[Federal Register Volume 67, Number 200 (Wednesday, October 16, 2002)]
[Proposed Rules]
[Pages 63856-63858]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-26203]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 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. 67, No. 200 / Wednesday, October 16, 2002 / 
Proposed Rules  

[[Page 63856]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-28-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to 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 action would 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 (MLG) 
of the left and right wings; and corrective actions, if necessary. The 
action would also terminate the requirements of the existing AD. The 
actions specified by the proposed AD are intended to prevent ice 
accumulation on the lateral flight control cables due to water entering 
the wheel well of the MLG and freezing, which could restrict or jam 
control cable movement, resulting in loss of controllability of the 
airplane.

DATES: Comments must be received by December 2, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-28-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. 2002-NM-28-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 Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Technical Information: Rick Kawaguchi, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-1153; fax (425) 227-1181.
    Other Information: Sandi Carli, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 687-4243, fax (425) 687-4248. Questions 
or comments may also be sent via the Internet using the following 
address: [email protected]. Questions or comments sent via the 
Internet as attached electronic files must be formatted in Microsoft 
Word 97 for Windows or ASCII text.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-28-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. 2002-NM-28-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On May 24, 1989, the FAA issued AD 89-12-07, amendment 39-6232 (54 
FR 24161, June 6, 1989), applicable to all Boeing Model 747 series 
airplanes, to require periodic inspections and cleaning of the cavity 
aft of the wing center section. The requirements of that AD are 
intended to prevent ice accumulation in the aileron control system 
which could result in reduced lateral control capability.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 89-12-07, we have received several reports 
indicating ice accumulation on the lateral flight control cables in the 
wheel well of the main landing gear (MLG) on certain Model 747 series 
airplanes during flight. The ice buildup was attributed to debris 
blocking the drainage system for the canted pressure deck area, which 
caused water accumulation in the canted pressure deck. The accumulation 
of water also caused excessive corrosion of the upper skin of the wing 
center section and the

[[Page 63857]]

rear spar. Cabin pressurization caused the water to enter the wheel 
well of the MLG and solidify during flight. Such ice accumulation could 
restrict or jam control cable movement, resulting in loss of 
controllability of the airplane.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Alert Service Bulletin 747-
51A2057, dated February 21, 2002, which describes procedures for 
repetitive tests and inspections for discrepancies of the drainage 
system for the canted pressure deck located in the wheel wells of the 
MLG in the left and right wings; and corrective actions, if necessary; 
as follows:
    [sbull] Work Package 1 describes procedures for repetitive testing 
of the drainage system of the canted pressure deck for proper drainage. 
The test includes a visual inspection of the external drains, reducer, 
and drain lines for discrepancies. The discrepancies include damage, 
holes, signs of frozen water, and signs of blockage (3 to 5 pounds per 
square inch (PSI) compressed air is sent through the drain line to 
check for blockage). The corrective actions include cleaning the drain 
system to remove blockage if the air does not flow freely, and 
replacing any damaged drain line with a new drain line. The procedures 
also specify contacting the manufacturer for repair instructions for 
damaged drain lines.
    [sbull] Work Package 2 describes procedures for repetitive cleaning 
and inspecting of the canted pressure deck drainage system as shown in 
the Boeing 747 Airplane Maintenance Manual.
    [sbull] Work Package 3 describes procedures for repetitive 
inspections of the canted pressure deck for discrepancies (loose or 
missing fasteners; loose, missing, or cracked sealant; and leak paths). 
The corrective actions include replacing any loose or missing fastener, 
or loose, missing, or cracked sealant; and repair of any leak found. 
For other discrepancies, the procedures specify contacting the 
manufacturer for repair instructions.
    [sbull] Work Package 4 describes procedures for repetitive cabin 
pressurization tests to check for leaks in the canted pressure deck, 
and repair of any leak found.
    Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 89-12-07 to continue to require periodic 
inspections and cleaning of the drainage system cavity of the canted 
pressure deck, aft of the wing center section. This new action would 
add repetitive tests and inspections for discrepancies of the drainage 
system of the canted pressure deck located in the wheel wells of the 
MLG of the left and right wings; and corrective actions, if necessary. 
The new actions would terminate the requirements of the existing AD. 
The actions would be required to be accomplished in accordance with the 
service bulletin described previously, except as discussed below.

Difference Between Service Information and Proposed Rule

    Although the service bulletin specifies that the manufacturer may 
be contacted for disposition of certain repairs, this proposed AD would 
require such repairs to be accomplished per a method approved by us, 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 Aircraft Certification Office, to 
make such findings.

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 would be affected by this proposed AD.
    It would take approximately 1 work hour per airplane to accomplish 
the actions that are currently 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 would 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 proposed 
by this AD on U.S. operators is estimated to be $183,600, or $720 per 
airplane, per cycle.
    It would 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 proposed by this AD on U.S. operators is 
estimated to be $61,200, or $240 per airplane, per inspection cycle.
    It would 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 proposed 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 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

[[Page 63858]]

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 39-6232 (54 FR 
24161, June 6, 1989), and by adding a new airworthiness directive (AD), 
to read as follows:

Boeing: 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 (f)(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 
due to water entering the wheel well of the main 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 of the Drainage System/Corrective Action

    (b) Within 18 months after the effective date of this AD, do the 
actions required by paragraphs (b)(1), (b)(2), and (b)(3) of this 
AD, as applicable, per the Work Instructions of Boeing Alert Service 
Bulletin 747-51A2057, dated February 21, 2002.
    (1) Do a test (including a general visual inspection of the 
external drains, reducer, and drain lines, and sending 3 to 5 pounds 
per square inch (PSI) 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 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 (e) of this AD: If any 
discrepancy is found during any inspection or test required by 
paragraphs (b)(1) and (b)(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

    (c) Within 36 months after the effective date 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 repair of any leak found) 
per the service bulletin; except as required by paragraph (e) 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.''

Repetitive Cabin Pressurization Tests/Corrective Action

    (d) Within 72 months after the effective date 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 (e) of this AD. Repeat the cabin 
pressurization test at least every 72 months.

Corrective Action per Seattle Aircraft Certification Office (ACO)

    (e) 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

    (f)(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 (b)(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

    (g) 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 October 8, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-26203 Filed 10-15-02; 8:45 am]
BILLING CODE 4910-13-P