
[Federal Register Volume 77, Number 152 (Tuesday, August 7, 2012)]
[Rules and Regulations]
[Pages 46943-46946]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-18583]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0480; Directorate Identifier 2010-NM-035-AD; 
Amendment 39-17139; AD 2012-15-10]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
The Boeing Company Model 747-400 and 747-400D series airplanes. This AD 
was prompted by a report of an in-flight multi-power system loss of the 
1, 2, and 3 alternating current electrical 
power systems located in the main equipment center (MEC). This AD 
requires installing aluminum gutter reinforcing brackets to the forward 
and aft drip shield gutters of the MEC; and adding a reinforcing 
fiberglass overcoat to the top surface of the MEC drip shield, 
including an inspection for cracking and holes in the MEC drip shield, 
and corrective actions if necessary. This AD also provides for an 
option to install an MEC drip shield drain system, which, if 
accomplished, would extend the compliance time for adding the 
reinforcing fiberglass overcoat to the top surface of the MEC drip 
shield. We are issuing this AD to prevent water penetration into the 
MEC, which could result in the loss of flight critical systems.

DATES: This AD is effective September 11, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of September 11, 
2012.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (phone: 800-647-5527) is Document Management Facility, 
U.S. Department of Transportation, Docket Operations, M-30, West 
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Francis Smith, Aerospace Engineer, 
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6596; fax: 425-917-6590; email: 
francis.smith@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a supplemental notice of proposed rulemaking (SNPRM) to 
amend 14 CFR part 39 to include an airworthiness directive (AD) that 
would apply to the specified products. That SNPRM published in the 
Federal Register on March 5, 2012 (77 FR 13043). The original NPRM (75 
FR 27966, May 19, 2010) proposed to require installing aluminum gutter 
reinforcing brackets to the forward and aft drip shield gutters of the 
MEC; and adding a reinforcing fiberglass overcoat to the top surface of 
the MEC drip shield, including an inspection for cracking and holes in 
the MEC drip shield, and corrective actions if necessary. That NPRM 
also provided for an option to install an MEC drip shield drain system, 
which, if accomplished, would extend the compliance time for adding the 
reinforcing fiberglass overcoat to the top surface of the MEC drip 
shield. The SNPRM proposed to revise the locating dimensions of the 
brackets and change the routing of the forward drain tubes.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
(77 FR 13043, March 5, 2012) and the FAA's response to each comment.

Concurrence With Supplemental NPRM (77 FR 13043, March 5, 2012)

    Boeing concurs with the contents of the proposed rule (77 FR 13043, 
March 5, 2012).

Request To Extend Compliance Time

    United Airlines (UAL) requested an extension of the compliance time 
from 24 months to 48 months to accomplish the actions in paragraph 
(g)(1) of the supplemental NPRM (77 FR 13043,

[[Page 46944]]

March 5, 2012). UAL stated that based on parts availability and its 
normal maintenance schedule, a 48-month compliance time would save 
costs and would allow time for the operators to perform the terminating 
action without having to perform the interim action, which would 
permanently add 26 lbs. to the airplane.
    We do not agree with the commenter's request to extend the 
compliance time. In developing an appropriate compliance time for this 
action, we considered the safety implications, parts availability, and 
normal maintenance schedules for the timely accomplishment of the 
modification. In consideration of these items, as well as the reports 
of multi-power system loss affecting flight-critical systems of an 
airplane in flight, we have determined that a 24-month compliance time 
will ensure an acceptable level of safety and allow the modifications 
to be done during scheduled maintenance intervals for most affected 
operators. The interim action is provided to give operators additional 
time to perform the more time-consuming action of accessing the 
necessary locations to perform the terminating action. We have not 
changed the AD in this regard.

