph (a)(1) or (a)(2) of this AD, do the actions 
specified in either paragraph (b)(1) or (b)(2) of this AD.
    (1) Condition 1, Option 1. Do the actions specified in either 
paragraph (b)(1)(i) or (b)(1)(ii) of this AD, and in paragraph 
(b)(1)(iii) of this AD.
    (i) Repeat the inspections required by either paragraph (a)(1) 
or (a)(2) of this AD thereafter at intervals not to exceed 1,500 
landings until the permanent modification required by paragraph 
(b)(1)(iii) of this AD has been done.
    (ii) Before further flight, do the flap shot peening per 
McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated 
December 7, 1999. Repeat the inspections required by either 
paragraph (a)(1) or (a)(2) of this AD thereafter at intervals not to 
exceed 2,500 landings until the permanent modification required by 
paragraph (b)(1)(iii) of this AD has been done.
    (iii) Prior to the accumulation of 30,000 or more total landings 
on the MLG piston, do the preventative modification (including 
inspections; corrective actions, if necessary; wet grind rework 
area; flap shot peen rework area; and reidentify the MLG pistons), 
per the Accomplishment Instructions of McDonnell Douglas Service 
Bulletin MD80-32-277, Revision 04, dated December 7, 1999; except as 
required by paragraph (k) of this AD. Accomplishment of the 
permanent modification stops the repetitive inspection requirements 
of paragraphs (b)(1)(i) and (b)(1)(ii) of this AD. Following 
accomplishment of the preventative modification, do the actions 
specified in paragraph (e) at the time indicated in that paragraph.
    (2) Condition 1, Option 2. Before further flight, do the 
preventative modification (including inspections; corrective 
actions, if necessary; wet grind rework area; flap shot peen rework 
area; and reidentify the MLG pistons) per Condition 1, Option 2, of 
the Accomplishment Instructions of McDonnell

[[Page 59149]]

Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 
1999; except as required by paragraph (k) of this AD. Following 
accomplishment of the preventative modification, do the actions 
specified in paragraph (e) at the time indicated in that paragraph.

For Airplanes on Which Certain Pistons Have Not Been Modified: 
Condition 2 (Any Crack Within Limits)

    (c) If any crack is found during any inspection required by 
either paragraph (a)(1) or (a)(2) of this AD, and that crack is 
within the limits specified in McDonnell Douglas Service Bulletin 
MD80-32-277, Revision 04, dated December 7, 1999, before further 
flight, do the action(s) specified in either paragraph (c)(1) or 
(c)(2) of this AD.
    (1) Do the preventative modification (including inspections; 
corrective actions, if necessary; wet grind rework area; flap shot 
peen rework area; and reidentify the MLG pistons) per the 
Accomplishment Instructions of the service bulletin; except as 
required by paragraph (k) of this AD. Following accomplishment of 
the preventative modification, do the actions specified in paragraph 
(e) or (h) of this AD, as applicable, at the time indicated in that 
paragraph.
    (2) Replace the MLG piston with a new or serviceable MLG piston 
per the service bulletin. Following accomplishment of the 
replacement, do the actions specified in paragraph (a), (e), or (h) 
of this AD, as applicable, at the time indicated in that paragraph.

For Airplanes on Which Certain Pistons Have Not Been Modified: 
Condition 3 (Any Crack Outside Limits)

    (d) If any crack is found during any inspection required by 
either paragraph (a)(1) or (a)(2) of this AD that is outside the 
limits specified in McDonnell Douglas Service Bulletin MD80-32-277, 
Revision 04, dated December 7, 1999, before further flight, do the 
action(s) specified in paragraph (d)(1) or (d)(2) of this AD.
    (1) Condition 3, Option 1. Replace the MLG piston with a new or 
serviceable MLG piston per the service bulletin. Following 
accomplishment of the replacement, do the actions specified in 
paragraph (a), (e), or (h) of this AD, as applicable, at the time 
indicated in that paragraph.
    (2) Condition 3, Option 2. Repair per a method approved by the 
Manager, Los Angeles Aircraft Certification Office (ACO), FAA.

For Airplanes on Which Certain Pistons Have Been Modified: Replacement 
or Inspections and Corrective Actions, If Necessary

