[Federal Register Volume 68, Number 84 (Thursday, May 1, 2003)]
[Rules and Regulations]
[Pages 23183-23186]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-10512]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-170-AD; Amendment 39-13136; AD 2003-09-07]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -
30, -40, and -50 Series Airplanes; and DC-9-81 (MD-81), DC-9-82 (MD-
82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all McDonnell Douglas transport category airplanes listed 
above, that requires a check of the slant pressure panels of the wheel 
wells of the left and right main landing gear (MLG) for water leakage, 
and repair of any leak found. This action is necessary to prevent the 
accumulation of water in the wheel wells of the MLG during flight, 
which could freeze on the lateral control mixer and control cables, 
resulting in restricted lateral control and consequent reduced 
controllability of the airplane. This action is intended to address the 
identified unsafe condition.

DATES: Effective June 5, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 5, 2003.

ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; at the FAA, Los Angeles Aircraft Certification Office, 3960 
Paramount Boulevard, Lakewood, California; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, 
DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all McDonnell Douglas Model DC-9-
10, -20, -30, -40, and -50 series airplanes; and DC-9-81 (MD-81), DC-9-
82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes; was 
published in the Federal Register on November 18, 2002 (67 FR 69494). 
That action proposed to require a check of the slant pressure

[[Page 23184]]

panels of the wheel wells of the left and right main landing gear (MLG) 
for water leakage, and repair of any leak found.

Explanation of New Relevant Service Information

    Since the issuance of the proposed AD, the FAA has reviewed and 
approved Boeing Alert Service Bulletin DC9-53A295, Revision 02, 
including Appendix and Evaluation Form, dated January 6, 2003. (The 
proposed AD refers to Boeing Alert Service Bulletin DC9-53A295, 
Revision 01, dated February 28, 2002, as an acceptable source of 
service information for accomplishment of the proposed actions.) 
Revision 02 of the service bulletin adds no new procedures, though it 
adds two airplanes to the effectivity listing. This change does not 
affect the applicability of this AD because, as proposed, this AD 
applies to all McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 
series airplanes; and DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-
83), DC-9-87 (MD-87), and MD-88 airplanes. Therefore, we have revised 
paragraph (a) of this final rule to refer to Revision 02 of the service 
bulletin as the appropriate source of service information for the 
actions in that paragraph. Also, we have revised paragraph (c) of this 
final rule (which was included as paragraph (b) in the proposed AD) to 
give credit for accomplishing the required actions before the effective 
date of this AD per the original issue or Revision 01 of the service 
bulletin.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Revise Leak Check Procedures

    One commenter requests that the FAA revise certain leak check 
procedures. Specifically, the commenter asks that we allow leak checks 
to be performed at 4 pound-per-square-inch gage (psig) (rather than 1 
and 3 psig), allow operators to apply sealant around the entire seal 
before accomplishing the leak check, and allow operators to trim 
migrated seals within certain limits. The commenter states that the 
leak check at 1 psig is impractical because it is difficult to maintain 
differential pressure of 1 psig, and it is unreasonable to expect an 
operator to do this check consistently and repeatedly. The commenter 
states that the slant pressure panel is a ``plug''-type opening that 
seals with increasing pressure, and most plug-type openings, such as 
doors, leak at 1 psig but are sealed at 3.5 to 4 psig. The commenter 
also states that the seals migrate over time due to flexing of the 
structure, and it has not noted any appreciable effect on the sealing 
capabilities of the slant pressure panel due to such seal migration. 
The commenter suggests that the referenced service bulletin be revised 
to incorporate the requested changes.
    We partially concur with the commenter's request. We do not concur 
to raise the pressure threshold for the leak checks to 4 psig. We 
disagree that the slant pressure panel is a plug-type opening similar 
to a door; the slant pressure panel is intended to be pressure-tight at 
all times. This AD addresses an unsafe condition, the accumulation of 
water in the wheel wells of the MLG, that occurs due to leakage of 
water into the MLG wheel well when the slant pressure panel is not 
pressure-tight. We have determined that a leak check at 1 psig (and 
repairing any leak found during that check) is necessary to ensure 
safety and will ensure that leaks will not occur when the airplane is 
in service. No change to the final rule is needed in this regard.
    We concur with the commenter's request to allow operators the 
option of applying PR-1422 sealant to the fillet seal prior to doing 
the leak check or trimming migrated seals within certain limits. If 
these actions are accomplished, they must be accomplished per a method 
approved by the FAA. We have added a new paragraph (b) to this final 
rule (and reidentified subsequent paragraphs accordingly) to include 
these provisions. We have also added Note 2 to this final rule (and 
reidentified subsequent notes accordingly) to state that application of 
sealant within the limits and per the procedures specified in Boeing 
Service Drawing 5956065 is an approved means of complying with the 
sealant application specified in paragraph (b) of this AD.

Request for Alternative Method of Compliance

    One commenter, an operator, states that, on several of its 
airplanes, it has had cases of water accumulation in the wheel wells of 
the left and right MLG due to pressurization leaks from the slant 
pressure panels. Repairs of such leaks were successful on a limited and 
temporary basis only. Based on its experience with such leaks, the 
commenter developed a program to refurbish slant pressure panels that 
involves replacing the left and right slant pressure panels, gaskets, 
and covers, and resealing the area. The commenter states that it will 
pursue an alternative method of compliance (AMOC) with the proposed AD.
    The commenter makes no specific request for a change to the 
proposed AD. We infer that the commenter is requesting approval of an 
AMOC for the requirements of this AD. The commenter provides no 
technical data to support its request. As provided by paragraph (d) of 
this AD, we may approve a request for an AMOC if data are submitted to 
justify that the commenter's refurbishment process would provide an 
acceptable level of safety. No change to the final rule is needed in 
this regard.

