[Federal Register: January 4, 2006 (Volume 71, Number 2)]
[Proposed Rules]
[Page 299-303]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04ja06-28]
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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:
9-anm-nprmcomment@faa.gov. 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