    (e) For airplanes on which any MLG piston, part number (P/N) 
5935347-1 through 5935347-509 inclusive, has been modified:
    (1) For any MLG piston that has accumulated 30,000 or more 
landings since accomplishment of the modification: Within 6 months 
after the effective date of this AD, replace the MLG piston with a 
new or serviceable MLG piston per the service bulletin. Following 
accomplishment of the replacement, do the actions specified in 
paragraph (a), (e), or (h) of this AD, as applicable, at the time 
indicated in that paragraph.
    (2) For any MLG piston that has accumulated less than 30,000 
landings since accomplishment of the modification: Do dye penetrant 
and magnetic particle inspections to detect cracks of the MLG 
pistons, per the Accomplishment Instructions of McDonnell Douglas 
Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999; 
at the applicable time(s) specified in paragraph (e)(2)(i) or 
(e)(2)(ii) of this AD.
    (i) For any MLG piston that has been modified per paragraph 
(a)(3), (b)(1)(iii), (b)(2), or (c)(1) of this AD, or that has been 
replaced with a modified MLG piston per paragraph (c)(2) or (d)(1) 
of this AD: Inspect within 2,500 landings following accomplishment 
of the modification or replacement with a modified MLG piston.
    (ii) For any MLG piston that has been modified prior to the 
effective date of this AD: Inspect within 1,500 landings or 12 
months after the effective date of this AD, whichever occurs later.
    (f) If no crack is found during any inspection required by 
paragraph (e)(2) of this AD, repeat the dye penetrant and magnetic 
particle inspections required by paragraph (e)(2) of this AD 
thereafter at intervals not to exceed 2,500 landings. Prior to the 
accumulation of 30,000 or more total landings on the MLG piston, 
replace the MLG piston with a new or serviceable MLG piston per the 
Accomplishment Instructions of McDonnell Douglas Service Bulletin 
MD80-32-277, Revision 04, dated December 7, 1999. Following 
accomplishment of the replacement, do the actions specified in 
paragraph (a), (e), or (h) of this AD, as applicable, at the time 
indicated in that paragraph.
    (g) If any crack is found during any inspection required by 
paragraph (e)(2) of this AD, before further flight, do the action(s) 
specified in either paragraph (d)(1) or (d)(2) of this AD.

For Airplanes on Which a Certain Piston Has Been Installed

    (h) For airplanes on which any MLG piston, P/N 5935347-511, has 
been installed: Do the actions specified in paragraph (h)(1), 
(h)(2), or (h)(3) of this AD, as applicable, per the Accomplishment 
Instructions of McDonnell Douglas Service Bulletin MD80-32-277, 
Revision 04, dated December 7, 1999.
    (1) For any MLG piston that has accumulated less than 5,000 
total landings since date of manufacture: Prior to the accumulation 
of 5,000 total landings on the MLG piston, or within 12 months after 
the effective date of this AD, whichever occurs later, do dye 
penetrant and magnetic particle inspections to detect cracks of the 
MLG pistons.
    (2) For any MLG piston that has accumulated 5,000 or more total 
landings since date of manufacture, but less than 30,000 total 
landings since date of manufacture: Within 1,500 landings on the MLG 
piston or 12 months after the effective date of this AD, whichever 
occurs later, do dye penetrant and magnetic particle inspections to 
detect cracks of the MLG pistons.
    (3) For any MLG piston that has accumulated 30,000 or more total 
landings since date of manufacture: Within 6 months after the 
effective date of this AD, replace the MLG piston with a new or 
serviceable MLG piston per the service bulletin. Following 
accomplishment of the replacement, do the actions specified in 
paragraph (a), (e), or (h) of this AD, as applicable, at the time 
indicated in that paragraph.
    (i) If no crack is found during any inspection required by 
either paragraph (h)(1) or (h)(2) of this AD, repeat the dye 
penetrant and magnetic particle inspections required by either 
paragraph (h)(1) or (h)(2) of this AD thereafter at intervals not to 
exceed 2,500 landings. Prior to the accumulation of 30,000 or more 
total landings on the MLG piston, do the actions specified in 
paragraph (d)(1) of this AD.
    (j) If any crack is found during any inspection required by 
either paragraph (h)(1) or (h)(2) of this AD, before further flight, 
do the action(s) specified in either paragraph (d)(1) or (d)(2) of 
this AD.

Exception to Actions Referenced in Service Bulletin

    (k) If any discrepancy is found during any inspection while 
accomplishing the preventative modification required by this AD, 
prior to further flight, do applicable corrective action(s) per 
McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated 
December 7, 1999. If the service bulletin specifies to contact the 
manufacturer for appropriate action: Prior to further flight, repair 
in accordance with 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 reference this AD.

Optional Terminating Action

    (l) Replacement of any MLG piston with a MLG piston, P/N 
5935347-517, per McDonnell Douglas Service Bulletin MD80-32-277, 
Revision 04, dated December 7, 1999; constitutes terminating action 
for the requirements of this AD for that MLG piston.

Alternative Methods of Compliance

    (m)(1) 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.


    (2) Alternative methods of compliance, approved previously in 
accordance with AD 96-19-09, amendment 39-9756, are approved as 
alternative methods of compliance with this AD.

Special Flight Permits

    (n) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199

[[Page 59150]]

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 September 28, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-25434 Filed 10-3-00; 8:45 am]
BILLING CODE 4910-13-P