[Federal Register: December 16, 2004 (Volume 69, Number 241)]
[Proposed Rules]               
[Page 75267-75270]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16de04-13]                         

========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

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.

========================================================================



[[Page 75267]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19865; Directorate Identifier 2003-NM-242-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747, 757, 767 and 777 
Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for certain Boeing Model 747, 757, 767, and 777 series 
airplanes. That AD currently requires modifying certain drip shields 
located on the flight deck, and follow-on actions. This proposed AD 
would remove certain airplanes that are included in the applicability 
statement of the existing AD, and would require modifying additional 
drip shields on the flight deck of certain other airplanes. This 
proposed AD is prompted by a determination that certain airplanes have 
drip shields that are not adequately resistant to fire. We are 
proposing this AD to prevent potential ignition of the moisture barrier 
cover of the drip shield, which could propagate a small fire that 
results from an electrical arc, leading to a larger fire.

DATES: We must receive comments on this proposed AD by January 31, 
2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 

the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov
 and follow the instructions for sending your 

comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or at the Docket Management Facility, U.S. 

Department of Transportation, 400 Seventh Street SW., Room PL-401, on 
the plaza level of the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT:
    Technical information: Patrick Gillespie, Aerospace Engineer, Cabin 
Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 917-6429; fax (425) 917-6590.
    Plain language information: Marcia Walters, marcia.walters@faa.gov.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

    The FAA has implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, new AD actions are posted on DMS 
and assigned a docket number. We track each action and assign a 
corresponding directorate identifier. The DMS AD docket number is in 
the form ``Docket No. FAA-2004-99999.'' The Transport Airplane 
Directorate identifier is in the form ``Directorate Identifier 2004-NM-
999-AD.'' Each DMS AD docket also lists the directorate identifier 
(``Old Docket Number'') as a cross-reference for searching purposes.

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-19865; 
Directorate Identifier 2003-NM-242-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will 

also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of our 
docket Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You can review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.

    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You can get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.Examining
 the Docket


    You can examine the AD docket on the Internet at http://dms.dot.gov
, or in person at the Docket Management Facility office 

between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

Discussion

    On December 20, 2000, we issued AD 2000-26-04, amendment 39-12054 
(65 FR 82901, December 29, 2000), for certain Boeing Model 747, 757, 
767, and 777 series airplanes. That AD requires modification of certain 
drip shields located on the flight deck, and follow-on actions. That AD 
was prompted by a report that, on certain Boeing Model 747, 757, 767, 
and 777 series airplanes, the airplane manufacturer found some drip 
shields assembled with the

[[Page 75268]]

moisture barrier cover bonded to the insulation and multiple insulation 
layers bonded together using a non-flame-resistant adhesive. We issued 
that AD to prevent potential ignition of the moisture barrier cover of 
the drip shield, which could propagate a small fire that results from 
an electrical arc, leading to a larger fire.

