[Federal Register Volume 69, Number 96 (Tuesday, May 18, 2004)]
[Rules and Regulations]
[Pages 28051-28058]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-10907]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-40-AD; Amendment 39-13635; AD 2004-10-05]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400, 747-400D, 747-
400F, 757-200, 757-200PF, 757-200CB, 767-200, 767-300, and 767-300F 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing transport category airplane models, as 
listed above. This amendment requires a modification of the air data 
computer (ADC) system, which involves installing certain new circuit 
breakers, relays, and related components, and making various wiring 
changes in and between the flight deck and main equipment center. For 
certain airplanes, this amendment also requires accomplishment of 
various other actions prior to or concurrently with the modification of 
the ADC system. For certain airplanes, this amendment also contains an 
option that will extend the compliance time to accomplish the 
modification of the ADC system. This action is necessary to ensure that 
the flightcrew is able to silence an erroneous overspeed or stall aural 
warning. A persistent erroneous warning could confuse and distract the 
flightcrew and lead to an increase in the flightcrew's workload. Such a 
situation could lead the flightcrew to act on hazardously misleading 
information, which could result in loss of control of the airplane. 
This action is intended to address the identified unsafe condition.

DATES: Effective June 22, 2004.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 22, 2004.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call (202) 741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

FOR FURTHER INFORMATION CONTACT: Elizabeth Zurcher, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6495; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing transport category 
airplane models was published in the Federal Register on July 17, 2003 
(68 FR 42317). That action proposed to require a modification of the 
air data computer (ADC) system, which involves installing certain new 
circuit breakers, relays, and related components, and making various 
wiring changes in and between the flight deck and main equipment 
center. For certain airplanes, that action also proposed to require 
accomplishment of various other actions prior to or concurrently with 
the modification of the ADC system.

Actions Since Issuance of the Proposed Rule

    Since issuance of the proposed rule, we have reviewed and approved 
the following Boeing service bulletins:
     757-34A0222, Revision 1, dated July 17, 2003 (for Model 
757-200, -200PF, and -200CB series airplanes), which describes 
procedures for installing a circuit breaker and replacing an existing 
lightplate assembly with a new, improved lightplate assembly in the 
flight compartment; installing two relays and removing a certain relay 
in the main equipment center; making various wiring changes in the 
flight compartment and main equipment center; and performing tests of 
the flight data acquisition unit, flight data recorder system, and 
stall and

[[Page 28052]]

overspeed warnings. These changes are intended to allow the flightcrew 
to silence an erroneous aural overspeed or stall warning by switching 
away from a failed ADC that is generating the warning. This service 
bulletin specifies that Boeing Service Bulletin 757-31-0059 must be 
accomplished either previously or concurrently. We have revised this 
final rule to include reference to Revision 1 of the service bulletin 
as the appropriate source of service information for the required 
modification (for Model 757-200, -200PF, and -200CB series airplanes).
     767-34A0332, Revision 1, dated April 24, 2003 (for Model 
767-200, -300, and -300F series airplanes), which describes procedures 
for modifying the air data switching system and doing a system 
functional test. These changes are intended to allow the flightcrew to 
silence an erroneous aural overspeed or stall warning by switching away 
from a failed ADC that is generating the warning. This service bulletin 
specifies that Boeing Service Bulletins 767-31-0091, 767-31-0098, 767-
31-0099, 767-31-0100, or 767-31-0101, as applicable, must be 
accomplished either previously or concurrently. We have revised this 
final rule to include reference to Revision 1 of the service bulletin 
as the appropriate source of service information for the required 
modification (for Model 767-200, -300, and -300F series airplanes). 
Revision 1 of the service bulletin contains an increase in the work 
hour estimate for the change and test from 55 to 124 work hours.
    We also have reviewed and approved the following Boeing special 
attention service bulletins:
     747-31-2313, Revision 1, dated September 26, 2002 (for 
Model 747-400, -400D, and -400F series airplanes), which describes 
procedures for changing the termination of two wires on the MAWEA card 
file and for performing an operational test.
     757-31-0068, Revision 1, dated August 29, 2002 (for Model 
757-200, -200CB, and -200PF series airplanes), which describes 
procedures for changing two wires in wire bundle W1451 at the P51 
warning electronics card file panel and for performing an operational 
test.
     767-31-0149, Revision 1, dated November 7, 2002 (for Model 
767-200, -300, and -300F series airplanes), which describes procedures 
for changing the wire termination on the left and right siren owl 
amplifier modules in the P51 warning electronics unit and for 
performing an operational test.
    We have revised the final rule to reference these Boeing special 
attention service bulletins as the appropriate source of service 
information for the optional interim measure that has been added to the 
final rule.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Extend Compliance Time

