[Federal Register Volume 67, Number 126 (Monday, July 1, 2002)]
[Proposed Rules]
[Pages 44119-44124]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-16407]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-90-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain McDonnell Douglas Model DC-9 
airplanes and Model MD-88 airplanes, that would have required 
replacement of certain power relays, and subsequent repetitive 
overhauls of the replaced power relays. That proposal was prompted by 
reports indicating that the alternating current (AC) cross-tie relay 
shorted out internally, which caused severe smoke and burn damage to 
the relay, aircraft wiring, and adjacent panels. This new action 
revises the proposed rule by revising the requirements and referencing 
new service information. The actions specified by this new proposed AD 
are intended to prevent internal arcing of the left and right generator 
power relays, auxiliary power relays, and external power relays, and 
consequent smoke and/or fire in the cockpit and cabin.

DATES: Comments must be received by July 26, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-90-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. 99-NM-90-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: 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: Elvin Wheeler, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California 
90712-4137; telephone (562) 627-5344; 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

[[Page 44120]]

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:
     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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-90-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-90-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain McDonnell Douglas Model DC-9 airplanes and Model MD-88 
airplanes, was published as a supplemental notice of proposed 
rulemaking (NPRM) in the Federal Register on June 14, 2001 (66 FR 
32276). That original supplemental NPRM (hereafter referred to as ``the 
first supplemental NPRM'') would have required replacement of certain 
power relays, and subsequent repetitive overhauls of the replaced power 
relays. The first supplemental NPRM was prompted by reports indicating 
that the alternating current (AC) cross-tie relay shorted out 
internally, which caused severe smoke and burn damage to the relay, 
aircraft wiring, and adjacent panels. That condition, if not corrected, 
may result in in-flight electrical fires.

Actions Since Issuance of Previous Proposal

1. Issuance of AD 2001-20-15

    Since the issuance of the first supplemental NPRM, the FAA has 
issued AD 2001-20-15, amendment 39-12463 (66 FR 51857, October 11, 
2001), which is applicable to certain McDonnell Douglas Model DC-9 
airplanes and MD-88 airplanes. That AD requires an inspection to 
determine if a certain AC cross-tie relay is installed; replacement of 
a certain AC cross-tie relay with a new AC cross-tie relay; and 
repetitive cleaning, inspection, repair, and testing of a certain AC 
cross-tie relay. As discussed in the preamble of that AD, we determined 
that AC cross-tie relays having part number (P/N) 914F567-3 or -4 pose 
a more serious safety condition than previously determined in the first 
supplemental NPRM. As a result, actions required for the AC cross-tie 
relays, P/Ns 914F567-3 and -4, that were specified in the first 
supplemental NPRM have been specified in AD 2001-20-15. Therefore, we 
have revised this second supplemental NPRM by removing the actions that 
would have been required for the AC cross-tie relays, P/Ns 914F567-3 
and -4.

2. Issuance of AD 2002-08-09

    The FAA also has issued AD 2002-08-09, amendment 39-12717 (67 FR 
19637, April 23, 2002), which is applicable to one McDonnell Douglas 
Model DC-9-31 airplane, fuselage number 0705. The requirements of that 
AD for the DC-9-31 airplane are identical to those described above for 
the airplanes affected by AD 2001-20-15.

3. Explanation of New Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
DC9-24A191, Revision 01, dated January 9, 2002. The service bulletin 
describes procedures for a one-time inspection of the generator power 
relays, auxiliary power relays, and external power relays to determine 
if a certain Sundstrand (Westinghouse) P/N is installed; and corrective 
actions, if necessary. The corrective actions include modifying and 
reidentifying the power relay assemblies; installing certain power 
relay assemblies within service interval limits; replacing the existing 
power relay assemblies with power relay assemblies that are within 
service interval limits; and cleaning, inspecting, repairing, and 
testing of relay assemblies; as applicable. Accomplishment of the 
actions specified in the service bulletin is intended to adequately 
address the identified unsafe condition.