Actions Since Existing AD Was Issued

    Since we issued AD 2000-26-04, the airplane manufacturer has 
determined that additional Model 757-200, -200CB, and -200PF series 
airplanes in certain configurations have drip shields that were not 
fire-blocked from potential ignition sources.
    Also, the airplane manufacturer has sampled and tested drip shield 
material on certain Model 747 and 767 series airplanes, and has 
determined that airplanes within certain line number ranges have 
compliant drip shields. Neither further testing nor installation of 
fire blocks is necessary on airplanes within these line number ranges. 
As a result, we estimate that approximately 550 Model 747 series 
airplanes and 470 Model 767 series airplanes, worldwide, will no longer 
be subject to the existing requirements.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 757-25-0226, Revision 3, 
dated September 2, 2004. (AD 2000-26-04 refers to the original issue of 
that service bulletin, dated July 3, 2000, as the acceptable source of 
service information for doing the required actions on certain Model 
757-200, -200CB, and -200PF series airplanes.) Revision 3 of the 
service bulletin describes procedures for modifying certain drip 
shields on the flight deck by installing fire blocks in areas where the 
drip shield is exposed to potential ignition sources. The procedures in 
Revision 3 of the service bulletin are substantially similar to those 
in Revision 2 of the service bulletin, dated October 31, 2002. However, 
Revision 2 differs from the original issue of the service bulletin in 
that Revision 2 adds procedures for installing fire blocks above 
windows number 2 and 3 on the flight deck on certain airplanes. 
Revision 2 also clarifies certain other procedures and corrects a part 
number of a washer that is used with a rivet to attach fire blocks to 
the drip shields. We have determined that accomplishment of the actions 
specified in Revision 3 of the service information will adequately 
address the unsafe condition.
    We have also reviewed Boeing Service Bulletins 747-25-3253, 
Revision 3, dated September 4, 2003; and 767-25-0290, Revision 4, dated 
October 28, 2004. (AD 2000-26-04 refers to the original issues of these 
service bulletins, both dated June 29, 2000, as the acceptable sources 
of service information for doing the required actions on affected Model 
747 and 767 series airplanes.) Service bulletins 747-25-3253, Revision 
3, and 767-25-0290, Revision 4, describe procedures that are similar to 
those in the original issue of those service bulletins. The latest 
revisions include a revised effectivity listing (but don't add any 
airplanes on which work is required) and clarify certain procedures.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. Therefore, we are proposing this AD, which 
would supersede AD 2000-26-04. This proposed AD would continue to 
require modifying certain drip shields on the flight deck, and related 
investigative and other specified actions. This proposed AD would 
remove certain Model 747 and Model 767 series airplanes from the 
applicability statement, and would require modifying additional drip 
shields on the flight deck on certain Model 757-200, -200CB, and -200PF 
series airplanes. This proposed AD would require you to use the service 
information described previously to perform these actions, except as 
discussed under ``Difference Between the Proposed AD and Service 
Information.''

Difference Between the Proposed AD and Service Information

    We have revised the applicability stated in paragraph (c) of this 
proposed AD to state that the requirements of this AD apply to Model 
747 series airplanes having line numbers (L/Ns) 1 through 299 inclusive 
and 951 through 1234 inclusive (except L/Ns 292, 296, 297, 1174, and 
1216), and Model 767 series airplanes having L/Ns 470 through 768 
(except L/N 758). This applicability doesn't directly correspond to the 
effectivity listing of Boeing Service Bulletins 747-25-3253, Revision 
3, and 767-25-0290, Revision 4. Those service bulletins state that no 
action is necessary on airplanes in Group 3 of Boeing Service Bulletin 
747-25-3253, Revision 3, and in Group 1 of Boeing Service Bulletin 767-
25-0290, Revision 4. However, instructions for airplanes in those 
groups have been included in the service bulletin for the convenience 
of affected operators, so those airplanes are included in the 
effectivity listing. Because no action is necessary for those 
airplanes, we have removed the airplanes in those groups from the 
applicability stated in paragraph (c) of this AD.

Changes to Existing AD

    This proposed AD would retain all requirements of AD 2000-26-04. 
Since AD 2000-26-04 was issued, the AD format has been revised, and 
certain paragraphs have been rearranged. As a result, the corresponding 
paragraph identifiers have changed in this proposed AD, as listed in 
the following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
                                           Corresponding  requirement in
      Requirement in AD  2000-26-04              this proposed  AD
------------------------------------------------------------------------
Paragraph (a)...........................  Paragraph (f).
Paragraph (b)...........................  Paragraph (g).
Paragraph (c)...........................  Paragraph (h).
------------------------------------------------------------------------

    Also, we have revised the ``Optional Sampling'' provision in 
paragraph (h) of this AD. We changed the service bulletin reference for 
Model 747 series airplanes from the original issue to Revision 3 of 
Boeing Service Bulletins 747-25-3253. As explained under ``Difference 
Between the Proposed AD and Service Information,'' Boeing has moved 
certain airplanes on which no action is necessary from Group 1 to Group 
3 in Revision 3 of the service bulletin. We have also removed the 
reference to Model 767 series airplanes listed in Group 1 of Boeing 
Service Bulletin 767-25-0290. Boeing doesn't need any more sampling 
data from these airplanes.

