AD 2004-09-10

[Federal Register Volume 69, Number 84 (Friday, April 30, 2004)]
[Rules and Regulations]
[Pages 23647-23650]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 04-9592]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-341-AD; Amendment 39-13599; AD 2004-09-10]
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 adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 747 series airplanes. This AD 
requires a one-time inspection of the potable water and drain lines in 
the forward and aft cargo compartments for indications of overheating 
of the heater tape, exposed foam insulation, missing or damaged 
protective tape, or debris around the potable water fill and drain 
lines; and corrective action, if necessary. This action is necessary to 
prevent overheating of the heater tape on potable water fill and drain 
lines, which may ignite accumulated debris or contaminants on or near 
the potable water fill and drain lines, resulting in a fire in the 
airplane. This action is intended to address the identified unsafe 
condition.

DATES: Effective June 4, 2004.
    The incorporation by reference of a certain publication listed in 
the regulations is approved by the Director of the Federal Register as 
of June 4, 2004.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington

[[Page 23648]]

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: Donald Eiford, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6465; fax (425) 917-6590.

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 certain Boeing Model 747 series 
airplanes was published in the Federal Register on April 29, 2003 (68 
FR 22639). That action proposed to require a one-time inspection of the 
potable water and drain lines in the forward and aft cargo compartments 
for indications of overheating of the heater tape, exposed foam 
insulation, missing or damaged protective tape, or debris around the 
potable water fill and drain lines; and corrective action, if 
necessary.

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 Allow Deactivation of Heater Tape Prior to Further Flight

    Three commenters request that paragraph (b)(1) of the notice of 
proposed rulemaking (NPRM) be changed so that, after the inspection 
required by paragraph (b)(1), either replacement or deactivation of the 
heater tape prior to further flight is allowed. The commenters note 
that Figure 1 of the service bulletin states that operators may 
deactivate the heater tape prior to further flight, and replace the 
heater tape when materials, time, and manpower are available.
    One of the commenters states that, due to the proposed 90-day 
compliance time in the NPRM, it is important not to ground airplanes 
and to give operators the flexibility to accomplish the heater tape 
replacement at a more opportune time. Another commenter suggests that a 
compliance time not to exceed 90 days after the completion of the 
inspection required by paragraph (b)(1) of the NPRM be allowed so 
operators can schedule the heater tape replacement at a convenient 
time.
    We agree with the commenters' requests to allow deactivation of the 
heater tape prior to further flight. We have determined that this 
action will not affect safety because once the heater tape is 
deactivated it cannot become overheated. Paragraph (b)(1) of this final 
rule has been changed accordingly.
    We also agree with the commenter's request for a compliance time of 
within 90 days after the date of the inspection required by paragraph 
(b)(1) of this AD for operators to replace the heater tape. We find 
that this is an acceptable amount of time because, as previously 
mentioned, once the heater tape is deactivated it cannot become 
overheated. Paragraph (b)(1) of this final rule has been changed 
accordingly.

Request To Change Wording of Paragraph (b)(2)

    One commenter requests either removing the words ``prior to further 
flight'' or changing the wording of paragraph (b)(2). This paragraph 
requires that any exposed foam insulation over the heater tape be 
covered with a continuous wrap of protective tape, and replacement of 
any missing or damaged protective tape over the heater tape prior to 
further flight. We infer that the basis for this request is to give 
operators the flexibility to accomplish the actions required in 
paragraph (b)(2) of the AD at a more convenient time.
    We agree with the commenter's request to change the wording of 
paragraph (b)(2) of this AD. We will include a compliance time of 
within 90 days after the date of the inspection required by paragraph 
(b)(2) for operators to install or replace protective wrap in areas 
where the wrap is missing or damaged. We find that this compliance time 
will not compromise safety because the protective tape is a 
preventative measure and is not directly related to overheating of the 
heater tape. Paragraph (b)(2) of this final rule has been changed 
accordingly.

Request To Allow Deactivation of the Heater Tape for the Potable Water 
System Per the Operator's Minimum Equipment List (MEL)

    One commenter requests the option to deactivate the heater tape for 
the potable water system per the procedures in the applicable MEL, 
instead of following the procedures specified in Figure 1 of Boeing 
Alert Service Bulletin 747-30A2079, dated December 12, 2002. The 
commenter implies that, since the MEL does not require capping and 
stowing the wires to the heater tape as the service bulletin does, the 
MEL procedure is more convenient for an operator to accomplish.
    We agree with the commenter's request to allow deactivation of the 
heater tape per the procedures in the applicable MEL as an alternative 
to accomplishing the procedures specified in the service bulletin. We 
have determined that this change will not compromise safety. Paragraph 
(b)(1) of this final rule has been changed accordingly.