Request To Reduce Compliance Time

    Cara Leigh Bitton (Weber State University) concurred with the 
actions proposed by the supplemental NPRM (77 FR 13043, March 5, 2012), 
but questioned why the compliance time would need to be extended for 
adding the reinforcing fiberglass overcoat to the top surface of the 
MEC drip shield, as required by paragraph (g)(2)(ii) of the 
supplemental NPRM. The commenter noted the risk and the importance to 
the passengers and crew of these airplanes. The commenter contended 
these changes should be made as soon as possible.
    We infer the commenter is requesting we reduce the compliance time 
in paragraph (g)(2)(ii) of this AD. We disagree with the commenter's 
request. In developing an appropriate compliance time for adding the 
reinforcing fiberglass overcoat to the top surface of the MEC drip 
shield, we considered the safety implications, parts availability, and 
normal maintenance schedules for timely accomplishment of replacement 
of the fasteners. Further, we arrived at the compliance time with 
operator and manufacturer concurrence.
    In consideration of these factors, we determined that the 
compliance time, as proposed and retained in this final rule, 
represents an appropriate interval in which operators can install the 
modification in a timely manner within the fleet, while still 
maintaining an adequate level of safety. Operators are always permitted 
to accomplish the requirements of an AD at a time earlier than the 
specified compliance time; therefore, an operator may choose to add the 
reinforcing fiberglass overcoat before the specified compliance time of 
96 months after the effective date of this AD.
    In addition, the purpose of two different compliance times is to 
provide a more immediate solution to the safety risk of cracked MEC 
drip shields by installing aluminum reinforcing brackets (i.e., an 
interim corrective action that specifies installing drains for the 
water to travel away from the MEC drip shield), and adding a 
reinforcing fiberglass overcoat to the top surface of the MEC drip 
shield (i.e., the long-term corrective action). Reducing the compliance 
time for the terminating action is not necessary based on the safety 
risk for affected operators of Model 747-400 and 747-400D airplanes. If 
additional data are presented that would justify a shorter compliance 
time, we may consider further rulemaking on this issue. However, we 
have not changed the AD in this regard.

Request To Correct Discrepancies

    An email thread between ST Aerospace and The Boeing Company was 
forwarded to the FAA by The Boeing Company as an ex parte request that 
we reference a pending service bulletin revision planned by The Boeing 
Company. The pending service bulletin will address discrepant 
quantities of nut plates and types of fasteners called out in Boeing 
Alert Service Bulletin 747-25A3555, Revision 1, dated July 27, 2011, 
which affects certain airplanes operated by ST Aerospace.
    We disagree that a change to the AD is needed, because the ST 
Aerospace configuration affects a very small number of the airplanes 
listed in Boeing Alert Service Bulletin 747-25A3555, Revision 1, dated 
July 27, 2011. Furthermore, doing the actions specified in Boeing Alert 
Service Bulletin 747-25A3555, Revision 1, dated July 27, 2011, 
addresses the identified unsafe condition. Operators are allowed to use 
different types of fasteners, as specified in Note 7. of paragraph 
3.A., ``Accomplishment Instructions,'' of Boeing Alert Service Bulletin 
747-25A3555, Revision 1, dated July 27, 2011. However, if an operator 
has a different airplane configuration that might use a different 
quantity of nut plates than what is specified in Boeing Alert Service 
Bulletin 747-25A3555, Revision 1, dated July 27, 2011, they may request 
an alternative method of compliance (AMOC) in accordance with paragraph 
(i) of the final rule. In addition, if a later revision of the 
referenced service bulletin is issued, affected operators may request 
approval to use a later revision as an AMOC, under the provisions of 
paragraph (i) of the final rule. We have not changed the AD in this 
regard.

Changes to the AD

    Boeing has issued Information Notice 747-25A3555 IN 04, dated 
February 10, 2012, to inform operators of airplanes in groups 1, 2 and 
3 of incorrect applicability tags specified in Boeing Alert Service 
Bulletin 747-25A3555, Revision 1, dated July 27, 2011. We have included 
this corrected information in new paragraph (h) of this AD, and changed 
the subsequent paragraph identifiers accordingly.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD as proposed except for minor editorial changes. We have 
determined that these minor changes:
     Are consistent with the intent that was proposed in the 
SNPRM (77 FR 13043, March 5, 2012) for correcting the unsafe condition; 
and
     Do not add any additional burden upon the public than was 
already proposed in the SNPRM (77 FR 13043, March 5, 2012).

Costs of Compliance

    We estimate that this AD affects 71 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

[[Page 46945]]



                                                 Estimated Costs
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                                                                                               Cost on U.S.
             Action                  Labor cost         Parts cost      Cost per product         operators
----------------------------------------------------------------------------------------------------------------
Install brackets...............  19 work-hours x    Up to $2,408 \1\.  Up to $4,023 \1\.  Up to $285,633.\1\
                                  $85 per hour =
                                  $1,615.
Add overcoat...................  63 work hours x    $1,731 ($577 x 3)  $7,086...........  $503,106.
                                  $85 per hour =
                                  $5,355.
Install optional MEC drip        22 work hours x    Up to $8,982 \1\.  Up to $10,852 \1\  Up to $770,492.\1\
 shield drain system.             $85 per hour =
                                  $1,870.
----------------------------------------------------------------------------------------------------------------
\1\ Depending on work package.

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.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD 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.
    For the reasons discussed above, I certify that this AD:
    (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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2012-15-10 The Boeing Company: Amendment 39-17139; Docket No. FAA-
2010-0480; Directorate Identifier 2010-NM-035-AD.

