[Federal Register Volume 71, Number 2 (Wednesday, January 4, 2006)]
[Proposed Rules]
[Pages 299-303]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E5-8244]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-360-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400, 777-200, and 777-
300 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to Boeing Model 747-400, 777-200, and 777-
300 series airplanes, that would have required an inspection of the 
flight deck humidifier to determine certain part numbers. That proposed 
AD also would have required, for certain airplanes, replacing the cell 
stack of the flight deck humidifier with a supplier-tested cell stack, 
or replacing the cell stack with a blanking plate and subsequently 
deactivating the flight deck humidifier, if necessary. For other 
airplanes, that proposed AD would have required replacing the cell 
stack with a supplier-tested cell stack, or replacing the cell stack 
with a blanking plate and subsequently deactivating the humidifier 
system, if necessary. The proposed AD also would have allowed blanking 
plates to be replaced with cell stacks. This new action revises the 
proposed rule by adding airplanes to the applicability, requiring an 
inspection of the flight deck humidifier to determine certain part 
numbers on certain airplanes, and requiring replacement of the cell 
stack on certain other airplanes. The actions specified by this new 
proposed AD are intended to prevent an increased pressure drop across 
the humidifier and consequent reduced airflow to the flight deck, which 
could result in the inability to clear any smoke that might appear in 
the flight deck. This action is intended to address the identified 
unsafe condition.

DATES: Comments must be received by January 30, 2006.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-360-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. 2000-NM-360-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 Airplanes, 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: Jeffrey S. Palmer, Aerospace Engineer, 
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,

[[Page 300]]

Washington 98055-4056; telephone (425) 917-6481; 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 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
     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.
     For each issue, state what specific change to the proposed 
AD is being requested.
     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 2000-NM-360-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. 2000-NM-360-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
Boeing Model 747-400, 777-200, and 777-300 series airplanes, equipped 
with a Hamilton Sundstrand flight deck humidifier, was published as a 
supplemental notice of proposed rulemaking (referred to hereafter as 
the first SNPRM) in the Federal Register on January 6, 2005 (70 FR 
1211).
    The first SNPRM would have required an inspection of the flight 
deck humidifier to determine certain part numbers. The first SNPRM also 
would have required, for certain airplanes, replacing the cell stack of 
the flight deck humidifier with a supplier-tested cell stack, or 
replacing the cell stack with an end plate and subsequent deactivation 
of the flight deck humidifier, if necessary. For other airplanes, the 
first SNPRM would have required replacing the cell stack with a 
supplier-tested cell stack, or replacing the cell stack with a blanking 
plate and subsequent deactivation of the humidifier system, if 
necessary. The first SNPRM also would have allowed end plates or 
blanking plates to be replaced with cell stacks.
    The first SNPRM was prompted by reports of sagging cell stack 
membranes of the flight deck humidifiers. That condition, if not 
corrected, could result in an increased pressure drop across the 
humidifier and consequent reduced airflow to the flight deck, which 
could result in the inability to clear any smoke that might appear in 
the flight deck.