4. Differences Between the Second Supplemental NPRM and the Referenced 
Service Bulletin

    Operators should note that, although the procedures described in 
Boeing Alert Service Bulletin DC9-24A191, Revision 01, dated January 8, 
2002, specify maintenance (i.e., clean, inspect, repair, and test) of 
power relays, Sundstrand (Westinghouse) P/N 9008D09 series, when they 
are beyond service interval limits, the second supplemental NPRM does 
not require those procedures. For further explanation, see heading 
``Request to Delete Certain Requirements'' in the preamble of the 
second supplemental NPRM.
    Operators should also note that the second supplemental NPRM would 
not require installation of certain power relays or replacement of the 
existing power relays with power relays that are ``within service 
interval limits'' (i.e., 7,000 flight hours) as described in the 
service bulletin. The FAA has determined that any generator power 
relay, auxiliary power relay, or external power relay having Sundstrand 
(Westinghouse) P/N 914F567-4 that is removed from the airplane must go 
through maintenance and be made serviceable before the power relay can 
be reinstalled on an airplane. Therefore, the second supplemental NPRM 
would require cleaning, inspecting, repairing, and testing of power 
relays having Sundstrand (Westinghouse) P/N 914F567-4, or replacing 
those power relays with serviceable power relays having Sundstrand 
(Westinghouse) P/N 9008D09 series or 914F567-4. The second supplemental 
NPRM also would require subsequent repetitive cleaning, inspecting, 
repairing, and testing of power relays having Sundstrand (Westinghouse) 
P/N 914F567-4.

Comments Received to First Supplemental NPRM

    Due consideration has been given to the comments received in 
response to the first supplemental NPRM.

Request To Delete Certain Requirements

    Several commenters request that the repetitive overhauls for power 
relay, Sundstrand (Westinghouse) P/N 9008D09 series, specified in 
paragraph (c) of the first supplemental NPRM, be deleted. The 
commenters state that there

[[Page 44121]]

are no failure modes for that relay that result in the identified 
unsafe condition specified in the first supplemental NPRM. One 
commenter states that the design of the main contact arc box for this 
relay is entirely different than that of power relays, Sundstrand 
(Westinghouse) P/Ns 914F567-3 and -4, and is not susceptible to the 
same type of failure in the AC cross-tie position.
    The FAA agrees that power relays having Sundstrand (Westinghouse) 
P/N 9008D09 series are not subject to the identified unsafe condition 
of the second supplemental NPRM. Therefore, we have deleted the 
repetitive overhaul requirements for P/N 9008D09 from the second 
supplemental NPRM.

Requests for Clarification of Applicability

    Several commenters request clarification of the applicability to 
ensure that operators are cognizant of the repetitive overhaul 
requirements in paragraphs (b), (c), and (d) of the first supplemental 
NPRM. The commenters note that the applicability of the first 
supplemental NPRM affects ``Model DC-9 series airplanes and Model MD-88 
airplanes, equipped with Westinghouse alternating current (AC) power 
relays, part number (P/N) 914F567-3.'' However, the proposed repetitive 
overhauls specified in paragraphs (b), (c), and (d) of the first 
supplemental NPRM are for airplanes equipped with power relays, 
Sundstrand (Westinghouse) P/Ns 914F567-4 and 9008D09 series, and for 
airplanes on which the flight hours since modification or installation 
of the AC power relay cannot be determined.
    The FAA agrees that the applicability needs to be clarified. 
Because the proposed actions for AC cross-tie relays having Sundstrand 
(Westinghouse) P/N 914F567-3, and power relays having Sundstrand 
(Westinghouse) P/N 9008D09 series, have been deleted from the second 
supplemental NPRM, only the left and right generator power relays, 
auxiliary power relays, and external power relays, Sundstrand 
(Westinghouse) P/Ns 914F567-3 and -4, are subject to the requirements 
of the second supplemental NPRM. We have determined that a one-time 
inspection of the left and right generator power relays, auxiliary 
power relays, and external power relays to determine if Sundstrand 
(Westinghouse) P/N 914F567-3 or -4 is installed, is necessary (see 
heading ``3. Explanation of New Service Information''). Therefore, we 
have deleted the phrase ``equipped with Westinghouse alternating 
current (AC) power relays, part number (P/N) 914F567-3'' from the 
applicability of the second supplemental NPRM.
    Further, we have revised model designations in the applicability of 
the second supplemental NPRM to reflect the model designations as 
published in the most recent type certificate data sheet for the 
affected airplanes. These model designations are also identified in the 
effectivity of the referenced service bulletin. Because of these 
changes, we have also updated the number of affected airplanes in the 
Cost Impact Section of the second supplemental NPRM.

