[Federal Register Volume 69, Number 232 (Friday, December 3, 2004)]
[Proposed Rules]
[Pages 70204-70208]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-26664]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19796; Directorate Identifier 2004-NM-61-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, -100B, -100B SUD, 
-200B, -200C, -300, -400, and -400D Series Airplanes; and Model 747SR 
Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for certain Boeing Model 747 series airplanes. That AD 
currently requires a one-time inspection to determine the material type 
of the stop support fittings of the main entry doors (MEDs). That AD 
also currently requires repetitive detailed inspections to detect 
cracks of certain stop support fittings of the MEDs, and replacement of 
any cracked stop support fitting with a certain new stop support 
fitting. This proposed AD would add new inspections and replacement if 
necessary of the stop support fittings of MED 3, and add airplanes to 
the applicability. This proposed AD is prompted by reports of MED 3 
having certain stop support fittings which are susceptible to stress 
corrosion cracking. We are proposing this AD to detect and correct 
stress corrosion cracking of the stop support fittings of the MEDs, 
which could result in damage to the adjacent forward edge frame of the 
door and consequent loss of a MED and rapid decompression of the 
airplane.

DATES: We must receive comments on this proposed AD by January 18, 
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: Ivan Li, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98055-4056;

[[Page 70205]]

telephone (425) 917-6437; fax (425) 917-6590.
    Plain language information: Marcia Walters, [email protected].

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 written relevant data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-19796; 
Directorate Identifier 2004-NM-61-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 may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may 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 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 14, 1998, we issued AD 98-26-13, amendment 39-10954 (63 
FR 70316, December 21, 1998), for certain Boeing Model 747-100, -100B, 
-200, -200B, -200C, -300, -400, and 747SR series airplanes having line 
numbers 1 through 830 inclusive. That AD requires a one-time inspection 
to determine the material type of the stop support fittings of the main 
entry doors (MEDs). That AD also currently requires repetitive detailed 
inspections to detect cracks of certain stop support fittings of the 
MEDs, and replacement of any cracked stop support fitting with a 
certain new stop support fitting. That AD was prompted by reports that 
stress corrosion cracking was found on certain stop support fittings of 
the MEDs. We issued that AD to detect and correct stress corrosion 
cracking of the stop support fittings of the MEDs, which could lead to 
failure of the stop support fittings, consequent loss of a MED, and 
rapid decompression of the airplane.

Actions Since Existing AD Was Issued

    Since we issued AD 98-26-13, we received a report from the 
manufacturer that the new stop support fittings installed in production 
for MED 3 on airplanes after line number 830 may not have been made of 
the correct material type. In addition, the new stop support fittings 
supplied by Boeing as the replacement fitting for MED 3 may not have 
been made from the correct material type.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 747-53-
2485, dated January 8, 2004. The service bulletin describes procedures 
for performing a high frequency eddy current (HFEC) inspection to 
determine the material type of the stop support fittings of MED 3. The 
service bulletin also describes procedures for repetitive visual 
inspections to detect cracks of the stop support fittings (not made 
from 7075-T73 or 7050-T7451 material) of MED 3, and replacement of any 
cracked fitting with a new fitting made from 7075-T73 or 7050-T7451 
material. In addition, the service bulletin describes procedures for 
optional replacement of the stop support fittings of the MEDs with stop 
support fittings made from 7075-T73 or 7050-T7451 material, which would 
eliminate the need for repetitive inspections. The new stop support 
fitting is less susceptible to stress corrosion cracking.
    The FAA has reviewed Boeing Service Bulletin 747-53-2358, Revision 
1, dated April 19, 2001 (the original issue, dated August 26, 1993, is 
referenced as the appropriate source of service information for 
accomplishing AD 98-26-13). Revision 1 of the service bulletin 
describes procedures for performing an HFEC inspection to determine the 
material type of the stop support fittings of the MEDs. The service 
bulletin also describes procedures for repetitive visual inspections to 
detect cracks of the stop support fitting (not made from 7075-T73 or 
7050-T7451 material) of the MEDs, and replacement of any cracked 
fitting with a new fitting made from 7075-T73 or 7050-T7451 material. 
In addition, the service bulletin describes procedures for optional 
replacement of the stop support fittings of the MEDs with stop support 
fittings made from 7075-T73 or 7050-T7451 material, which would 
eliminate the need for repetitive inspections. The new stop support 
fitting is less susceptible to stress corrosion cracking.
    We have determined that accomplishment of the actions specified in 
the service information will adequately address the unsafe condition.