Actions Since Issuance of First SNPRM

    Since the issuance of the first SNPRM, Boeing has issued Boeing 
Alert Service Bulletin 747-21A2414, Revision 2, dated July 7, 2005 
(Revision 1, dated October 26, 2000, was referenced as an applicable 
source of service information for doing the actions in that SNPRM); and 
Boeing Alert Service Bulletin 777-21A0048, Revision 2, dated July 14, 
2005 (Revision 1, dated September 7, 2000, was referenced as an 
applicable source of service information for doing the actions in the 
first SNPRM). Revision 2 of the alert service bulletins contains 
essentially the same procedures for the replacement of certain cell 
stacks of the flight deck humidifier. However, Revision 2 of the alert 
service bulletins adds airplanes to the effectivity. For those 
airplanes, Revision 2 of the alert service bulletin adds a procedure to 
inspect for a certain flight deck humidifier and inspect for a certain 
cell stack if necessary. Revision 2 of the alert service bulletins also 
specifies on which airplanes the replacement should be accomplished.
    We have made the following changes to the first SNPRM:
     We have revised the applicability of this second SNPRM to 
reference Revision 2 of the alert service bulletins.
     We have referenced Revision 2 of the alert service 
bulletins as the appropriate source of service information for 
accomplishing the cell stack replacements.
     We have also revised the format of this second SNPRM to 
clarify that a new or supplier-tested cell stack may be installed on 
flight deck humidifiers that have a blanking plate; paragraphs (a) and 
(d) of this second SNPRM (cited as paragraphs (b) and (e) of the first 
SNPRM) include the information on blanking plate replacement that was 
specified in paragraphs (b)(3) and (e)(3) of the first SNPRM. In 
addition, for the blanking plate replacement specified in paragraph (a) 
of this second SNPRM, we specify that the replacement be done in 
accordance with Hamilton Sundstrand Service Bulletin 821486-21-01, 
dated March 15, 2000, and that if the flight deck humidifier is 
activated after the replacement, the humidifier must be activated in 
accordance with Boeing Service Bulletin 747-21-2405, Revision 4, dated 
July 29, 1999.
     We have revised the format of this second SNPRM to require 
that certain airplanes do the inspections for part numbers and then 
replace the cell stack if necessary and that certain other airplanes 
replace the cell stack. Revision 2 of the alert service bulletins 
specifies on which airplanes (identified according to groups in the 
alert service bulletins) to do the inspection and then the replacement 
if necessary, and on which airplanes to do the replacement.
     We have revised the cost estimate of this second SNPRM.

Comments

    We have also given due consideration to the comments received in 
response to the first SNPRM.

Request To Revise Number of Affected Airplanes

    One commenter, the manufacturer, requests that the number of 
airplanes that could be fitted with the potentially defective cell 
stack be revised from 114 airplanes, as stated in the ``Request to 
Withdraw the Proposed AD'' section of the first SNPRM, to 176 
airplanes. The commenter states that 176 humidifiers have been 
delivered that could have the potentially defective cell stacks.
    We agree with the commenter that the total number of airplanes that 
could be fitted with the potentially defective cell stack is 176. We 
have revised the number in the Cost Impact section of this second 
SNPRM.

Request To Allow Additional Records Review

    The same commenter requests that we add an additional records 
review to allow operators to show compliance

[[Page 301]]

with the intent of the first SNPRM. The commenter states that if an 
airplane or retrofit kit was delivered after December 16, 1999, and the 
record review shows that the humidifier or cell stack was not replaced 
since, no inspection or replacement of the humidifier is needed. The 
commenter notes that December 16, 1999 is the delivery date of the 
first airplane that was delivered with an acceptable cell stack that 
was screened in production. The commenter contends that all humidifier 
deliveries would thereafter contain a cell stack that is not 
susceptible to the unsafe condition.
    We partially agree with the commenter. We acknowledge that 
airplanes delivered after December 16, 1999, would not require that the 
humidifier be inspected or replaced if there has not been any 
maintenance on the humidifier and the appropriate part markings could 
be determined. However, we have not revised the requirements for the 
records review specified in the first SNPRM since this review would 
include airplanes delivered with a known good cell stack. As specified 
in paragraphs (c) and (f) of this second SNPRM, a records review would 
be allowed in lieu of the inspection.

Request To Revise Nomenclature

    The same commenter requests that the term ``end plate'' in the 
first SNPRM be revised to ``blanking plate.'' The commenter states that 
an end plate is actually a part that exists in the cell stack assembly, 
while a blanking plate is a part that can be installed in lieu of the 
cell stack. The commenter recommends that the first SNPRM describe part 
number (P/N) 1001157-1 as a blanking plate.
    We agree with the commenter. Where the first SNPRM specifies an end 
plate, we have revised this second SNPRM to specify a blanking plate.