Requests To Revise Certain Compliance Times

    Several commenters request that the 30-day compliance time for 
overhauling the power relays on the airplanes on which the flight hours 
since modification or installation of the AC power relay cannot be 
determined, as specified in paragraph (d) of the first supplemental 
NPRM, be extended.
    Several commenters suggest a compliance time of 12 months. Two of 
these commenters request the extension for AC power relays, Sundstrand 
(Westinghouse) P/Ns 914F567-3 and -4, and power relays, Sundstrand 
(Westinghouse) P/N 9008D09 series, of an undetermined service life for 
all positions. One of the commenters requests the extension for AC 
power relays, Sundstrand (Westinghouse) P/Ns 914F567-3 and -4, of an 
undetermined service life in the cross-tie position only. The 
commenters note that paragraph (a) of the first supplemental NPRM 
allows AC power relays, Sundstrand (Westinghouse) P/N 914F567-3, for 
all positions, to remain in service for 12 months before replacement. 
Since the primary safety concern of the first supplemental NPRM is 
related to power relays, Sundstrand (Westinghouse) P/N 914F567-3, the 
commenters state that the compliance time for the power relays, 
Sundstrand (Westinghouse) P/N 914F567-4, of an undetermined service 
life should be the same as that of power relays, Sundstrand 
(Westinghouse) P/N 914F567-3 (i.e., 12 months). One of these commenters 
and another commenter state that 30 days is not enough time to obtain 
parts. One commenter also states that the lead-time for obtaining parts 
is 245 days.
    One commenter suggests a compliance time of two years or at the 
next heavy maintenance check, whichever occurs first, and another 
commenter suggests 90 or 120 days. The two commenters support the 30-
day compliance time for power relays at the cross-tie position only, 
but request the extensions for all relays at the generator power, 
auxiliary power, and external power positions. A third commenter also 
supports the 30-day compliance time for power relays at the cross-tie 
position only, but does not request an extension for the power relays 
in the other positions. One commenter states that relays at the 
generator power, auxiliary power, and external power positions are not 
as susceptible to the identified unsafe condition and should be allowed 
to remain on the airplane until the next heavy maintenance check. The 
commenters also state that such an extension for those power relays 
will not compromise safety and will allow the proposed overhaul to be 
accomplished during normal maintenance schedules.
    One commenter requests that the 30-day grace period specified in 
paragraphs (b)(2) and (c)(2) of the first supplemental NPRM be extended 
for relays at the generator power, auxiliary power, and external power 
positions only. The commenter provides similar justification as 
identified above for extending the compliance time of paragraph (d) of 
the first supplemental NPRM.
    The FAA partially agrees. As discussed previously, certain actions 
required for the AC cross-tie relay having Sundstrand (Westinghouse) P/
Ns 914F567-3 and -4, and Sundstrand (Westinghouse) power relays having 
P/N 9008D09 series, that were specified in the first supplemental NPRM 
have been deleted from the second supplemental NPRM. Therefore, the 
commenters' requested changes for those power relays in the second 
supplemental NPRM are unnecessary.
    However, we agree that, for airplanes on which the flight hours 
since installation of any generator power relay, auxiliary power relay, 
or external power relay, Sundstrand (Westinghouse) P/N 914F567-4, 
cannot be determined, the compliance time specified in paragraph (d) of 
the first supplemental NPRM (redesignated as paragraph (c)(2) in the 
second supplemental NPRM) should be extended from 30 days to 24 months. 
We also agree that the 30-day grace period specified in paragraph 
(b)(2) of the first supplemental NPRM (redesignated as paragraph (c)(1) 
in the second supplemental NPRM) for relays at the generator power, 
auxiliary power, and external power positions should be extended to 24 
months.
    We have reviewed the service bulletin (discussed previously) 
submitted by the manufacturer as to recommended maintenance (i.e., 
cleaning, inspecting, repairing, and testing) period (i.e., 24

