[Federal Register Volume 68, Number 103 (Thursday, May 29, 2003)]
[Rules and Regulations]
[Pages 31962-31965]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-13118]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-28-AD; Amendment 39-13160; AD 2003-11-01]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to all Boeing Model 747 series airplanes, that 
currently requires periodic inspections and cleaning of the drainage 
system cavity of the canted pressure deck, aft of the wing center 
section. This amendment adds new repetitive tests and inspections for 
discrepancies of the drainage system of the canted pressure deck; and 
corrective actions, if necessary. This amendment also terminates the 
requirements of the existing AD. The actions specified by this AD are 
intended to prevent ice accumulation on the lateral flight control 
cables and/or components due to water entering the wheel well of the 
landing gear and freezing, which could restrict or jam control cable 
movement, resulting in loss of controllability of the airplane. This 
action is intended to address the identified unsafe condition.

DATES: Effective July 3, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 3, 2003.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Rick Kawaguchi, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6434; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 89-12-07, 
amendment 39-6232 (54 FR 24161, June 6, 1989), which is applicable to 
all Boeing Model 747 series airplanes, was published in the Federal 
Register on October 16, 2002 (67 FR 63856). The action proposed to 
continue to require periodic inspections and cleaning of the drainage 
system cavity of the canted pressure deck, aft of the wing center 
section. The new action proposed to add new repetitive tests and 
inspections for discrepancies of the drainage system of the canted 
pressure deck located in the wheel wells of the main landing gear of 
the left and right wings; and corrective actions, if necessary. The new 
action also proposed to terminate the requirements of the existing AD.

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 Change Compliance Times

    One commenter (the manufacturer) asks that the compliance times 
specified in paragraphs (b), (c), and (d) of the proposed AD be changed 
to allow a grace period for operators of new airplanes. The commenter 
states that the drain system is already open and clean when the 
airplane is delivered.
    The FAA agrees with the commenter that the drain system should 
already be open and clean when the airplane is delivered. Therefore, 
paragraphs (b), (d), and (e) of this final rule (paragraphs (b), (c), 
and (d) of the proposed AD) have been changed to allow a grace period 
relative to the date of issuance of the original airworthiness 
certificate, or the date of issuance of the export certificate of 
airworthiness, whichever is first.

Request To Clarify Summary Section

    The same commenter asks that the Summary section in the proposed AD 
be changed, for clarification, to limit the location specified to ``the 
drainage system of the canted pressure deck'' to allow operators some 
leeway when doing the maintenance tasks. The commenter states that the 
intent of the proposed AD is to keep the drain system open and clean, 
and the phrase ``drainage system of the canted pressure deck'' refers 
to a series of drains normally mounted to the canted

[[Page 31963]]

pressure deck. The commenter adds that the drain system includes 
different drains and drain lines, and the drain lines are mounted in 
the wheel well area and the area above the fairings below the wing. The 
commenter notes that the phrase ``wing landing gear wheel well'' is 
used interchangeably with the phrase ``wheel well of the main landing 
gear'' throughout the proposed AD.
    We agree with the commenter, and we have changed the applicable 
sections in this final rule for clarification to the phrase ``wheel 
well of the landing gear.''
    The same commenter asks that the unsafe condition in the Summary 
section be changed to ``The actions specified by this AD are intended 
to prevent ice accumulation on the lateral flight control cables and/or 
components due to water entering the wheel well of the MLG and 
freezing, which could restrict or jam control cable movement, resulting 
in degraded or loss of controllability of the airplane.'' The commenter 
states that this would provide a better explanation of the unsafe 
condition.
    We agree to add ``and/or components,'' but we do not agree to add 
the word ``degraded.'' The phrase ``loss of controllability of the 
airplane'' adequately describes the end-level effect on the airplane. 
``Degraded controllability'' would not necessarily result in loss of 
control of the airplane, unless there were other contributing factors. 
We do not list all possible conditions that could result from ice 
accumulation--only the end-level effect.