Clarification of P/Ns

    Boeing Alert Service Bulletin 747-21A2414, Revision 2, dated July 
7, 2005, specifies the cell stack P/N as 103111-2 in paragraph 3. of 
``Group 2-3: Part 3--Cell Stack Part Number Inspection'' of the 
Accomplishment Instructions of the service bulletin. The correct P/N is 
1003111-2.
    Boeing Alert Service Bulletin 777-21A0048, Revision 2, dated July 
14, 2005, specifies the cell stack P/N as 10311-1 in paragraph 2.C. of 
``Parts Necessary For Each Airplane'' and 2.D. of ``Parts Necessary to 
Change Spares'' of the service bulletin. The correct P/N is 1003111-1.

Explanation of Change Made to This AD

    We have revised paragraph (d)(1) of this second SNPRM to clarify 
the delegation authority for Authorized Representatives for the Boeing 
Commercial Airplanes Delegation Option Authorization.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

    We have revised this second SNPRM to clarify the appropriate 
procedure for notifying the principal inspector before using any 
approved AMOC on any airplane to which the AMOC applies.

Conclusion

    Since this change expands the scope of this second SNPRM, the FAA 
has determined that it is necessary to reopen the comment period to 
provide additional opportunity for public comment.

Cost Impact

    There are approximately 176 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 29 airplanes of U.S. registry 
would be affected by this second SNPRM. The cost per airplane would 
range between $390 and $6,248 per airplane, depending on the actions 
chosen by the operator. The fleet cost estimate would not exceed 
$181,192.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                       Cost per
            Model/series                      Action           Work hours  Hourly rate   Parts cost    airplane
----------------------------------------------------------------------------------------------------------------
747-400, 777-200, 777-300...........  Inspect flight deck               1          $65           $0          $65
                                       humidifier for part
                                       number and inspect
                                       flight deck
                                       humidifier cell stack
                                       for part number.
747-400.............................  Replace cell stack                3           65        5,100        5,295
                                       with new or supplier-
                                       tested cell stack.
747-400.............................  Replace cell stack                5           65            0          325
                                       with blanking plate
                                       and deactivate
                                       humidifier.
777-200, 777-300....................  Replace cell stack                3           65            0          195
                                       with blanking plate.
777-200, 777-300....................  Replace cell stack                3           65        6,053        6,248
                                       with new or supplier-
                                       tested cell stack.
777-200, 777-300....................  Replace blanking plate            1           65        6,053        6,118
                                       with supplier-tested
                                       cell stack.
----------------------------------------------------------------------------------------------------------------

    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.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. 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.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA 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 
rulemaking action.

[[Page 302]]

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 2000-NM-360-AD.
    Applicability: Model 747-400, 777-200, and 777-300 series 
airplanes, certificated in any category; as identified in Boeing 
Alert Service Bulletin 747-21A2414, Revision 2, dated July 7, 2005; 
and Boeing Alert Service Bulletin 777-21A0048, Revision 2, dated 
July 14, 2005.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent an increased pressure drop across the humidifier and 
consequent reduced airflow to the flight deck, which could result in 
the inability to clear any smoke that might appear in the flight 
deck, accomplish the following:

Cell Stack Replacement: Model 747-400 Series Airplanes

    (a) For Model 747-400 series airplanes identified as Group 1 in 
Boeing Alert Service Bulletin 747-21A2414, Revision 2, dated July 7, 
2005: Within 90 days after the effective date of this AD, do the 
replacement specified in paragraph (a)(1) or (a)(2) of this AD. For 
flight deck humidifiers with a blanking plate: If the blanking plate 
is removed and a new or supplier-tested cell stack is installed, the 
replacement must be done in accordance with the Accomplishment 
Instructions of Hamilton Sundstrand Service Bulletins 821486-21-01, 
dated March 15, 2000; and after the replacement, the flight deck 
humidifier may be activated in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 747-21-2405, Revision 4, 
dated July 29, 1999.
    (1) Replace the cell stack of the flight deck humidifier with a 
supplier-tested cell stack, in accordance with Part 1 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
21A2414, Revision 2, dated July 7, 2005.
    (2) Replace the cell stack of the flight deck humidifier with a 
blanking plate and, before further flight, deactivate the flight 
deck humidifier, in accordance with Part 2 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-21A2414, Revision 
2, dated July 7, 2005.