    Several commenters request that the compliance time for 
modification that is specified in the proposed AD be extended from 24 
months to compliance times that range between 42 to 72 months. The 
commenters cite significant out-of-service costs and logistical impact 
associated with a 24-month compliance time requirement. Some commenters 
suggest that there are FAA-approved service instructions (i.e., Boeing 
Special Attention Service Bulletin 747-31-2313, Revision 1, dated 
September 26, 2002; Boeing Special Attention Service Bulletin 757-31-
0068, Revision 1, dated August 29, 2002; and Boeing Special Attention 
Service Bulletin 767-31-0149, Revision 1, dated November 7, 2002) that 
could be incorporated to allow flightcrews to silence aural overspeed 
warnings as an interim action. They propose that the FAA add an option 
to accomplish the interim action within 12 or 18 months and then 
accomplish the modification within 60 or 72 months after the effective 
date of the AD.
    The FAA agrees with the commenters that operators could experience 
significant out-of-service cost and logistical impacts associated with 
a 24-month compliance time. We also agree that an optional interim 
action be added to allow flightcrews to silence aural overspeed 
warnings as specified in the Boeing special attention service bulletins 
described earlier. We find that, if the optional interim action is 
accomplished within 18 months, the required modification can be 
accomplished within 72 months after the effective date of this final 
rule and will maintain an acceptable level of safety without an 
additional burden to the operators. Therefore, we have added an option 
so that operators may accomplish the required modification in one of 
two ways:
    1. Accomplish the required modification as originally proposed 
within 24 months after the effective date of the final rule; or
    2. Accomplish the interim action specified in the applicable Boeing 
special attention service bulletin within 18 months after the effective 
date of the final rule and accomplish the required modification 
specified in the applicable Boeing service bulletin within 72 months 
after the effective date of the final rule. The following table lists 
the applicable service bulletins for the interim measure and required 
modification.

                   Table--Applicable Service Bulletins
------------------------------------------------------------------------
                     Boeing Service Bulletin                       Model
------------------------------------------------------------------------
Special Attention Service Bulletin 747-31-2313, Revision 1,          747
 dated September 26, 2002.......................................
Alert Service Bulletin 747-34A2460, Revision 2, dated June 14,       747
 2001...........................................................
Special Attention Service Bulletin 757-31-0068, Revision 1,          757
 dated August 29, 2002..........................................
Service Bulletin 757-34A0222, Revision 1, dated July 17, 2003...     757
Special Attention Service Bulletin 767-31-0149, Revision 1,          767
 dated November 7, 2002.........................................
Service Bulletin 767-34A0332, Revision 1, dated April 24, 2003..     767
------------------------------------------------------------------------

    Accordingly, we have revised the final rule by adding the new 
compliance times to paragraph (a) of the final rule, adding the 
optional interim action as new paragraph (b) of the final rule, and 
moving the requirements for the modification (specified in paragraph 
(a) of the proposed AD) to paragraph (c) of the final rule.

Request for an Alternative Method of Compliance (AMOC) to the Proposed 
AD

    One commenter requests that an AMOC be considered. The commenter 
states that its safety management has not identified the inability to 
silence an erroneous warning as a potential safety issue and questions 
if the severity of the failure and probability of an event justify the 
compliance time of the proposed AD. The commenter contends that the 
compliance time of 24 months will be costly and cause logistical and 
supply problems. The commenter suggests that AMOCs such as a flightcrew 
drill would be a way to maintain an acceptable level of safety without 
requiring the AD.
    We do not agree that the flightcrew drill suggested by the 
commenter would be an acceptable AMOC primarily because it requires 
tripping circuit breakers, which is against standard practice and could 
result in the loss of other necessary airplane systems. However, under 
the provisions of paragraph (h) of the final rule, we may

[[Page 28053]]

consider requests for approval of an AMOC if sufficient data are 
submitted to substantiate that such an AMOC would provide an acceptable 
level of safety. No change is necessary to the final rule in this 
regard.

Request To Withdraw the Proposed AD

    One commenter states that, if there is a low frequency of erroneous 
audio warnings and an acceptable flightcrew drill is available to 
cancel the warnings, then it is questionable whether the proposed AD is 
required to maintain an acceptable level of compliance.
    We infer from the commenter's statement that the commenter requests 
to withdraw the proposed AD. We do not agree with the request to 
withdraw the proposed AD. We find that sufficient data exist to 
demonstrate that an erroneous aural warning that cannot be silenced may 
cause the flightcrew to act based on misleading information. We 
consider this condition unsafe since it could result in incidents in 
which flightcrew actions based on hazardously misleading information 
result in loss of control of the airplane. We find that modification of 
the ADC system, as required by this AD, will adequately address the 
unsafe condition. No change is necessary to the final rule in this 
regard.

Request To Remove ``Parts Installation'' Paragraph

    One commenter requests to remove the ``Parts Installation'' 
paragraph (paragraph (c) of the proposed AD). The commenter contends 
that paragraph (c) of the proposed AD is redundant to AD 96-07-09, 
amendment 39-9588 (61 FR 14608, April 3, 1996), which advises 
flightcrews to monitor the engine indication and crew alerting system 
(EICAS) for ``status'' level messages pertaining to impending engine 
fuel filter bypass and requires installation of upgraded EICAS 
computers.
    We do not agree that paragraph (e) of the final rule (specified in 
paragraph (c) of the proposed AD) should be removed. Paragraph (c) of 
the proposed AD is not redundant to AD 96-07-09. AD 96-07-09 requires 
the installation of certain computers, while the intent of paragraph 
(e) of the final rule is to prevent an identified unsafe condition from 
being introduced into the fleet. However, we do find that the parts 
listed in Boeing Alert Service Bulletin 747-34A2460, Revision 2, dated 
June 14, 2001, may be used after the effective date of the final rule 
with an acceptable level of safety until the required modification. 
Therefore, we have removed Boeing Alert Service Bulletin 747-34A2460, 
Revision 2, dated June 14, 2001, from paragraph (e) of the final rule.