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 98-26-13. This proposed AD would continue to require 
a one-time inspection to determine the material type of the stop 
support fittings of the MEDs. This proposed AD would also continue to 
require repetitive detailed inspections to detect cracks of certain 
stop support fittings of the MEDs, and replacement of any cracked stop 
support fitting with a certain new stop support fitting. This proposed 
AD would also require new inspections and replacement if necessary of 
the stop support fittings of MED 3 and add airplanes to the 
applicability. This proposed AD would require you to use the service 
information described

[[Page 70206]]

previously to perform these actions, except as discussed under 
``Differences Between the Proposed AD and Service Bulletins.''

Differences Between the Proposed AD and Service Bulletins

    For certain airplanes, Boeing Special Attention Service Bulletin 
747-53-2485, dated January 8, 2004, specifies an inspection threshold 
of 6 years after the airplane was delivered or 18 months since the 
release of the service bulletin, whichever occurs later. However, for 
these same airplanes, paragraph (i) of the proposed AD specifies an 
inspection threshold of 72 months after the date of issuance of the 
original Airworthiness Certificate or the date of issuance of the 
original Export Certificate of Airworthiness, or 18 months after the 
effective date of the AD, whichever occurs later. This decision is 
based on our determination that the date the airplane was delivered may 
be interpreted differently by different operators. We find that our 
proposed terminology is generally understood within the industry and 
records will always exist that establish these dates with certainty.
    Whereas Boeing Service Bulletin 747-53-2358, dated August 26, 1993; 
and Boeing Service Bulletin 747-53-2358, Revision 1, dated April 19, 
2001; specify a ``visual inspection,'' the intent of the proposed AD is 
to require a ``detailed inspection.'' Additionally, a note has been 
added to the proposed AD to define that inspection.

Explanation of Change to Applicability

    We have revised the applicability of the existing AD to identify 
model designations as published in the most recent type certificate 
data sheet for the affected models. In paragraphs (f) and (g) of the 
proposed AD, the model designation ``747-100B SUD'' has been added. 
There is no increase in the number of applicable airplanes for these 
paragraphs.

Clarification of Inspection Type

    Although Boeing Special Attention Service Bulletin 747-53-2485, 
dated January 8, 2004, specifies a ``detailed visual inspection,'' this 
proposed AD requires a ``detailed inspection.''

Clarification of Service Bulletin

    Operators should also note that Boeing Service Bulletin 747-53-
2358, Revision 1, dated April 19, 2001, specifies in the ``Action'' and 
``Description'' paragraphs that you can end the repetitive inspections 
if you replace the stop support fittings with stop support fittings 
made from 7075-T73 or 7050-T7451 material. However, the Note under 
``Stop Support Fitting Replacement'' of the Work Instructions of the 
service bulletin only specifies ending repetitive inspections if you 
replace with stop support fittings made from 7075-T73. Replacing with 
stop support fittings made of 7075-T73 or 7050-T7451 material does end 
the repetitive inspections as both are less susceptible to stress 
corrosion cracking.

Change to the Number of Airplanes in the Costs of Compliance

    Operators should note that for AD 98-26-13 we estimated that there 
are about 575 airplanes of the affected design in the worldwide fleet 
and that about 164 airplanes of U.S. registry would be affected by that 
AD. However, for this proposed AD, which includes actions required by 
AD 98-26-13, we estimate that there are 814 airplanes of the affected 
design in the worldwide fleet and that 119 airplanes of U.S. registry 
would be affected by the proposed AD. The increase in the number of 
airplanes worldwide is due to the expanded applicability. The decrease 
in number of airplanes of U.S. registry may be due to a number of 
reasons such as retirement of airplanes and transfer of airplanes to 
foreign operators.

Change to Existing AD

    This proposed AD would retain all requirements of AD 98-26-13. 
Since AD 98-26-13 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 98-26-13                this proposed AD
------------------------------------------------------------------------
Paragraph (a)..........................  Paragraph (f).
Paragraph (b)..........................  Paragraph (g).
Paragraph (c)..........................  Paragraph (l).
------------------------------------------------------------------------

Costs of Compliance

    There are about 814 airplanes of the affected design in the 
worldwide fleet. There are about 119 airplanes of U.S. registry that 
would be affected by this proposed AD. The following table provides the 
estimated costs for U.S. operators to comply with this proposed AD.