[[Page 44122]]

months). We have determined that extending the proposed compliance time 
of 30 days specified in paragraph (d) of the first supplemental NPRM 
(redesignated as paragraph (c)(2) in the second supplemental NPRM) and 
the proposed grace period of 30 days specified in paragraph (b)(2) of 
the first supplemental NPRM (now specified in paragraph (c)(1) in the 
second supplemental NPRM) to 24 months will provide an acceptable level 
of safety. Therefore, we have revised the compliance time for 
maintenance of generator power relays, auxiliary power relays, and 
external power relays, Sundstrand (Westinghouse) P/N 914F567-4, 
specified in the second supplemental NPRM accordingly.

Request To Reconsider Use of Term ``Overhaul''

    Several commenters request that the FAA reconsider the use of the 
term ``overhaul'' in the first supplemental NPRM. One commenter 
suggests using the phrase ``between removals'' instead to avoid 
misinterpretation. Another commenter suggests the use of the term 
``maintenance.'' One commenter notes that power relays, Sundstrand 
(Westinghouse) P/Ns 914F567-3 and -4, are maintained with an overhaul 
manual, while power relays, Sundstrand (Westinghouse) P/N 9008D09 
series, are maintained with a component maintenance manual (CMM). This 
commenter states that the Common Support Data Dictionary (CSDD) defines 
overhaul as ``The work necessary to return an item to the highest 
standard specified in the relevant manual.'' Therefore, the commenter 
concludes that an ``overhaul'' should not be mandated for power relay, 
Sundstrand (Westinghouse) P/N 9008D09 series, because it is beyond the 
level of maintenance required to address the accumulation of 
contamination. Based on industry history, the commenter also states 
that maintenance (i.e., cleaning of the contacts and a check and 
repair) for power relay, Sundstrand (Westinghouse) P/N 9008D09 series, 
per the CMM, is sufficient.
    The FAA agrees with the commenters that the use of the term 
``overhaul'' in the first supplemental NPRM is not correct. Our intent 
was that the repetitive overhauls remove the metallic dust from 
electrical contact wear that accumulates in the power relays. We find 
that such removal can be accomplished by cleaning, inspecting, 
repairing, and testing of the generator power relays, auxiliary power 
relays, and external power relays (i.e., maintenance), per Boeing Alert 
Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002 
(described previously). Boeing Alert Service Bulletin DC9-24A191 
references Westinghouse Overhaul Manual 24-20-46 (for relays, P/N 
914F567-4) and Hamilton Sundstrand CMM 24-20-87 (for relays, P/N 
9008D08 series) as additional sources of service information for 
accomplishing the proposed repetitive maintenance actions. However, as 
discussed previously, we have deleted the repetitive overhaul 
requirements for power relays, Sundstrand (Westinghouse) P/N 9008D09 
series, from the second supplemental NPRM. Therefore, we have revised 
the second supplemental NPRM to require repetitive cleaning, 
inspecting, repairing, and testing of generator power relays, auxiliary 
power relays, and external power relays, Sundstrand (Westinghouse) P/N 
914F567-4, only.