Costs of Compliance

    This proposed AD would affect about 2,222 airplanes worldwide. The 
following table provides the estimated costs for U.S. operators to 
comply with the actions that are required by AD 2000-26-04 and retained 
in this proposed AD. The average labor rate is $65 per work hour.

[[Page 75269]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                         U.S.-                                                         Maximum
                Model                  registered   Work hours   Labor cost  Parts cost (estimated)   fleet cost
                                       airplanes   (estimated)  (estimated)                          (estimated)
----------------------------------------------------------------------------------------------------------------
747.................................          105           39       $2,535  $2,300 to $3,500......     $633,675
757.................................          491           26        1,690  1,700.................    1,664,490
767.................................          140           17        1,105  2,300.................      476,700
777.................................           56            3          195  1,700.................      106,120
----------------------------------------------------------------------------------------------------------------

    For Model 747 series airplanes listed in Group 1 in Boeing Service 
Bulletin 747-25-3253, Revision 3, in lieu of doing the modification of 
the drip shields, this proposed AD provides an option to take samples 
of the drip shields to determine if the modification is necessary. 
Therefore, the estimated costs above may be reduced if some airplanes 
do not need the modification. It would take approximately 18 work hours 
to do the sampling, at an average labor rate of $65 per work hour. 
Based on these figures, the cost impact of the sampling is estimated to 
be $1,170 per sampled airplane.
    As many as 491 U.S.-registered Model 757-200, -200CB, and -200PF 
series airplanes may be subject to the new proposed actions. These new 
actions would take about 8 additional work hours per airplane, at an 
average labor rate of $65 per work hour. Required parts would cost an 
additional $160 per airplane (for a total parts cost of $1,860). Based 
on these figures, the estimated cost of the new actions specified in 
this proposed AD for U.S. operators of affected airplanes is up to an 
additional $333,880 or $680 per airplane.

Authority for This Rulemaking

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. Subtitle I, Section 106, 
describes the authority of the FAA Administrator. Subtitle VII, 
Aviation Programs describes in more detail the scope of the agency's 
authority.
    This rulemaking is promulgated under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, the FAA is charged with promoting 
safety flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
proposed AD.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by removing amendment 39-12054 (65 FR 
82901, December 29, 2000), and adding the following new airworthiness 
directive (AD):

Boeing: Docket No. FAA-2004-19865; Directorate Identifier 2003-NM-
242-AD.

Comments Due Date

    (a) The Federal Aviation Administration must receive comments on 
this airworthiness directive (AD) action by January 31, 2005.

Affected ADs

    (b) This AD supersedes AD 2000-26-04, amendment 39-12054 (65 FR 
82901, December 29, 2000).

Applicability

    (c) This AD applies to Model 747, 757, 767, and 777 series 
airplanes having the line numbers (L/Ns) listed in Table 1 of this 
AD; certificated in any category.

                                             Table 1.--Applicability
----------------------------------------------------------------------------------------------------------------
              Model                         Affected L/Ns                            Except L/Ns
----------------------------------------------------------------------------------------------------------------
747.............................  1 through 299 inclusive and 951   292, 296, 297, 1174, 1216.
                                   through 1234 inclusive.
757.............................  2 through 895 inclusive.........  870, 886, 894.
767.............................  470 through 768 inclusive.......  758.
777.............................  2 through 254 inclusive.........  120, 219, 230, 235, 242, 245, 249.
----------------------------------------------------------------------------------------------------------------

Unsafe Condition

    (d) This AD was prompted by a determination that certain 
airplanes have drip shields that are not adequately resistant to 
fire. We are issuing this AD to prevent potential ignition of the 
moisture barrier cover of the drip shield, which could propagate a 
small fire that results from an electrical arc, leading to a larger 
fire.