Request To Clarify Certain Sections in the Preamble

    The same commenter asks that the first and third paragraphs of the 
Explanation of Relevant Service Information section in the preamble of 
the proposed AD be changed to remove the phrase ``located in the wheel 
wells of the main landing gear of the left and right wings'' for 
clarification. The commenter also asks that the same phrase in the 
first paragraph of the Explanation of Requirements of Proposed Rule 
section be removed for clarification. The commenter also asks for minor 
editorial changes.
    We acknowledge and agree with the commenter's remarks on the 
preamble of the proposed AD; however, the sections referred to are not 
restated in this final rule. Therefore, no change to the final rule is 
necessary in this regard.

Request To Change Paragraph (b)(1)

    Two commenters ask for changes to paragraph (b)(1) of the proposed 
AD. One commenter states that the tests specified in paragraph (b)(1) 
do not allow any leeway to the airline. The commenter adds that 
operators may find it easier to use a vacuum or ``snake'' to do the 
test and notes that this paragraph should be changed to allow other 
methods to verify the drains are open and clean. The other commenter 
suggests that the drains at left buttock line (LBL) 45.75 and LBL 65.00 
be used as an alternative means for determining the condition of the 
drainage of the canted pressure deck.
    We do not agree to change paragraph (c)(1) of the final rule 
(paragraph (b)(1) of the proposed AD). We acknowledge that alternate 
inspection methods can be used to ensure that the drains are open and 
clean if such methods are submitted to the FAA for approval as an 
alternative method of compliance (AMOC), as provided in paragraph 
(g)(1) of this final rule. No change to the final rule is necessary in 
this regard.

Request To Change Paragraph (b)(2)

    One commenter asks that the last sentence in paragraph (b)(2) of 
the proposed AD be changed to state, ``Accomplishment of paragraphs 
(b)(1) and (b)(2) of this AD replaces the requirements in paragraph (a) 
of this AD.'' The commenter states that the sentence is not accurate as 
written because doing the procedures specified in Work Package 2 does 
not verify that the drains are open and clean. The commenter adds that 
paragraph (b)(2) does not terminate the requirements in paragraph (a) 
of the proposed AD; it merely replaces them with new requirements.
    We do not agree with the commenter. The inspection procedures 
required by paragraph (c)(2) of the final rule (paragraph (b)(2) of the 
proposed AD) meet the requirements specified in paragraph (a) of the 
final rule, which is to verify that all drains are open and clean. We 
acknowledge that the inspections required by paragraph (c)(1) of the 
final rule also address inspections of the drains, but the test in that 
paragraph goes beyond the inspection requirements in paragraph (a) of 
this final rule. No change to the final rule is necessary in this 
regard.

Request To Withdraw Proposed AD

    Three commenters state that, since the issuance of AD 89-12-07, 
they have had no findings of drainage problems in the canted pressure 
deck area on the subject airplanes. The comments are as follows:
    [sbull] One commenter states that it has incorporated numerous 
service bulletin modifications to improve the drainage of the subject 
area. The commenter adds that it would be interesting to determine if 
such modifications have been incorporated on the airplanes specified in 
the proposed AD and if the inspections and cleaning required by AD 89-
12-07 have been done, as the commenter has done. The commenter also 
notes that the proposed AD is not necessary for Model 747-400 series 
airplanes because all the improvement modifications were incorporated 
per the service bulletins.
    [sbull] One commenter states that the actions required by the 
proposed AD are done per AD 89-12-07, and per the current maintenance 
review board (MRB) inspections.
    [sbull] One commenter provides data showing its inspection results 
and states that, as the data indicate, it has found virtually no 
trapped water in the canted pressure deck, and based on this, the 
actions required by the proposed AD are not necessary.
    We infer that the commenters are asking that the proposed AD be 
withdrawn, and we do not agree. We have received several reports on 
Model 747-400 series airplanes, and other airplanes on which the 
service bulletin modifications have been incorporated to improve the 
drainage of the subject area, and water is still entering the landing 
gear wheel well and freezing. Operators of these airplanes have been 
inspecting the subject area per the requirements in AD 89-12-07. In 
addition, because the procedures specified in MRBs vary from operator 
to operator, there are no assurances that each operator's MRB contains 
the equivalent actions required by this AD. We have determined that the 
inspections specified in the existing MRB and AD 89-12-07 do not 
provide an adequate level of safety; therefore, we have determined that 
this final rule is appropriate and warranted. No change is made to the 
final rule in this regard.