Request To Limit Actions to Cross-Tie Position

    Two commenters request that the actions required by the first 
supplemental NPRM be limited to power relays in the cross-tie position 
only, which is identified as the unsafe condition in the first 
supplemental NPRM. One commenter states that there are no data to 
support the proposed actions for AC power relays at the generator 
power, auxiliary power, or external power positions. The commenters 
understand the FAA's concern that if all relays are the same P/N, there 
may be a risk of putting the wrong part in the cross-tie position. 
However, the commenters contend that operators have demonstrated their 
capability to deal with position-related restrictions for parts on 
airplanes, and that they can ensure that no relay, Sundstrand 
(Westinghouse) P/N 914F567-3, is installed in the cross-tie position.
    One commenter states that it does not support the need for 
replacement of Westinghouse AC power relays, P/N 914F567-3, or the 
establishment of time between overhaul (TBO) limits for any of the AC 
power relays. The commenter uses relays, P/Ns 914F567-3, 914F567-4, 
9008D09-1, and 9008D09-2, interchangeably in all seven positions, 
including the cross-tie position. The commenter states that its service 
experience indicates that each of these relays operate reliably well 
beyond the proposed TBO limits.
    The FAA does not agree. Although there have been no reported cases 
of the power relays at the generator power, auxiliary power, or 
external power positions shorting out internally, the potential for an 
electrical short still exists when a power relay, Sundstrand 
(Westinghouse) P/N 914F567-3, is installed in those positions. The 
accumulation of conductive particle material on any power relays, 
Sundstrand (Westinghouse) P/N 914F567-3, can build an electrical path 
to its adjacent terminal and cause a phase-to-phase short circuit. Such 
a short circuit will result in internal arcing of the power relays and 
consequent smoke and/or fire in the cockpit and cabin. The second 
supplemental NPRM addresses that potential unsafe condition by removing 
generator power relays, auxiliary power relays, and external power 
relays, Sundstrand (Westinghouse) P/N 914F567-3, and periodically 
removing the build-up of conductive particle material from the 
generator power relays, auxiliary power relays, and external power 
relays, Sundstrand (Westinghouse) P/N 914F567-4.
    However, we find that clarification of the wording of the unsafe 
condition of the second supplemental NPRM is necessary, because the 
identified unsafe condition for AC cross-tie relays, Sundstrand 
(Westinghouse) P/N 914F567-3 and -4, is now being addressed in AD 2001-
20-15. Therefore, we have revised the unsafe condition specified 
throughout the second supplemental NPRM to read ``to prevent internal 
arcing of the left and right generator power relays, auxiliary power 
relays, and external power relays, and consequent smoke and/or fire in 
the cockpit and cabin.''

Request To Include a New Paragraph for Spares

    One commenter requests that a new paragraph be added to the first 
supplemental NPRM to state, ``As of the effective date of this AD, no 
person shall install an AC power relay P/N 914F567-3 at the cross-tie 
relay position on any airplane.'' The commenter states that this 
paragraph would prevent operators from putting an unmodified relay in 
the cross-tie position during the time period that unmodified relays 
will be available.
    The FAA does not agree. As discussed previously, we have revised 
the second supplemental NPRM by removing the actions that would have 
been required for the AC cross-tie relays, Sundstrand (Westinghouse) P/
N 914F567-3. Therefore, no change to the second supplemental NPRM is 
necessary in this regard.

Conclusion

    Since these changes expand the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide

[[Page 44123]]

additional opportunity for public comment.

Cost Impact

    There are approximately 1,991 Model DC-9 airplanes and Model MD-88 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 1,219 airplanes of U.S. registry would be affected by 
this proposed AD, that it would take approximately 2 work hours per 
airplane to accomplish the proposed inspection, and that the average 
labor rate is $60 per work hour. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be 
$146,288, or $120 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the 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.

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 adding the following new 
airworthiness directive:

McDonnell Douglas: Docket 99-NM-90-AD.