Request To Revise Compliance Time in ``Parts Installation'' Paragraph

    One commenter requests that the compliance time of the ``Parts 
Installation'' paragraph (paragraph (c) of the proposed AD) be revised 
to ``as of 24 months after the effective date of the AD.'' The 
commenter notes that the compliance time specified in paragraph (c) of 
the proposed AD implies that no ``Existing Part Number'' may be 
installed upon the effective date of the AD. The commenter states that 
this indicates existing parts are no longer useable immediately upon 
the effective date of the AD, regardless of the airplane modification 
status. The commenter believes the paragraph should state that existing 
parts could no longer be used following incorporation of the various 
service bulletins, not to exceed 24 months after the effective date of 
the AD.
    We do not agree to revise the compliance time of paragraph (e) of 
the final rule (specified in paragraph (c) of the proposed AD). In 
general, once we have determined that an unsafe condition exists, our 
normal policy specifies not to allow that condition to be introduced 
into the fleet. In developing the technical information on which every 
AD is based, we consider the availability of spare parts that the AD 
will require to be installed. When we have determined that those 
(spare) parts are immediately available to operators, our policy 
prohibits installation of the unsafe parts after the effective date of 
the AD. However, as stated previously, we have removed Boeing Alert 
Service Bulletin 747-34A2460, Revision 2, dated June 14, 2001, from 
paragraph (e) of the final rule as its parts may be used after the 
effective date of the final rule with an acceptable level of safety 
until the modification required by this AD is accomplished. No 
additional change is made in this regard.

Request To Use Latest Versions of Certain Service Bulletins

    Several commenters request that the proposed AD be revised to 
reference the latest versions of certain service bulletins, i.e., 
Boeing Service Bulletin 767-34A0332, Revision 1, dated April 24, 2003; 
and Boeing Service Bulletin 757-34A0222, Revision 1, dated July 17, 
2003. The commenters also request that earlier versions of these 
service bulletins be clearly stated as acceptable for accomplishment of 
the applicable actions.
    We agree with the commenters that the latest revisions of the two 
service bulletins stated above should be referenced in this AD. Since 
the proposed AD was issued, Boeing has revised these two service 
bulletins and the FAA has approved both service bulletins. The new 
revisions correct minor errors relating to the position of the 
available ground studs and length of wiring only. Therefore, we also 
agree that previous incorporation of the original version of the 
service bulletins is acceptable for accomplishment of the applicable 
actions. We have revised the final rule to reference Boeing Service 
Bulletins 757-34A0222, Revision 1, dated July 17, 2003; and 767-
34A0332, Revision 1, dated April 24, 2003; as appropriate sources of 
service information and have revised the applicability of the final 
rule to reference these service bulletins. There is no change in the 
airplane variable numbers in the effectivity of the service bulletins. 
However, operators should note that the estimated number of work hours 
for Boeing Service Bulletin 767-34A0332, Revision 1, dated April 24, 
2003, has been revised from 55 to 124 work hours to more accurately 
reflect the time required for the change/test. The manufacturer based 
its estimate of the work hours in the original service bulletin on a 
simple airplane configuration. Because most operators have more complex 
airplane configurations, Revision 1 of the service bulletin shows a 
revised estimate of 124 work hours for the change/test. Accordingly, we 
have revised the ``Cost Impact'' paragraph of the final rule.

Request To Refer to Later Revision of a Certain Service Bulletin

    One commenter requests that the proposed AD refer to a later 
revision of a certain service bulletin. The commenter states that the 
proposed AD refers to Boeing Alert Service Bulletin 767-34A0332, dated 
January 10, 2002, and that they have received Boeing Service Bulletin 
767-34A0332, Revision 1, dated April 24, 2003. The commenter contends 
that Revision 1 of the service bulletin has many deviations from their 
actual airplane configuration. The commenter states that they have 
asked Boeing to release a revised service bulletin and they were 
informed Boeing would issue Revision 2 of the service bulletin in late 
2003. The commenter recommends that we refer to Revision 2 of the 
service bulletin in order for operators to accomplish the proposed AD 
smoothly.
    We do not agree to refer to Revision 2 of Boeing Service Bulletin 
767-34A0332. Revision 2 of the service

[[Page 28054]]

bulletin has not been issued and Boeing does not expect to issue 
Revision 2 until late 2004. We cannot refer to a document that we have 
not reviewed and approved. We also cannot use the phrase, ``or later 
FAA-approved revisions,'' in an AD when referring to the service 
document because doing so violates Office of the Federal Register (OFR) 
regulations for approval of materials ``incorporated by reference'' in 
rules. In general terms, we are required by these OFR regulations to 
publish either the service document contents as part of the actual AD 
language; or to submit the service document to the OFR for approval as 
``referenced'' material, in which case we may only refer to such 
material in the text of an AD. The AD may refer to the service document 
only if the OFR approved it for ``incorporation by reference.'' To 
allow operators to use later revisions of the referenced document 
(issued after publication of the AD), either we must revise the AD to 
reference specific later revisions, or operators must request approval 
to use later revisions as an alternative method of compliance with this 
AD under the provisions of paragraph (h) of this AD. No change is made 
to the final rule in this regard.

