[Federal Register Volume 68, Number 232 (Wednesday, December 3, 2003)]
[Proposed Rules]
[Pages 67616-67618]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-30115]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-93-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400 and 747-400D 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 747-400 and 
747-400D series airplanes. This proposal would require a detailed 
inspection of the fire extinguishing system tube and clamp for correct 
installation or a repetitive pressure test of the fire extinguishing 
system tube for leakage, and corrective action, if necessary. This 
action is necessary to prevent a chafed hole in the fire extinguishing 
system tube of the aft cargo compartment, which could result in a lack 
of fire extinguishing agent and consequent uncontained fire in the aft 
cargo compartment. This action is intended to address the identified 
unsafe condition.

DATES: Comments must be received by January 20, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-93-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. 2003-NM-93-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 or 2000 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: Barbara Mudrovich, Aerospace Engineer, 
Cabin Safety & Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 917-6477; fax (425) 917-6590.

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

[[Page 67617]]

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 200-NM-93-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. 2003-NM-93-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report of a chafed hole in the fire 
extinguishing system tube of the aft cargo compartment on a Boeing 
Model 747-400 series airplane. During production, the tube was 
installed incorrectly with the bend down and clamps upside down, which 
can cause the tube to chafe against a stiffener on the air conditioning 
duct located below the tube. If the discharge tube has a chafed hole, 
there may not be a sufficient amount of fire extinguishing agent to 
extinguish a fire in the aft cargo compartment. This condition, if not 
corrected, could result in an uncontained fire in the aft cargo 
compartment.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 747-
26A2270, Revision 1, dated January 16, 2003, which describes the 
following procedures:
    [sbull] Performing a detailed inspection of the fire extinguishing 
system tube and clamps for correct installation, either using an 
inspection hole and boroscope or with the floor panel removed;
    [sbull] Performing a repetitive pressure test of the fire 
extinguishing system tube for leakage; and
    [sbull] Performing corrective actions, if necessary.
    The corrective actions include the following procedures:
    [sbull] Performing a detailed inspection of the fire extinguishing 
system tube for chafing/damage;
    [sbull] Replacing the fire extinguishing system tube with a new 
tube;
    [sbull] Repairing the fire extinguishing system tube; and
    [sbull] Installing the new or repaired fire extinguishing system 
tube.
    Accomplishment of the Part 1--Option 1 or 2 inspections or the Part 
2 inspection and repair/replacement in the service bulletin constitutes 
terminating action for the repetitive pressure test. 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 require accomplishment of the actions specified in 
the service bulletin described previously.

Cost Impact

    There are approximately 416 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 44 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
1 work hour per airplane to accomplish the proposed inspection or 
pressure test, and that the average labor rate is $65 per work hour. 
Based on these figures, the cost impact of the proposed AD on U.S. 
operators is estimated to be $2,860, or $65 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 proposed 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:

Boeing: Docket 2003-NM-93-AD.

    Applicability: Model 747-400 and 747-400D series airplanes, as 
listed in Boeing Service Bulletin 747-26A2270, Revision 1, dated 
January 16, 2003; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a chafed hole in the fire extinguishing system tube 
of the aft cargo compartment, which could result in a lack of

[[Page 67618]]

fire extinguishing agent and consequent uncontained fire in the aft 
cargo compartment, accomplish the following:

Service Bulletin References

    (a) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing Service Bulletin 747-26A2270, 
Revision 1, dated January 16, 2003.

Inspection/Pressure Test

    (b) Within 6,500 flight hours or 18 months after the effective 
date of this AD, whichever occurs first, perform the detailed 
inspection specified in paragraph (b)(1) of this AD or the pressure 
test specified in paragraph (b)(2) of this AD.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

    (1) Perform a detailed inspection of the fire extinguishing 
system tube and clamps for correct installation, either using an 
inspection hole and boroscope or with the floor panel removed, per 
the service bulletin.
    (i) If the fire extinguishing system tube is installed 
correctly, no further action is required by this AD.
    (ii) If the fire extinguishing system tube is installed 
incorrectly, prior to further flight, do the actions specified in 
paragraph (c) of this AD.
    (2) Perform a pressure test of the fire extinguishing system 
tube to check for leakage of the fire extinguishing agent per the 
service bulletin.
    (i) If leakage is not found, repeat the pressure test thereafter 
at intervals not to exceed 6,500 flight hours or 18 months, 
whichever occurs first, until the actions specified in paragraph 
(b)(1) or (c) of this AD have been done.
    (ii) If any leakage is found, prior to further flight, do the 
actions specified in paragraph (c) of this AD.

Removal and Installation/Repair/Replace

    (c) Remove the fire extinguishing system tube and do the actions 
in paragraph (c)(1) or (c)(2) of this AD, as applicable.
    (1) If, during the detailed inspection specified in paragraph 
(b)(1) of this AD, the fire extinguishing system tube was found to 
be installed incorrectly: Prior to further flight, perform a 
detailed inspection of the fire extinguishing system tube for 
chafing/damage per the service bulletin.
    (i) If no chafing/damage is found, prior to further flight, 
install the existing fire extinguishing system tube per Figure 3 of 
the service bulletin.
    (ii) If any chafing/damage is found, prior to further flight, 
replace the fire extinguishing system tube with a new tube or repair 
the fire extinguishing system tube, per the service bulletin, and 
install the new or repaired tube per Figure 3 of the service 
bulletin.
    (2) If, during the pressure test required by paragraph (b)(2) of 
this AD, leakage was found: Prior to further flight, replace the 
fire extinguishing system tube with a new tube or repair the fire 
extinguishing system tube, per the service bulletin, and install the 
new or repaired tube per Figure 3 of the service bulletin.

Terminating Action

    (d) Accomplishment of the actions specified in paragraph (b)(1) 
or (c) of this AD constitutes terminating action for the 
requirements of this AD.

Actions Accomplished Per Previous Issue of Service Bulletin

    (e) Inspections, repetitive tests and corrective actions 
accomplished before the effective date of this AD per Boeing Alert 
Service Bulletin 747-26A2270, dated May 8, 2002, are considered 
acceptable for compliance with the corresponding action specified in 
this AD.

Alternative Methods of Compliance

    (f) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

    Issued in Renton, Washington, on November 26, 2003.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-30115 Filed 12-2-03; 8:45 am]
BILLING CODE 4910-13-P