Clarification of Compliance Time

    Paragraph (a) of the proposed AD specifies a compliance threshold 
of ``Prior to the accumulation of 40,000 flight hours since date of 
manufacture.'' We find that it is necessary to clarify this compliance 
threshold in this final rule. This decision is based on our 
determination that ``date of manufacture'' may be interpreted 
differently by different operators. Therefore, we have revised the 
compliance threshold for paragraph (a) of this final rule to ``Prior to 
the accumulation of 40,000 flight hours since the date of issuance of 
the original Airworthiness Certificate or the date of issuance of the 
Export Certificate of Airworthiness, whichever occurs first.'' We find 
that this terminology is generally understood within the industry and 
records will always exist that establish these dates with certainty. As 
a result of these changes, we have moved the compliance threshold and 
grace period for the actions required by paragraph (a) to subparagraphs 
(a)(1) and (a)(2) of this final rule.

Explanation of Editorial Change

    We have changed the service bulletin citation throughout this final 
rule to exclude the Evaluation Form attached to the service bulletin. 
The form is intended to be completed by operators and submitted to the 
airplane manufacturer to provide input on the quality of the service 
bulletin; however, this AD does not include such a requirement.
    Also, the service bulletin citation throughout the proposed AD 
states ``including Appendix A.'' First, we note that the citation 
should have referred to ``Appendix,'' not ``Appendix A,'' and we have 
revised all citations in this final rule accordingly. Second, the 
appendix of the service bulletin contains a form for reporting leak 
check results. As we explained in the preamble of the proposed AD, this 
AD does not require

[[Page 23185]]

such reporting. Therefore, we have changed the service bulletin 
citation throughout this final rule to exclude the appendix.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 1,919 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 1,159 airplanes of U.S. 
registry will be affected by this AD, that it will take approximately 4 
work hours per airplane to accomplish the required leak check, and that 
the average labor rate is $60 per work hour. Based on these figures, 
the cost impact of the AD on U.S. operators is estimated to be 
$278,160, or $240 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the 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 adopted herein will 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 final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2003-09-07 McDonnell Douglas: Amendment 39-13136. Docket 2001-NM-
170-AD.
    Applicability: All Model DC-9-14, DC-9-15, DC-9-15F, DC-9-21, 
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, DC-9-34F, DC-9-41, DC-9-51, DC-9-81 (MD-81), DC-
9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes; 
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 (d) 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 the accumulation of water in the wheel wells of the 
left and right main landing gear (MLG) during flight, which could 
freeze on the lateral control mixer and control cables, resulting in 
restricted lateral control and consequent reduced controllability of 
the airplane, accomplish the following:

Leak Check/Repair

    (a) At the later of the compliance times specified in paragraphs 
(a)(1) and (a)(2) of this AD, do a check of the slant pressure 
panels of the wheel wells of the left and right MLG for water 
leakage (including pressurizing the airplane and checking the panels 
for leaks, depressurizing the airplane to repair leaks, and 
pressurizing the airplane again to verify that all leaks are 
repaired), per the Accomplishment Instructions of Boeing Alert 
Service Bulletin DC9-53A295, Revision 02, excluding Appendix and 
Evaluation Form, dated January 6, 2003. If any leak is found, before 
further flight, repair per the service bulletin. If no leak is 
found, no further action is required by this AD.
    (1) Prior to the accumulation of 40,000 flight hours since the 
date of issuance of the original Airworthiness Certificate or the 
date of issuance of the Export Certificate of Airworthiness, 
whichever occurs first.
    (2) Within 18 months after the effective date of this AD.

Optional Application of Sealant or Trimming of Migrated Seals

    (b) Prior to performing the check for water leakage specified in 
paragraph (a) of this AD, operators, at their option, may apply PR-
1422 sealant to the fillet seal or trim migrated seals, within 
limits specified by and per a method approved by the Manager, Los 
Angeles Aircraft Certification Office (ACO), FAA.

    Note 2: Application of PR-1422 sealant per the procedures 
specified in Boeing Service Drawing 5956065 is an approved means of 
complying with the sealant application provision specified in 
paragraph (b) of this AD.

Credit for Actions Done per Previous Issue of Service Bulletin

    (c) Accomplishment of the check for water leakage and repair of 
leaks found, before the effective date of this AD, per Boeing Alert 
Service Bulletin DC9-53A295, excluding Appendix and Evaluation Form, 
dated May 8, 2001; or Revision 01, dated February 28, 2002; is 
acceptable for compliance with paragraph (a) of this AD.

    Note 3: Although Boeing Alert Service Bulletins DC9-53A295, 
dated May 8, 2001; Revision 01, dated February 28, 2002; and 
Revision 02, dated January 6, 2003; recommend that operators report 
findings to the manufacturer after doing the initial leak check, 
this AD does not contain such a reporting requirement.

Alternative Methods of Compliance

    (d) 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 4: 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

    (e) Special flight permits may be issued in accordance with 
Sec. Sec.  21.197 and 21.199 of the

[[Page 23186]]

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.

Incorporation by Reference

    (f) Unless otherwise provided by this AD, the actions shall be 
done in accordance with Boeing Alert Service Bulletin DC9-53A295, 
Revision 02, excluding Appendix and Evaluation Form, dated January 
6, 2003. This incorporation by reference was approved by the 
Director of the Federal Register in accordance with 5 U.S.C. 552(a) 
and 1 CFR part 51. Copies 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). Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; at the FAA, Los Angeles Aircraft Certification Office, 
3960 Paramount Boulevard, Lakewood, California; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

Effective Date

    (g) This amendment becomes effective on June 5, 2003.

    Issued in Renton, Washington, on April 23, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-10512 Filed 4-30-03; 8:45 am]
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