    Note 1: Boeing Alert Service Bulletin 747-21A2414, Revision 2, 
dated July 7, 2005, refers to Boeing Service Bulletin 747-21-2405, 
Revision 4, dated July 29, 1999, as an additional source of service 
information for deactivating the humidifier.



    Note 2: Boeing Alert Service Bulletin 747-21A2414, Revision 2, 
dated July 7, 2005, refers to Hamilton Sundstrand Service Bulletins 
821486-21-01, dated March 15, 2000, as an additional source of 
service information for the cell stack replacements.

    (b) Replacement of the cell stack before the effective date of 
this AD in accordance with Boeing Alert Service Bulletin 747-
21A2414, dated April 13, 2000; or Revision 1, dated October 26, 
2000; is acceptable for compliance with the applicable requirements 
of paragraphs (a)(1) and (a)(2) of this AD.

Inspections/Records Review: Model 747-400 Series Airplanes

    (c) For Model 747-400 series airplanes identified as Groups 2 
and 3 in Boeing Alert Service Bulletin 747-21A2414, Revision 2, 
dated July 7, 2005: Within 90 days after the effective date of this 
AD, inspect the flight deck humidifier to determine whether part 
number (P/N) 821486-1 is installed, in accordance with Part 3 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
21A2414, Revision 2, dated July 7, 2005. Instead of inspecting the 
flight deck humidifier, a review of airplane maintenance records is 
acceptable if the P/N of the flight deck humidifier can be 
positively determined from that review.
    (1) If a P/N other than P/N 821486-1 is installed, no further 
action is required by this paragraph.
    (2) If P/N 821486-1 is installed, inspect the flight deck 
humidifier cell stack to determine whether P/N 821482-1 is installed 
and ``DEV 13433'' is not marked next to the cell stack part number, 
in accordance with Part 3 of the Accomplishment Instructions of the 
alert service bulletin. Instead of inspecting the flight deck 
humidifier cell stack, a review of airplane maintenance records is 
acceptable if the P/N, including whether ``DEV 13433'' is marked 
next to the P/N, of the flight deck humidifier cell stack can be 
positively determined from that review.
    (i) If the cell stack has P/N 821482-2 or 1003111-2, or if ``DEV 
13433'' is marked next to P/N 821482-1, no further action is 
required by this paragraph.
    (ii) If the cell stack has P/N 821482-1 and does not have ``DEV 
13433'' marked next to the cell stack part number: Before further 
flight, do the replacement specified in paragraph (a) of this AD.

Cell Stack Replacement: Model 777-200 and -300 Series Airplanes

    (d) For Model 777-200 and 777-300 series airplanes identified as 
Groups 1 through 5 in Boeing Alert Service Bulletin 777-21A0048, 
Revision 2, dated July 14, 2005: Within 90 days after the effective 
date of this AD, do the replacement specified in paragraph (d)(1) or 
(d)(2) of this AD. For flight deck humidifiers with a blanking 
plate: If a blanking plate is removed and a new or supplier-tested 
cell stack installed, the cell stack installation must be done in 
accordance with Part 3 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 777-21A0048, Revision 2, dated July 14, 2005; 
and after the installation, the humidifier system may be activated 
in accordance with Accomplishment Instructions of Boeing Service 
Bulletin 777-21-0035, Revision 1, dated October 19, 2000.
    (1) Replace the cell stack with a blanking plate, in accordance 
with Part 1 of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 777-21A0048, Revision 2, dated July 14, 2005; and, 
before further flight, deactivate the humidifier system in 
accordance with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA, or in accordance with data meeting 
the certification basis of the airplane approved by an Authorized 
Representative for the Boeing Commercial Airplanes Delegation Option 
Authorization who has been authorized by the Manager, Seattle ACO, 
to make those findings. For a deactivation method to be approved, 
the deactivation must meet the certification basis of the airplane, 
and the approval must specifically reference this AD.
    (2) Replace the cell stack with a supplier-tested cell stack, in 
accordance with Part 2 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 777-21A0048, Revision 2, dated July 14, 2005.