Request To Clarify Intent of Prior/Concurrent Actions

    One commenter requests that the intent of the proposed AD, with 
respect to prior/concurrent service bulletin actions, be clarified by 
revising paragraph (b) of the proposed AD and adding a new paragraph 
after paragraph (b)(2) of the proposed AD. The commenter states the 
software versions specified in the service bulletins listed in Tables 2 
and 3 of the proposed AD are outdated and have been revised many times 
since the service bulletins were issued. The commenter points out the 
proposed AD, as written, would require a reversion to older software 
and hardware. The commenter recommends revising paragraph (b) of the 
proposed AD to state ''* * * accomplish paragraph (b)(1), (b)(2), or 
(b)(3) of this AD,'' and adding new paragraph (b)(3) as follows: ``No 
additional work is necessary on airplanes that have been previously 
accomplished per the actions specified in Tables 2 and 3. Subsequent 
software and hardware changes made after implementation of service 
bulletins specified in Tables 2 and 3 are considered acceptable when 
accomplished per a later FAA-approved document.''
    We agree with the commenter that previous accomplishment of 
``prior/concurrent'' service bulletins is acceptable for compliance. 
However, we do not agree with the commenter that the ``proposed AD, as 
written, would require a reversion to older software and hardware.'' As 
stated in new paragraph (d) of the final rule (specified in paragraph 
(b) of the proposed AD), the actions in (d)(1) or (d)(2) of the final 
rule are to be accomplished ``prior to or concurrently'' with 
accomplishment of paragraph (c) of the final rule (specified in 
paragraph (a) of the proposed rule). Therefore, no more work is 
necessary on airplanes that previously accomplished the actions 
specified in Tables 2 and 3 of the final rule. We also do not agree 
with the commenter that software and hardware changes made per a later 
FAA-approved document be added as acceptable for compliance. When 
referencing a specific service bulletin in an AD, using the phrase, 
``or later FAA-approved document,'' violates Office of the Federal 
Register regulations for approving materials that are incorporated by 
reference. However, affected operators may request approval to use a 
later FAA-approved document as an alternative method of compliance, 
under the provisions of paragraph (h) of the final rule. No change to 
the final rule is necessary in this regard.

Request To Confirm Use of AMOC for Operator's Equivalent Procedures 
(OEPs)

    One commenter requests confirmation that the use of OEPs will 
require AMOC approval and requests a name and address for AMOC 
submittal.
    We do confirm that the use of OEPs requires AMOC approval as 
specified in paragraph (f) of the final rule (specified in paragraph 
(d) of the proposed AD): ``An operator's ``equivalent procedure'' 
cannot be used unless the operator receives FAA approval for that 
procedure according to paragraph (h) of this AD.'' Requests for AMOCs 
should be sent to the Manager of the Seattle Aircraft Certification 
Office at the address listed in the ``For Further Information Contact'' 
paragraph in the preamble of this final rule. No change to the final 
rule is necessary in this regard.