    Applicability: This AD applies to the following airplanes, 
certificated in any category, as listed in Boeing Alert Service 
Bulletin DC9-24A191, Revision 01, dated January 9, 2002:

McDonnell Douglas Model

DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, and DC-9-15F airplanes
DC-9-21 airplanes
DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A, C-9B), 
DC-9-33F, DC-9-34, and DC-9-34F airplanes
DC-9-41 airplanes
DC-9-51 airplanes
DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-
87) airplanes
MD-88 airplanes

    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 (e) 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 internal arcing of the left and right generator power 
relays, auxiliary power relays, and external power relays, and 
consequent smoke and/or fire in the cockpit and cabin, accomplish 
the following:

Inspection

    (a) Within 24 months after the effective date of this AD, 
perform a one-time inspection of the left and right generator power 
relays, auxiliary power relays, and external power relays, to 
determine if Sundstrand (Westinghouse) part number (P/N) 914F567-3 
or -4, is installed, per Boeing Alert Service Bulletin DC9-24A191, 
Revision 01, dated January 9, 2002.

Replacement or Modification/Reidentification of Any Generator Power 
Relay, Auxiliary Power Relay, or External Power Relay, P/N 914F567-3

    (b) If any generator power relay, auxiliary power relay, or 
external power relay, Sundstrand (Westinghouse) P/N 914F567-3, is 
found installed during the inspection required by paragraph (a) of 
this AD, within 24 months after the effective date of this AD, do 
either action(s) specified in paragraph (b)(1) or (b)(2) of this AD 
per the Accomplishment Instructions of Boeing Alert Service Bulletin 
DC9-24A191, Revision 01, dated January 9, 2002.
    (1) Replace power relay having Sundstrand (Westinghouse) P/N 
914F567-3 with either a serviceable power relay having Sundstrand 
(Westinghouse) P/N 9008D09 series or 914F567-4.
    (2) Modify the power relay, Sundstrand (Westinghouse) P/N 
914F567-3, to a -4 configuration.

Maintenance or Replacement of Any Generator Power Relay, Auxiliary 
Power Relay, or External Power Relay, P/N 914F567-4

    (c) If any generator power relay, auxiliary power relay, or 
external power relay, Sundstrand (Westinghouse) P/N 914F567-4, is 
found installed during the inspection required by paragraph (a) of 
this AD, clean, inspect, repair, and test the relay, or replace the 
power relay with a serviceable power relay having Sundstrand 
(Westinghouse) P/N 9008D09 series or 914F567-4; per Boeing Alert 
Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002; at 
the time specified in paragraph (c)(1) of this AD, except as 
provided by paragraph (c)(2) of this AD.
    (1) Within 7,000 flight hours after installation of the 
generator power relay, auxiliary power relay, or external power 
relay, Sundstrand (Westinghouse) P/N 914F567-4, or within 24 months 
after the effective date of this AD, whichever occurs later.
    (2) For airplanes on which the flight hours since installation 
of any generator power relay, auxiliary power relay, or external 
power relay, Sundstrand (Westinghouse) P/N 914F567-4, cannot be 
determined: Within 24 months after the effective date of this AD.

Repetitive Maintenance of Generator Power Relay, Auxiliary Power Relay, 
or External Power Relay, Sundstrand (Westinghouse) P/N 914F567-4

    (d) Before or upon the accumulation of 7,000 flight hours on any 
generator power relay, auxiliary power relay, or external power 
relay, Sundstrand (Westinghouse) P/N 914F567-4 since accomplishing 
the action(s) required by either paragraph (b) or (c) of this AD, as 
applicable, clean, inspect, repair, and test; per Boeing Alert 
Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002. 
Thereafter, repeat these actions at intervals not to exceed the 
accumulation of 7,000 flight hours on the power relay.

Alternative Methods of Compliance

    (e) An alternative method of compliance or adjustment of the 
compliance time that

[[Page 44124]]

provides an acceptable level of safety may be used if approved by 
the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. 
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.

Special Flight Permits

    (f) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 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 June 24, 2002.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-16407 Filed 6-28-02; 8:45 am]
BILLING CODE 4910-13-P