Request To Extend Repetitive Test Intervals

    One commenter asks that the repetitive interval for the cabin 
pressurization tests required by paragraph (d) of the proposed AD be 
extended to every 8 years so the tests can be at the ``D'' check 
interval because some operators have been using this interval for 
several years. The commenter states that the intervals specified in the 
proposed AD are taken from the referenced service information, and seem 
to be based on the MRB intervals and the present average intervals used 
by 747 operators. The commenter adds that the proposed AD should 
provide technically possible maximum intervals with substantiation. The 
commenter notes that the referenced service information and the

[[Page 31964]]

proposed AD do not make any distinction between the oldest, least 
modified Model 747-100 airplane, and the latest Model 747-400 airplane. 
The commenter states that it would be reasonable to take the airplane 
type and modification status into account when determining the test 
intervals.
    We do not agree with the commenter that operators are entitled to 
inspection intervals based on the maximum intervals between maintenance 
checks, nor do we agree that the intervals should be adjusted based on 
the level of modification. As stated under ``Request To Withdraw 
Proposed AD,'' we have received reports of freezing problems found on 
Model 747-400 series airplanes and modified airplanes, as well as 
airplanes not yet modified. If operators can provide substantiating 
data for adjustment of the repetitive test intervals required by 
paragraph (e) of the final rule (paragraph (d) of the proposed AD), we 
will consider approving the commenter's request as an AMOC, as provided 
in paragraph (g)(1) of this final rule.

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 1,127 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 255 airplanes of U.S. 
registry will be affected by this AD.
    It takes approximately 1 work hour per airplane to accomplish the 
actions that are required by AD 89-12-07, at an average labor rate of 
$60 per work hour. Based on these figures, the cost impact of the 
currently required actions is estimated to be $60 per airplane, per 
inspection cycle.
    It will take approximately 12 work hours per airplane to accomplish 
the test/inspection/cleaning of the drainage system specified in Work 
Packages 1 and 2 of Boeing Alert Service Bulletin 747-51A2057, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the test/inspection/cleaning required by this AD on U.S. 
operators is estimated to be $183,600, or $720 per airplane, per cycle.
    It will take approximately 4 work hours per airplane to accomplish 
the inspection specified in Work Package 3 of the service bulletin, at 
an average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the inspection required by this AD on U.S. operators is 
estimated to be $61,200, or $240 per airplane, per inspection cycle.
    It will take approximately 4 work hours per airplane to accomplish 
the cabin pressurization test specified in Work Package 4 of the 
service bulletin, at an average labor rate of $60 per work hour. Based 
on these figures, the cost impact of the test required by this AD on 
U.S. operators is estimated to be $61,200, or $240 per airplane, per 
test cycle.
    The cost impact figures discussed above are 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 removing amendment 39-6232 (54 FR 24161, 
June 6, 1989), and by adding a new airworthiness directive (AD), 
amendment 39-13160, to read as follows:

2003-11-01 Boeing: Amendment 39-13160. Docket 2002-NM-28-AD. 
Supersedes AD 89-12-07, Amendment 39-6232.

    Applicability: All Model 747 series 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 (g)(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 ice accumulation on the lateral flight control cables 
and/or components due to water entering the wheel well of the 
landing gear and freezing, which could restrict or jam control cable 
movement, resulting in loss of controllability of the airplane, 
accomplish the following:

Restatement of Requirements of AD 89-12-07

Repetitive Inspections/Cleaning

    (a) Within 15 months after July 10, 1989 (the effective date of 
AD 89-12-07, amendment 39-6232), unless accomplished 3 months before 
July 10, 1989, and thereafter at intervals not to exceed 18 months: 
Gain access to the cavity aft of the wing center section and remove 
all debris and foreign material, clean the cavity, and verify all 
drains are open and clean.

New Requirements of This AD

Repetitive Tests/Inspections of the Drainage System/Corrective 
Action

    (b) At the later of the times specified in paragraphs (b)(1) and 
(b)(2) of this AD, do the actions required by paragraph (c) of this 
AD.