Requests To Remove Certain Service Bulletins From the Proposed AD

    One commenter requests that Boeing Service Bulletin 767-31-0101 be 
removed from Table 3 of the proposed AD. The commenter notes that Table 
1 of the proposed AD specifies that Model 767-200 series airplanes 
listed in Boeing Service Bulletin 767-34A0332 are part of the 
applicability of the proposed AD. However, paragraph (b)(2) of the 
proposed AD specifies that all services bulletins listed in Table 3 
must be accomplished prior to or concurrently with the actions required 
by paragraph (a) of the proposed AD. The commenter states that the 
wording in paragraph (b)(2) of the proposed AD will mandate 
accomplishment of Boeing Service Bulletin 767-31-0101 for Model 767-200 
series airplanes that are not part of the applicability of the proposed 
AD as listed in Table 1. The commenter adds that its Model 767-200 
series airplanes, which are listed in Service Bulletin 767-31-0101, are 
not part of the applicability of the proposed AD. The commenter 
contends that the primary intent of the proposed AD is to accomplish 
the service bulletins listed in Table 1 of the proposed AD and to 
accomplish concurrent requirements for airplanes that are part of the 
Table 1 applicability.
    We do not agree with the commenter's request to remove Boeing 
Service Bulletin 767-31-0101 from Table 3 of the final rule. Although 
the commenter does not have airplanes listed in Service Bulletin 767-
31-0101 that are part of the applicability of the final rule, there are 
Model 767-200 series airplanes for other operators affected by this 
final rule. We also do not agree that the wording in paragraph (b)(2) 
of the proposed AD (specified in paragraph (d)(2) of the final rule) 
will mandate accomplishment of Boeing Service Bulletin 767-31-0101 for 
Model 767-200 series airplanes that are not part of the applicability 
of this final rule. The intent of the AD is to accomplish the service 
bulletins listed in Table 1 of the AD and to accomplish concurrent 
requirements only on airplanes that are part of the Table 1 
applicability. Paragraph (d)(2) of the final rule (specified in 
paragraph (b)(2) of the proposed rule) does not mandate accomplishment 
of the service bulletins listed in Tables 2 and 3 of the final rule for 
all the airplanes listed in the effectivity of the listed service 
bulletins, because the applicability of the final rule takes precedence 
over the effectivity listed in any service bulletin. Because the 
applicability statement in all AD actions lists all airplanes affected 
by that AD, all of the requirements stated in an AD are applicable only 
to the airplanes listed in the applicability, unless otherwise 
specified in the AD. However, we have revised the wording in paragraph 
(d)(2) of the final rule (specified in paragraph (b)(2) of the proposed 
rule) for clarity.
    One commenter requests that all references to Boeing Service 
Bulletin 757-31-0059 be removed from the proposed AD. We infer from the 
commenter that it contends the references to Service Bulletin are 
redundant to AD 96-07-09, which was

[[Page 28055]]

described previously under the heading ``Request to Remove `Parts 
Installation' Paragraph.''
    We do not agree with the request to remove all references to Boeing 
Service Bulletin 757-31-0059 from the final rule. While Service 
Bulletin 757-31-0059 is related to AD 96-07-09, that AD does not 
require accomplishment of Service Bulletin 757-31-0059. Therefore, 
Boeing Service Bulletin 757-31-0059 is a required ``prior to/
concurrent'' service bulletin for this final rule. No change is made to 
the final rule in this regard.

Request To Clarify Modification Steps in Paragraph (a)(3) of the 
Proposed AD

    One commenter requests that paragraph (a)(3) of the proposed AD be 
clarified to indicate which steps are required for the modification. 
The commenter believes the intent of paragraph (a)(3) of the proposed 
AD might be unclear because only certain steps of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 767-34A0332 are listed. 
The commenter suggests revising paragraph (a)(3) of the proposed AD to 
read: ``For Model 767-200, -300, and -300F series airplanes: Modify the 
air data switching system and do a systems functional test according to 
Boeing Service Bulletin 767-34A0332, Revision 1, dated April 24, 
2003.''
    We agree that paragraph (c)(3) of the final rule (specified in 
paragraph (a)(3) of the proposed AD) should be clarified to indicate 
which steps are required for the modification. Although we used wording 
referring only to the major steps of the service bulletin in the 
proposed AD, it was our intent to require all the steps of the service 
bulletin. Accordingly, we have revised paragraph (c)(3) of the final 
rule (specified in paragraph (a)(3) of the proposed AD) to state ``For 
Model 767-200, -300, and -300F series airplanes: Modify the air data 
switching system and do a system functional test, according to Boeing 
Service Bulletin 767-34A0332, Revision 1, dated April 24, 2003.''

Request To Revise ``Cost Impact'' Paragraph

    Two commenters contend that it would take 250 work hours per 
airplane to accomplish the proposed AD due to the access time required 
and the time to accomplish the wiring modifications (the proposed AD 
estimates 175 work hours for 747 series airplanes, 112 work hours for 
the 757 series airplanes, and 105 work hours for the 767 series 
airplanes). One commenter also notes that it has extensive ``power-
off'' requirements for its 757 and 767 series airplanes. The other 
commenter states that for all 747, 757, and 767 series airplanes, the 
proposed AD also does not include costs for disturbed system checks, 
which it estimates at a minimum of 96 additional work hours.
    We infer from the commenters that they request the ``Cost Impact'' 
paragraph of the proposed AD be revised. We do not agree. As stated 
previously under the heading ``Request to Use Latest Versions of 
Certain Service Bulletins,'' we have revised the ``Cost Impact'' 
paragraph of the final rule for Boeing Service Bulletin 767-34A0332, 
Revision 1, dated April 24, 2003, by revising the work hours from 55 to 
124, to reflect more accurately the time required for the change/test. 
Our estimates 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. Disturbed system checks 
are part of close up and ensure that the airplane is in an airworthy 
condition, as required by the Federal Aviation Regulations and are not 
included in the cost estimate for the final rule. No additional changes 
are necessary to the final rule in this regard.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 1,872 airplanes of the affected designs in 
the worldwide fleet. The FAA estimates that 36 Model 747-400, -400D, 
and -400F series airplanes; 639 Model 757-200, -200CB, and -200PF 
series airplanes; and 244 Model 767-200, -300, and -300F series 
airplanes; of U.S. registry will be affected by this AD. Estimates of 
the costs to accomplish the required actions are provided in the 
following table:

                               Table--Cost Estimate for Required Service Bulletins
----------------------------------------------------------------------------------------------------------------
                                             Work hours     Hourly                                     Cost per
         Boeing Service Bulletin--              per       labor rate    Parts cost per airplane--     airplane--
                                             airplane--   (dollars)                                   (dollars)
----------------------------------------------------------------------------------------------------------------
747-31-2163...............................            2           65  None.........................          130
747-31-2178...............................            5           65  None.........................          325
747-31-2179...............................            2           65  None.........................          130
747-31-2180...............................            2           65  None.........................          130
747-31-2217...............................            2           65  None.........................          130
747-34A2460...............................          158           65  $1,448-                            11,718-
                                                                      $1,735.......................       12,005
747-45-2005...............................            2           65  None.........................          130
747-45-2010...............................            2           65  None.........................          130
757-31-0059...............................            5           65  None.........................          325
757-34A0222...............................          107           65  $12,571-                           19,526-
                                                                      $12,953......................       19,908
767-31-0091...............................            7           65  None.........................          455
767-31-0098...............................            5           65  None.........................          325
767-31-0099...............................           24           65  None.........................        1,560
767-31-0100...............................            8           65  None.........................          520
767-31-0101...............................            6           65  None.........................          390
767-34A0332...............................          124           65  $9,988-                            18,048-
                                                                      $11,167......................       19,227
----------------------------------------------------------------------------------------------------------------


[[Page 28056]]

    We estimate that the total cost to accomplish all actions that are 
required for all airplanes affected by this AD may be as much as 
$18,878,215.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.
    Estimates of the costs to accomplish the optional interim actions 
are provided in the following table:

                               Table--Cost Estimate for Optional Service Bulletins
----------------------------------------------------------------------------------------------------------------
                                                            Hourly
                                             Work hours  labor rate--                                  Cost per
         Boeing Service bulletin--              per        (dollars)    Parts cost per airplane--     airplane--
                                             airplane--                                               (dollars)
----------------------------------------------------------------------------------------------------------------
747-31-2313...............................            1           65  None.........................           65
757-31-0068...............................            2           65  None.........................          130
767-31-0149...............................            1           65  None.........................           65
----------------------------------------------------------------------------------------------------------------

Regulatory Impact

    The regulations adopted herein will not have a substantial direct 
effect on the States, on the relationship between the national 
Government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2004-10-05 Boeing: Amendment 39-13635. Docket 2003-NM-40-AD.

    Applicability: Airplanes as listed in Table 1 of this AD, 
certificated in any category. Table 1 of this AD follows:

                         Table 1--Applicability
------------------------------------------------------------------------
                                           As Listed in Boeing Service
            Airplane Model--                        Bulletin--
------------------------------------------------------------------------
747-400, 747-400D, 747-400F series       Boeing Alert Service Bulletin
 airplanes.                               747-34A2460,
                                         Revision 2, dated June 14,
                                          2001.
757-200, 757-200PF, 757-200CB series     Boeing Service Bulletin 757-
 airplanes.                               34A0222,
                                         Revision 1, dated July 17,
                                          2003.
767-200, 767-300, and 767-300F series    Boeing Service Bulletin 767-
 airplanes.                               34A0332,
                                         Revision 1, dated April 24,
                                          2003.
------------------------------------------------------------------------

    Compliance: Required as indicated, unless accomplished 
previously.
    To ensure that the flightcrew is able to silence an erroneous 
overspeed or stall aural warning, accomplish the following:

Compliance Times

    (a) Except as provided by paragraph (a)(3) of this AD, do the 
actions specified in either paragraph (a)(1) or (a)(2) of this AD at 
the times specified in paragraphs (a)(1) and (a)(2) of this AD, as 
applicable.
    (1) Within 24 months after the effective date of this AD, do the 
actions specified in paragraph (c) of this AD.
    (2) Within 18 months after the effective date of this AD, do the 
actions in paragraph (b) of this AD; and within 72 months after the 
effective date of this AD, do the actions specified in paragraph (c) 
of this AD; except as provided by paragraph (a)(3) of this AD.
    (3) Model 747-400, -400D, and -400F series airplanes equipped 
with three air data computers (ADCs) are required to accomplish 
paragraph (a)(1) of this AD.

Optional Interim Action

    (b) Change the termination of the wires and perform an 
operational test, according to the Accomplishment Instructions of 
Boeing Special Attention Service Bulletin 747-31-2313, Revision 1, 
dated September 26, 2002 (for Model 747-400, -400D, and -400F series 
airplanes); Boeing Special Attention Service Bulletin 757-31-0068, 
Revision 1, dated August 29, 2002 (for Model 757-200, -200CB, and -
200PF series airplanes); and Boeing Special Attention Service 
Bulletin 767-31-0149, Revision 1, dated November 7, 2002 (for Model 
767-200, -300, and -300F series airplanes); as applicable.