Request To Clarify Meaning of ``Visually Accessible''

    One commenter requests that the term ``visually accessible'' used 
in paragraphs (a) and (b) of the NPRM be defined as ``only those areas 
that can be visually accessed and do not require the disassembly of 
cargo wall liners.'' The commenter states that Boeing Alert Service 
Bulletin 747-30A2079, dated December 12, 2002, includes the inspection 
of heater tapes that are located behind cargo wall liners. The areas 
located behind the cargo wall liners are not visually accessible and 
are not susceptible to debris collection, therefore they should not be 
required to be inspected.
    We agree with the commenter that the term ``visually accessible'' 
should be clarified. The intent of the NPRM was to require inspection 
of only the visually accessible areas below the cargo floor in the 
forward and aft cargo compartments. Since publication of the NPRM, 
Boeing has issued and the FAA has approved Revision 1 of Boeing Service 
Bulletin 747-30A2079, dated October 16, 2003. Revision 1 of the service 
bulletin deletes the inspection of areas behind the cargo wall liners 
and specifies that only areas not covered by floor panel or sidewall 
panels should be inspected. The term ``visually accessible'' has been 
deleted from paragraphs (a) and (b) of this final rule and replaced 
with ``areas not covered by floor panels or sidewall panels.'' As a 
result of this change, Note 2 in the body of the NPRM has been omitted 
from this final rule. Note 2 stated ``The inspection of potable water 
and drain lines in areas not covered by floor panels or sidewall panels 
areas does not require removal of floor panels.'' The subsequent Notes 
in this final rule have been renumbered accordingly.

Request for Distinction Between Fiberglass Insulation and Foam 
Insulation

    One commenter requests that a distinction be made between the types 
of insulation used in the cargo compartment. The commenter states that 
the wording of one of the caution

[[Page 23649]]

notes in Boeing Alert Service Bulletin 747-30A2079, dated December 12, 
2002, specifies ``a minimum clearance of one inch (2.54 centimeters) 
between the heater tape and any insulation.'' The commenter states that 
some airplanes may have foam insulation surrounding the heater tape, 
and that the one-inch clearance should be between the heater tape and 
the floor or fuselage fiberglass insulation, not the foam insulation 
surrounding the potable water lines.
    We agree with the commenter's request to make a distinction between 
the types of insulation located in the cargo compartment. It was not 
the intent of the NPRM or the service bulletin to require a one-inch 
separation between the foam insulation and the heater tape, especially 
since the foam insulation was designed to be installed directly over 
the heater tape. Since publication of the NPRM, Boeing has issued and 
the FAA has approved Revision 1 of Boeing Service Bulletin 747-30A2079, 
dated October 16, 2003. Revision 1 of the service bulletin deletes the 
caution note cited by the commenter, which should eliminate the 
confusion regarding the need for clearance between the heater tape and 
foam insulation. Revision 1 will be cited in this final rule as the 
appropriate source of service information; however, paragraph (d) of 
this AD gives credit to operators who accomplished the actions required 
by this AD, before the effective date of this AD, per Boeing Alert 
Service Bulletin 747-30A2079, dated December 12, 2002.

Request To Clarify That Foam Insulation Should Only Be Removed If It 
Exhibits Signs of Overheating

    The same commenter also requests that the AD specify that foam 
insulation should only be removed if it exhibits signs of overheating, 
or that the AD reference a subsequent service bulletin revision which 
contains this information. One of the caution notes in Boeing Alert 
Service Bulletin 747-30A2079, dated December 12, 2002, implies that if 
foam insulation is installed, it must be removed to verify heater tape 
pitch. The work instructions in Figure 1 of the service bulletin only 
gives procedures for inspection of the heater tape and foam insulation 
for signs of overheating. The work instructions do not specify that the 
foam insulation should be removed to verify heater tape pitch.
    We agree with the commenter's request to reference a subsequent 
revision of the service bulletin. It was not the intent of the NPRM to 
require removal of undamaged foam insulation to verify the installation 
pitch of the heater tape. As previously stated, the caution note, which 
may have caused confusion regarding the intent of the service bulletin, 
was deleted from Revision 1 of Boeing Service Bulletin 747-30A2079, 
dated October 16, 2003. Revision 1 will be cited in this final rule as 
the appropriate source of service information.

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.

Changes to 14 CFR Part 39/Effect on the AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance. However, for clarity and consistency in this final rule, we 
have retained the language of the NPRM regarding that material.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Change to Labor Rate Estimate

    After the NPRM was issued, we reviewed the figures we use to 
calculate the labor rate to do the required actions. To account for 
various inflationary costs in the airline industry, we find it 
appropriate to increase the labor rate used in these calculations from 
$60 per work hour to $65 per work hour. The economic impact 
information, below, has been revised to reflect this increase in the 
specified hourly labor rate.