[[Page 31965]]

    (1) Within 18 months after the effective date of this AD.
    (2) Within 18 months since date of issuance of the original 
airworthiness certificate, or since date of issuance of the export 
certificate of airworthiness, whichever is first.
    (c) Do the actions specified in paragraphs (c)(1), (c)(2), and 
(c)(3) of this AD per the Work Instructions of Boeing Alert Service 
Bulletin 747-51A2057, dated February 21, 2002.
    (1) Do a test (including doing a general visual inspection of 
the external drains, reducer, and drain lines, and sending 3 to 5 
pounds per square inch compressed air through the drain line) of the 
drainage system of the canted pressure deck for discrepancies 
(including damage, holes, signs of frozen water, and signs of 
blockage), per Work Package 1 of the Work Instructions of the 
service bulletin. Repeat the test at least every 18 months.
    (2) Clean the drainage system for the canted pressure deck, and 
do a general visual inspection of the system for discrepancies, per 
Work Package 2 of the Work Instructions of the service bulletin. 
Repeat the cleaning and inspection at least every 18 months. 
Accomplishment of this paragraph terminates the requirements in 
paragraph (a) of this AD.
    (3) Except as required by paragraph (f) of this AD: If any 
discrepancy is found during any inspection or test required by 
paragraphs (c)(1) and (c)(2) of this AD, before further flight, 
repair per the Work Instructions of the service bulletin.

Repetitive Inspections of the Canted Pressure Deck/Corrective Action

    (d) At the later of the times specified in paragraphs (d)(1) and 
(d)(2) of this AD: Do a general visual inspection of the canted 
pressure deck for discrepancies (including loose or missing 
fasteners; loose, missing, or cracked sealant; and leak paths), per 
Work Package 3 of the Work Instructions of Boeing Alert Service 
Bulletin 747-51A2057, dated February 21, 2002. If any discrepancy is 
found, before further flight, repair (including replacing any loose 
or missing fastener or loose, missing, or cracked sealant; and 
repairing any leak found) per the service bulletin; except as 
required by paragraph (f) of this AD. Repeat the inspection at least 
every 36 months.

    Note 2: 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.''

    (1) Within 36 months after the effective date of this AD.
    (2) Within 36 months since date of issuance of the original 
airworthiness certificate, or since date of issuance of the export 
certificate of airworthiness, whichever is first.

Repetitive Cabin Pressurization Tests/Corrective Action

    (e) At the later of the times specified in paragraphs (e)(1) and 
(e)(2) of this AD: Do a cabin pressurization test to check for leaks 
in the canted pressure deck, per Work Package 4 of the Work 
Instructions of Boeing Alert Service Bulletin 747-51A2057, dated 
February 21, 2002. If any leak is found, before further flight, 
repair per the service bulletin; except as required by paragraph (f) 
of this AD. Repeat the cabin pressurization test at least every 72 
months.
    (1) Within 72 months after the effective date of this AD.
    (2) Within 72 months since date of issuance of the original 
airworthiness certificate, or since date of issuance of the export 
certificate of airworthiness, whichever is first.

Corrective Action per Seattle Aircraft Certification Office (ACO)

    (f) If any discrepancy is found during any inspection or test 
required by this AD and the service bulletin specifies to contact 
Boeing for appropriate action: Before further flight, repair per a 
method approved by the Manager, Seattle ACO, FAA; or per data 
meeting the type certification basis of the airplane approved by a 
Boeing Company Designated Engineering Representative who has been 
authorized by the Manager, Seattle ACO, to make such findings. For a 
repair method to be approved, the approval must specifically 
reference this AD.

Alternative Methods of Compliance

    (g)(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, Seattle ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Seattle ACO.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 89-12-07, amendment 39-6232, are approved as 
alternative methods of compliance with paragraph (c)(2) of this AD.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (h) 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.

Incorporation by Reference

    (i) Unless otherwise provided in this AD, the actions shall be 
done in accordance with Boeing Alert Service Bulletin 747-51A2057, 
dated February 21, 2002. 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 Airplane Group, P.O. Box 3707, Seattle, Washington 
98124-2207. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

Effective Date

    (j) This amendment becomes effective on July 3, 2003.

    Issued in Renton, Washington, on May 20, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-13118 Filed 5-28-03; 8:45 am]
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