    Note 3: Boeing Alert Service Bulletin 777-21A0048, Revision 2, 
dated July 14, 2005, refers to Hamilton Sundstrand Service Bulletin 
816086-21-01, dated March 15, 2000, as an additional source of 
service information for the cell stack replacement.


    (e) Replacement of the cell stack before the effective date of 
this AD in accordance with Boeing Service Bulletin 777-21A0048, 
Revision 1, dated September 7, 2000, is

[[Page 303]]

acceptable for compliance with the applicable requirements of 
paragraphs (d)(1) and (d)(2) of this AD.

Inspections/Records Review: Model 777-200 and -300 Series Airplanes

    (f) For Model 777-200 and 777-300 series airplanes identified as 
Groups 6 and 7 in Boeing Alert Service Bulletin 777-21A0048, 
Revision 2, dated July 14, 2005: Within 90 days after the effective 
date of this AD, inspect the flight deck humidifier to determine if 
it is P/N 816086-1, in accordance with Part 4 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 777-21A0048, Revision 
2, dated July 14, 2005. Instead of inspecting the flight deck 
humidifier, a review of airplane maintenance records is acceptable 
if the part number (P/N) of the flight deck humidifier can be 
positively determined from that review.
    (1) If a P/N other than P/N 816086-1 is installed, no further 
action is required by this paragraph.
    (2) If P/N 816086-1 is installed, inspect the flight deck 
humidifier cell stack to determine whether P/N 822976-2 is installed 
and ``DEV 13433'' is not marked next to the cell stack part number, 
in accordance with Part 4 of the Accomplishment Instruction of the 
alert service bulletin. Instead of inspecting the flight deck 
humidifier cell stack, a review of airplane maintenance records is 
acceptable if the P/N, including whether ``DEV 13433'' is marked 
next to the P/N, of the flight deck humidifier cell stack can be 
positively determined from that review.
    (i) If the cell stack has P/N 822976-3 or 1003111-1, or if ``DEV 
13433'' is marked next to P/N 822976-2, no further action is 
required by this paragraph.
    (ii) If the cell stack has P/N 822976-2 and does not have ``DEV 
13433'' marked next to the cell stack part number, before further 
flight, do the replacement specified in paragraph (d) of this AD.

Parts Installation

    (g) On Model 747-400 series airplanes: As of the effective date 
of this AD, no person may install a flight deck humidifier cell 
stack having P/N 821482-1, unless ``DEV 13433'' is also marked next 
to the cell stack part number.
    (h) On Model 777-200 and 777-300 series airplanes: As of the 
effective date of this AD, no person may install a flight deck 
humidifier cell stack having P/N 822976-2, unless ``DEV 13433'' is 
also marked next to the cell stack part number.

Alternative Methods of Compliance

    (1) In accordance with 14 CFR 39.19, the Manager, Seattle ACO, 
is authorized to approve alternative methods of compliance for this 
AD.
    (2) Before using any AMOC approved in accordance with 14 CFR 
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

    Issued in Renton, Washington, on December 27, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.

[FR Doc. E5-8244 Filed 1-3-06; 8:45 am]
BILLING CODE 4910-13-P