                                                 Estimated Costs
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                                                                             Average
                           Action                              Work hours   labor rate     Parts       Cost per
                                                                             per hour                    door
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HFEC Inspection (required by AD 98-26-13)...................            1          $65         None          $65
Detailed Inspection as applicable (required by AD 98-26-13).            2           65         None          130
Optional Terminating Action (specified in AD 98-26-13)......          124           65      $13,000       21,060
Detailed Inspection and HFEC Inspection as applicable (new              3           65         None          195
 proposed action)...........................................
Replacement as applicable (new proposed action).............          120           65       17,724       25,524
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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 
safe 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

[[Page 70207]]

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 39-10954 (63 FR 
70316, December 21, 1998) and adding the following new airworthiness 
directive (AD):

Boeing: Docket No. FAA-2004-19796; Directorate Identifier 2004-NM-
61-AD.

Comments Due Date

    (a) The Federal Aviation Administration must receive comments on 
this airworthiness directive (AD) action by January 18, 2005.

Affected ADs

    (b) This AD supersedes AD 98-26-13, amendment 39-10954.

Applicability

    (c) This AD applies to Boeing Model 747-100, -100B, -100B SUD, -
200B, -200C, -300, -400, and -400D series airplanes; and Model 747SR 
series airplanes; having line numbers 1 through 1301 inclusive; 
certificated in any category.

Unsafe Condition

    (d) This AD was prompted by reports of main entry door (MED) 3 
having certain stop support fittings which are susceptible to stress 
corrosion cracking. We are issuing this AD to detect and correct 
stress corrosion cracking of the stop support fittings of the MEDs 
which could result in damage to the adjacent forward edge frame of 
the door and consequent loss of a MED and rapid decompression of the 
airplane.

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 98-26-13

Inspections and Corrective Action

    (f) For Model 747-100, -100B, -100B SUD, -200, -200B, -200C, -
300, -400, and 747SR series airplanes having line numbers 1 through 
830 inclusive: Within 18 months after January 25, 1999 (the 
effective date of AD 98-26-13, amendment 39-10954), perform a high 
frequency eddy current (HFEC) inspection to determine the material 
type of the stop support fittings of the MEDs, in accordance with 
the Accomplishment Instructions of Boeing Service Bulletin 747-53-
2358, dated August 26, 1993; or Boeing Service Bulletin 747-53-2358, 
Revision 1, dated April 19, 2001. Perform the inspection only at 
those locations where the material type of the stop support fittings 
is unknown, as specified in Figure 3, Table 1, of either service 
bulletin. As of the effective date of this AD, do the actions in 
accordance with Boeing Service Bulletin 747-53-2358, Revision 1, 
dated April 19, 2001.
    (1) If the fitting is made from 7075-T73 or 7050-T7451 material, 
no further action is required by this AD for that fitting; however, 
the requirements of paragraph (l) of this AD still applies.
    (2) If the fitting is not made from 7075-T73 or 7050-T7451 
material, before further flight, perform a detailed inspection to 
detect cracks of the stop support fitting of the MEDs, in accordance 
with the applicable service bulletin.

    Note 1: For the purposes of this AD, a detailed inspection is 
``an intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirrors magnifying lenses, etc. may be necessary. Surface cleaning 
and elaborate procedures may be required.''

    (i) If no crack is detected, repeat the detailed inspection 
thereafter at intervals not to exceed 36 months or 2,000 flight 
cycles, whichever occurs first.
    (ii) If any crack is detected, before further flight, replace 
the fitting with a stop support fitting made from 7075-T73 or 7050-
T7451 material, in accordance with the applicable service bulletin.
    (g) For Model 747-100, -100B, -100B SUD, -200, -200B, -200C, -
300, -400, and 747SR series airplanes having line numbers 1 through 
830 inclusive: Replacement of the stop support fitting of the MEDs 
with a stop support fitting made from 7075-T73 material, in 
accordance with Boeing Service Bulletin 747-53-2358, dated August 
26, 1993; or replacement with a stop support fitting made from 7075-
T73 or 7050-T7451 material, in accordance with Boeing Service 
Bulletin 747-53-2358, Revision 1, dated April 19, 2001; constitutes 
terminating action for the repetitive inspection requirements of 
paragraph (f) of this AD for the replaced fitting. As of the 
effective date of this AD, only Boeing Service Bulletin 747-53-2358, 
Revision 1, dated April 19, 2001, may be used.