Modification of Air Data Computer (ADC) System

    (c) Modify the ADC system, as specified in paragraph (c)(1), 
(c)(2), or (c)(3) of this AD, as applicable.
    (1) For Model 747-400, -400D, and -400F series airplanes: Re-
route wires associated with ADC overspeed warnings, replace the P1-1 
and P3-1 module assemblies in the flight deck with improved module 
assemblies, install various wires in and between the flight deck and 
main equipment center of the airplane, and perform a test of the 
source select module and a system functional test, according to the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
34A2460, Revision 2, dated June 14, 2001.

    Note 1: Boeing Service Bulletin 747-34A2460, Revision 2, refers 
to Boeing Component Service Bulletins 233U2200-31-01 and 233U2205-
31-01, both dated April 20, 1995, as additional sources for 
instructions to change the ADC computer source select switch on the 
P1-1 and P3-1 panels, respectively.

    (2) For Model 757-200, -200PF, and -200CB series airplanes: 
Install a circuit breaker and replace an existing lightplate 
assembly with a new, improved lightplate assembly in the flight 
compartment; install two relays and remove a certain relay in the 
main equipment center; make various wiring changes in the flight 
compartment and main equipment center; and perform tests of the 
flight data acquisition unit, flight data

[[Page 28057]]

recorder system, and stall and overspeed warnings. Do these actions 
according to the Accomplishment Instructions of Boeing Service 
Bulletin 757-34A0222, Revision 1, dated July 17, 2003.
    (3) For Model 767-200, -300, and -300F series airplanes: Modify 
the air data switching system and do a system functional test, 
according to the Accomplishment Instructions of Boeing Service 
Bulletin 767-34A0332, Revision 1, dated April 24, 2003.

Actions Required To Be Accomplished Prior to or Concurrently With 
Paragraph (c) of This AD

    (d) Prior to or concurrently with accomplishment of paragraph 
(c) of this AD, accomplish paragraph (d)(1) or (d)(2) of this AD, as 
applicable.
    (1) For Boeing Model 747-400, -400D, and -400F series airplanes: 
Do the actions specified in Table 2 of this AD, as applicable. Table 
2 of this AD follows:

           Table 2.--Boeing Model 747-400, -400D, and -400F Series Airplanes--Prior/Concurrent Actions
----------------------------------------------------------------------------------------------------------------
                                                                                           According to the
     For airplanes listed in--           Accomplish all actions associated with--           Accomplishment
                                                                                           Instructions of--
----------------------------------------------------------------------------------------------------------------
Boeing Service Bulletin 747-31-      Replacing the three Electronic Flight            Boeing Service Bulletin
 2179, dated May 26, 1994..           Information System (EFIS)/Engine Indicating      747-31-2179, dated May
                                      and Crew Alerting System (EICAS) interface       26, 1994.
                                      units (EIU) in the main equipment center with
                                      improved EIUs and installing new software in
                                      six integrated display units (IDU) and three
                                      EIUs.
Boeing Service Bulletin 747-31-      Replacing the three EIUs in the main equipment   Boeing Service Bulletin
 2180, dated March 17, 1994.          center with improved EIUs and installing new     747-31-2180, dated March
                                      software in six IDUs and three EIUs.             17, 1994.
Boeing Service Bulletin 747-31-      Installing new software in six IDUs and three    Boeing Service Bulletin
 2217, dated May 19, 1994.            EIUs.                                            747-31-2217, dated May
                                                                                       19, 1994.
Boeing Service Bulletins 747-31-     Replacing three EIUs with improved EIUs and      Boeing Service Bulletin
 2217, dated May 19, 1994; and 747-   installing new software in six IDUs and three    747-31-2178, dated July
 31-2178, dated July 1, 1993.         EIUs.                                            1, 1993.
Boeing Service Bulletins 747-31-     Replacing certain central maintenance computers  Boeing Service Bulletin
 2217, dated May 19, 1994; and 747-   (CMCs) with improved CMCs, modifying related     747-45-2005, dated
 45-2005, dated February 8, 1990.     wiring, and modifying the data loader control    February 8, 1990.
                                      panel.
Boeing Service Bulletins 747-31-     Installing new software in the CMC.............  Boeing Service Bulletin
 2217, dated May 19, 1994; and 747-                                                    747-45-2010, dated
 45-2010, dated December 17, 1992.                                                     December 17, 1992.
Boeing Service Bulletins 747-31-     Installing new software in six IDUs and three    Boeing Service Bulletin
 2217, dated May 19, 1994; and 747-   EIUs.                                            747-31-2163, dated
 31-2163, dated February 14, 1991.                                                     February 14, 1991.
----------------------------------------------------------------------------------------------------------------

Replacement of EICAS Computers

    (2) For airplanes listed in Table 1 of this AD that are also 
identified in any of the service bulletins listed in Table 3 of this 
AD: Prior to or concurrently with accomplishment of the actions 
required by paragraph (c) of this AD, accomplish all actions 
associated with replacing the existing EICAS computers with improved 
EICAS computers, according to the Accomplishment Instructions of the 
applicable service bulletin specified in Table 3 of this AD. The 
actions include performing an EICAS readout comparison to ensure 
that the applicable software is used; replacing the existing EICAS 
computers with new, improved EICAS computers that can be upgraded 
with certain software; and making related wiring changes. Table 3 of 
this AD follows:

                         Table 3.--Service Bulletins for Replacement of EICAS Computers
----------------------------------------------------------------------------------------------------------------
 Boeing Service Bulletin (all including   Service bulletin revision level--
        Appendices A, B, and C)--                                                  Service bulletin date--
----------------------------------------------------------------------------------------------------------------
757-31-0059.............................  Revision 3......................  March 29, 2001.
767-31-0091.............................  Revision 3......................  April 27, 2000.
767-31-0098.............................  Revision 2......................  October 21, 1999.
767-31-0099.............................  Revision 3......................  February 8, 2001.
767-31-0100.............................  Revision 2......................  July 29, 1999.
767-31-0101.............................  Original........................  July 6, 2000.
----------------------------------------------------------------------------------------------------------------

Parts Installation

    (e) As of the effective date of this AD, no person may install, 
on any airplane, a part having a part number listed in the 
``Existing Part Number'' column of the table under paragraph 2.E. of 
Boeing Alert Service Bulletins 757-31-0059, Revision 3, dated March 
29, 2001; 767-31-0091, Revision 3, dated April 27, 2000; 767-31-
0098, Revision 2, dated October 21, 1999; 767-31-0099, Revision 3, 
dated February 8, 2001; 767-31-0100, Revision 2, dated July 29, 
1999; or 767-31-0101, dated July 6, 2000; or under paragraph II.D. 
of Boeing Service Bulletins 747-31-2163, dated February 14, 1991; 
747-31-2178, dated July 1, 1993; 747-31-2179, dated May 26, 1994; 
747-31-2180, dated March 17, 1994; 747-45-2005, dated February 8, 
1990; or 747-45-2010, dated December 17, 1992.

[[Page 28058]]

Operator's ``Equivalent Procedure''

    (f) Where Boeing Alert Service Bulletin 747-34A2460, Revision 2, 
dated June 14, 2001; and Boeing Service Bulletin 757-34A0222, 
Revision 1, dated July 17, 2003; specify that certain actions may be 
accomplished per an operator's ``equivalent procedure'': These 
actions must be accomplished per the chapter of the applicable 
Boeing 747 or 757 Airplane Maintenance Manual specified in the 
applicable service bulletin. An operator's ``equivalent procedure'' 
cannot be used unless the operator receives FAA approval for that 
procedure according to paragraph (h) of this AD.

Actions Accomplished Per Previous Issue of Service Bulletins

    (g) Actions accomplished before the effective date of this AD 
per Boeing Alert Service Bulletin 757-34A0222, dated March 28, 2002; 
and Boeing Alert Service Bulletin 767-34A0332, dated January 10, 
2002; are considered acceptable for compliance with the 
corresponding actions specified in this AD.

Alternative Methods of Compliance

    (h) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

Incorporation by Reference

    (i) Unless otherwise specified in this AD, the actions shall be 
done in accordance with the service information included in Table 4, 
as follows:

                              Table 4.--Service Bulletins Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
             Boeing Service Bulletins                      Revision                          Date
----------------------------------------------------------------------------------------------------------------
Alert Service Bulletin 747-34A2460...............  2.......................  June 14, 2001.
Service Bulletin 747-31-2163.....................  Original................  February 14, 1991.
Service Bulletin 747-31-2178.....................  Original................  July 1, 1993.
Service Bulletin 747-31-2179.....................  Original................  May 26, 1994.
Service Bulletin 747-31-2180.....................  Original................  March 17, 1994.
Service Bulletin 747-31-2217.....................  Original................  May 19, 1994.
Service Bulletin 747-45-2005.....................  Original................  February 8, 1990.
Service Bulletin 747-45-2010.....................  Original................  December 17, 1992.
Service Bulletin 757-31-0059, including            3.......................  March 29, 2001.
 Appendices A, B, and C.
Service Bulletin 757-34A0222.....................  1.......................  July 17, 2003.
Service Bulletin 767-31-0091, including            3.......................  April 27, 2000.
 Appendices A, B, and C.
Service Bulletin 767-31-0098, including            2.......................  October 21, 1999.
 Appendices A, B, and C.
Service Bulletin 767-31-0099, including            3.......................  February 8, 2001.
 Appendices A, B, and C.
Service Bulletin 767-31-0100, including            2.......................  July 29, 1999.
 Appendices A, B, and C.
Service Bulletin 767-31-0101, including            Original................  July 6, 2000.
 Appendices A, B, and C.
Service Bulletin 767-34A0332.....................  1.......................  April 24, 2003.
Special Attention Service Bulletin 747-31-2313...  1.......................  September 26, 2002.
Special Attention Service Bulletin 757-31-0068...  1.......................  August 29, 2002.
Special Attention Service Bulletin 767-31-0149...  1.......................  November 7, 2002.
----------------------------------------------------------------------------------------------------------------

    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from Boeing Commercial Airplanes, 
P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Effective Date

    (j) This amendment becomes effective on June 22, 2004

    Issued in Renton, Washington, on May 5, 2004.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-10907 Filed 5-17-04; 8:45 am]
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