Cost Impact

    There are approximately 1,129 airplanes (968 passenger and 161 
freighter) of the affected design in the worldwide fleet. We estimate 
that 250 airplanes of U.S. registry will be affected by this AD. We 
provide the following cost estimates associated with this AD:

                                                 Cost Estimates
                                                  [In dollars]
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                                                       Hourly
            Type of airplane                 Work      labor      Parts      Cost per    Number of    Fleet cost
                                            hours       rate       cost      airplane    airplanes
----------------------------------------------------------------------------------------------------------------
Freighter...............................         10         65          0          650           35       22,750
Passenger...............................         20         65          0        1,300          215      279,500
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    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

[[Page 23650]]

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:

2004-09-10 Boeing: Amendment 39-13599. Docket 2002-NM-341-AD.

    Applicability: Model 747 series airplanes, certificated in any 
category, with lower cargo floors (floors in the lower cargo areas) 
that are not fully enclosed. A fully enclosed cargo floor is a floor 
with panels installed between all roller trays in the cargo 
compartment. A cargo floor that is not fully enclosed is a floor 
without panels installed between all roller trays in the cargo 
compartment.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent overheating of the heater tape on potable water fill 
and drain lines, which may ignite accumulated debris or contaminants 
on or near the potable water fill and drain lines, resulting in a 
fire in the airplane, accomplish the following:

Debris Removal

    (a) At the later of the times specified in paragraphs (a)(1) and 
(a)(2) of this AD: Perform a one-time general visual inspection for 
foreign object debris (FOD) and contamination on or near potable 
water and drain lines located below the cargo floor in the forward 
and aft cargo compartments, in areas not covered by floor panels or 
sidewall panels. Do the inspection in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 747-30A2079, 
Revision 1, dated October 16, 2003. Remove any FOD or contamination 
observed on or near the potable water or drain lines prior to 
further flight in accordance with the service bulletin.
    (1) Inspect within 18 months since the date of issuance of the 
original Airworthiness Certificate or within 18 months since the 
date of issuance of the Export Certificate of Airworthiness, 
whichever occurs first; or
    (2) Inspect within 90 days after the effective date of this AD.

    Note 1: 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.''

Inspection for Discrepant Heater Tape

    (b) At the applicable time specified in paragraph (c) of this 
AD: Perform a general visual inspection for discrepancies of potable 
water and drain lines located below the cargo floor in the forward 
and aft cargo compartments, in areas not covered by floor panels or 
sidewall panels, as specified in paragraphs (b)(1) and (b)(2) of 
this AD. Do the inspection in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 747-30A2079, Revision 1, 
dated October 16, 2003.
    (1) Inspect potable water and drain lines for indications of 
overheating of the heater tape, including localized darkening of 
foam insulation or protective tape. If overheating is observed: 
Prior to further flight, either replace the defective heater tape, 
removing floor panels as necessary, in accordance with the service 
bulletin; deactivate the heater tape in accordance with the 
provisions and limitations specified in the operator's Minimum 
Equipment List (MEL); or deactivate the heater tape in accordance 
with Figure 1 of the service bulletin. If the heater tape is 
deactivated it must be replaced within 90 days after the date of the 
inspection required by this paragraph.
    (2) Inspect potable water and drain lines for exposed foam 
insulation and missing or damaged protective tape. If exposed foam 
insulation is observed: Within 90 days after the date of the 
inspection required by this paragraph, cover the foam insulation 
with a continuous wrap of protective tape, in accordance with the 
service bulletin. If protective tape is missing or damaged: Within 
90 days after the date of the inspection required by this paragraph, 
replace the protective tape in accessible areas in accordance with 
the service bulletin. It is not necessary to remove floor panels to 
replace the protective tape.
    (c) Do the inspections required by paragraph (b) at the later of 
the times specified in paragraphs (c)(1) and (c)(2) of this AD.
    (1) Within 18 months 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 90 days after the effective date of this AD.

Credit for Actions Accomplished Previously

    (d) Actions accomplished before the effective date of this AD, 
per Boeing Alert Service Bulletin 747-30A2079, dated December 12, 
2002, are acceptable for compliance with the corresponding actions 
required by paragraphs (a) and (b) of this AD.

Alternative Methods of Compliance

    (e) 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 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, Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Incorporation by Reference

    (f) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Boeing Service Bulletin 747-30A2079, 
Revision 1, dated October 16, 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 Airplanes, PO 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

    (g) This amendment becomes effective on June 4, 2004.

    Issued in Renton, Washington, on April 20, 2004.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-9592 Filed 4-29-04; 8:45 am]
BILLING CODE 4910-13-U