(a) Effective Date

    This AD is effective September 11, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-400 and 747-400D 
series airplanes; certificated in any category; as identified in 
Boeing Alert Service Bulletin 747-25A3555, Revision 1, dated July 
27, 2011.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 25, Equipment/Furnishings.

(e) Unsafe Condition

    This AD was prompted by a report of an in-flight multi-power 
system loss of the 1, 2, and 3 
alternating current electrical power systems located in the main 
equipment center (MEC). We are issuing this AD to prevent water 
penetration into the MEC, which could result in loss of flight 
critical systems.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Modification

    Except as required by paragraph (h) of this AD, do the actions 
specified in either paragraph (g)(1) or (g)(2) of this AD.
    (1) Within 24 months after the effective date of this AD, 
install aluminum reinforcing brackets on the MEC drip shield gutter, 
in accordance with Work Package 1 of the Accomplishment Instructions 
of Boeing Alert Service Bulletin 747-25A3555, Revision 1, dated July 
27, 2011; and add a reinforcing fiberglass overcoat to the top 
surface of the MEC drip shield, including doing a general visual 
inspection for cracking and holes in the top surface of the MEC drip 
shield, and doing all applicable corrective actions, in accordance 
with Work Package 3 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-25A3555, Revision 1, dated July 27, 2011. 
Do all applicable corrective actions before further flight after 
doing the general visual inspection.
    (2) Do the actions specified in paragraphs (g)(2)(i) and 
(g)(2)(ii) of this AD.
    (i) Within 24 months after the effective date of this AD, 
install aluminum reinforcing brackets on the MEC drip shield gutter, 
in accordance with Work Package 1 of the Accomplishment Instructions 
of Boeing Alert Service Bulletin 747-25A3555, Revision 1, dated July 
27, 2011; and install a MEC drip shield drain system, in accordance 
with Work Package 2 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-25A3555, Revision 1, dated July 27, 2011.
    (ii) Within 96 months after the effective date of this AD, add a 
reinforcing fiberglass overcoat to the top surface of the MEC drip 
shield, including doing a general visual inspection for cracking and 
holes in the top surface of the MEC drip shield, and doing all 
applicable corrective actions, in accordance with Work Package 3 of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-25A3555, Revision 1, dated July 27, 2011. Do all applicable 
corrective actions before further flight after doing the general 
visual inspection.

(h) Exceptions

    (1) Boeing Alert Service Bulletin 747-25A3555, Revision 1, dated 
July 27, 2011, states that Figures 7 and 8 apply to airplanes in 
Groups 1 and 3; however, Figures 7 and 8 apply to Group 2 airplanes.
    (2) Boeing Alert Service Bulletin 747-25A3555, Revision 1, dated 
July 27, 2011, states that Figures 9 and 10 apply to airplanes in 
Group 2; however, Figures 9 and 10 apply to Groups 1 and 3 
airplanes.
    (3) Where Paragraph 1., ``Kits/Parts,'' of Paragraph 2.C., 
``Parts Necessary for Each Airplane,'' of Boeing Alert Service 
Bulletin 747-25A3555, Revision 1, dated July 27, 2011, states that 
Groups 1 and 3 airplanes require top kits 015U1854-1 and 015U1854-

[[Page 46946]]

2, Groups 1 and 3 airplanes require top kits 015U1854-3 and 
015U1854-4.
    (4) Where Paragraph 1., ``Kits/Parts,'' of Paragraph 2.C., 
``Parts Necessary for Each Airplane,'' of Boeing Alert Service 
Bulletin 747-25A3555, Revision 1, dated July 27, 2011, states that 
Group 2 airplanes require top kits 015U1854-3 and 015U1854-4, Group 
2 airplanes require top kits 015U1854-1 and 015U1854-2.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(j) Related Information

    For more information about this AD, contact Francis Smith, 
Aerospace Engineer, Cabin Safety and Environmental Systems Branch, 
ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue SW., Renton, WA 98057-3356; phone: 425-917-6596; fax: 425-
917-6590; email: francis.smith@faa.gov.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Alert Service Bulletin 747-25A3555, Revision 1, dated 
July 27, 2011.
    (ii) Reserved.
    (3) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com.
    (4) You may review copies of the referenced service information 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., 
Renton, WA. For information on the availability of this material at 
the FAA, call 425-227-1221.
    (5) You may also review copies of the service information that 
is incorporated by reference 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/cfr/ibr-locations.html.

    Issued in Renton, Washington, on July 20, 2012.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-18583 Filed 8-6-12; 8:45 am]
BILLING CODE 4910-13-P