New Requirements of This AD

Inspection for Material Type

    (h) For Model 747-100, -100B, -100B SUD, -200B, -200C, -300, -
400, and -400D series airplanes, and Model 747SR series airplanes, 
having line numbers 1 through 830 inclusive on which the actions 
specified in the Accomplishment Instructions of Boeing Service 
Bulletin 747-53-2358, dated August 26, 1993; or Boeing Service 
Bulletin 747-53-2358, Revision 1, dated April 19, 2001; have been 
done: Do the inspection specified in paragraph (h)(1) or (h)(2) of 
this AD, as applicable, at the time specified.
    (1) Except as provided by paragraph (h)(2) of this AD, if any 
stop support fitting, 2L through 6L and 2R through 6R, of MED 3, was 
replaced before the effective date of this AD: Perform a one-time 
HFEC inspection to determine the material type of the stop support 
fittings of MED 3 that were replaced, in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-53-2485, dated January 8, 2004, at the later of the 
times specified in paragraphs (h)(1)(i) and (h)(1)(ii) of this AD.
    (i) Within 72 months after the stop support fitting of MED 3 was 
replaced.
    (ii) Within 18 months after the effective date of this AD.
    (2) If any stop support fitting, 2L through 6L and 2R through 
6R, of MED 3, cannot be determined conclusively by reviewing 
airplane maintenance records that the fitting was not replaced, 
within 18 months after the effective date of this AD, perform a one-
time HFEC inspection to determine the material type of the stop 
support fitting, in accordance with the Accomplishment Instructions 
of Boeing Special Attention Service Bulletin 747-53-2485, dated 
January 8, 2004.
    (i) For airplanes having line numbers 831 through 1301 
inclusive: At the later of the times specified in paragraphs (i)(1) 
and (i)(2) of this AD, perform a one-time HFEC inspection to 
determine the material type of the stop support fittings of MED 3 in 
accordance with the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 747-53-2485, dated January 8, 2004.
    (1) Before 72 months since the date of issuance of the original 
Airworthiness Certificate or the date of issuance of the original 
Export Certificate of Airworthiness.
    (2) Within 18 months after the effective date of this AD.

No Further Action

    (j) If, during any HFEC inspection required by paragraph (h) or 
(i) of this AD, any fitting is found to be made of 7075-T73 or 7050-
T7451 material, no further action is required by this AD for that 
fitting; however, paragraph (l) of this AD still applies.

[[Page 70208]]

Initial and Repetitive Inspections for Cracking and Corrective 
Action

    (k) If, during any HFEC inspection required by paragraph (h) or 
(i) of this AD, any fitting is found not to be made of 7075-T73 or 
7050-T7451 material, before further flight, perform a detailed 
inspection for cracks of the fitting in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-53-2485, dated January 8, 2004.
    (1) If no crack is detected, repeat the detailed inspection 
specified in paragraph (k) of this AD thereafter at intervals not to 
exceed 36 months or 2,000 flight cycles, whichever comes first. 
Doing the replacement specified in paragraph (k)(2) of this AD ends 
the repetitive inspections for the replaced fitting.
    (2) If any crack is detected, before further flight, replace the 
fitting with a fitting made of 7075-T73 or 7050-T7451 material in 
accordance with the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 747-53-2485, dated January 8, 2004. No 
further action is required by this AD for that fitting; however, 
paragraph (l) of this AD still applies.

Parts Installation

    (l) As of the date specified in paragraph (l)(1) or (l)(2) of 
this AD, as applicable, no person shall install on any airplane a 
stop support fitting of the MEDs made from either 7079-T651 or 7075-
T651 material.
    (1) For airplanes having line numbers 1 through 830 inclusive: 
As of January 25, 1999.
    (2) For airplanes having line numbers 831 through 1301 
inclusive: As of the effective date of this AD.

Alternative Methods of Compliance (AMOCs)

    (m)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19.
    (2) AMOCs, approved previously per AD 98-26-13, amendment 39-
10954, are approved as AMOCs with paragraph (f) or (g) of this AD, 
as applicable. However, any stop support fitting, 2L through 6L and 
2R through 6R, of MED 3 that was replaced is still required to be 
inspected as required in paragraph (h) of this AD.

    Issued in Renton, Washington, on November 26, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-26664 Filed 12-2-04; 8:45 am]
BILLING CODE 4910-13-P