[[Page 75270]]

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Requirements of AD 2000-26-04

Modification

    (f) Within 6 years after February 2, 2001 (the effective date of 
AD 2000-26-04, amendment 39-12054), accomplish paragraphs (f)(1), 
(f)(2), and (f)(3) of this AD; in accordance with Boeing Service 
Bulletin 747-25-3253, dated June 29, 2000, or Revision 3, dated 
September 4, 2003; 757-25-0226, dated July 3, 2000, or Revision 3, 
dated September 2, 2004; 757-25-0228, dated July 3, 2000; 767-25-
0290, dated June 29, 2000, or Revision 4, dated October 28, 2004; or 
777-25-0164, dated June 29, 2000; as applicable; except as provided 
by paragraph (g) of this AD. For Model 757-200, -200CB, and -200PF 
series airplanes subject to Boeing Service Bulletin 757-25-0226: As 
of the effective date of this AD, only Revision 3 of the service 
bulletin may be used. For Model 747 and 767 series airplanes: As of 
the effective date of this AD, only Boeing Service Bulletin 747-25-
3253, Revision 3, or 767-25-0290, Revision 4, as applicable, may be 
used.
    (1) Modify drip shields located on the flight deck by installing 
fire blocks.
    (2) Prior to further flight following accomplishment of 
paragraph (f)(1) of this AD, perform a functional test of any system 
disturbed by the modification, in accordance with the applicable 
service bulletin or the Airplane Maintenance Manual (AMM), as 
applicable. If any functional test fails, prior to further flight, 
isolate the fault, correct the discrepancy in accordance with the 
applicable AMM, and repeat the failed test until it is successfully 
accomplished.
    (3) Prior to further flight following the accomplishment of 
paragraphs (f)(1) and (f)(2) of this AD, install placards on all 
modified drip shields.
    (g) If any wires or equipment are installed on the outboard 
surface of the drip shield (that is, between the drip shield and the 
airplane structure), modify that area in accordance with a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA.

Optional Sampling (Certain Model 747 Series Airplanes)

    (h) For Model 747 series airplanes listed in Group 1 in Boeing 
Service Bulletin 747-25-3253, Revision 3, dated September 4, 2003: 
In lieu of accomplishing paragraph (f) of this AD, within 6 years 
after February 2, 2001, collect samples of the insulation and 
adhesive of the drip shields, and submit the samples to the 
manufacturer for testing, in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 747-25-3253, dated June 29, 
2000, or Revision 3, dated September 4, 2003. After the effective 
date of this AD, only Revision 3 may be used.
    (1) If the test on all samples is positive, no further action is 
required by this AD.
    (2) If the test on any sample is negative, accomplish paragraph 
(f) of this AD before the compliance time specified in that 
paragraph.

New Requirements of This AD

Model 757-200, -200CB -200PF Series Airplanes Previously Modified

    (i) For Model 757-200, -200CB, and -200PF series airplanes that 
were modified before the effective date of this AD in accordance 
with Boeing Service Bulletin 757-25-0226, dated July 3, 2000: Within 
6 years after the effective date of this AD, modify drip shields 
located above windows number 2 and 3 on the flight deck by 
installing fire blocks, in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 757-25-0226, Revision 3, 
dated September 2, 2004; except as provided by paragraph (g) of this 
AD. After the modification, do the actions required by paragraph 
(f)(2) and (f)(3) of this AD as these actions apply to the drip 
shields modified in accordance with this paragraph.

Previously Accomplished Actions

    (j) Modifying the drip shields before the effective date of this 
AD in accordance with the applicable service bulletin specified in 
paragraph (j)(1) or (j)(2) of this AD is acceptable for compliance 
with the corresponding requirements of paragraphs (f) and (i) of 
this AD, as applicable.
    (1) For Model 757-200, -200CB, and -200PF series airplanes: 
Boeing Service Bulletin 757-25-0226, Revision 2, dated October 31, 
2002.
    (2) For Model 767 series airplanes: Boeing Service Bulletin 767-
25-0290, Revision 3, dated June 26, 2003.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle ACO, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19.
    (2) Except for Model 757-200, -200CB, and -200PF series 
airplanes listed in Boeing Service Bulletin 757-25-0226, Revision 3, 
dated September 2, 2004: Alternative methods of compliance, approved 
previously in accordance with AD 2000-26-04, amendment 39-12054, are 
approved as alternative methods of compliance with this AD.

    Issued in Renton, Washington, on December 6, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-27503 Filed 12-15-04; 8:45 am]

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