[Federal Register Volume 83, Number 28 (Friday, February 9, 2018)]
[Rules and Regulations]
[Pages 5685-5689]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-01807]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0630; Product Identifier 2017-NM-058-AD; Amendment 
39-19173; AD 2018-02-20]
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 777-200, -200LR, -300, and -300ER series 
airplanes. This AD was prompted by reports of corrosion in the aft 
fuselage. This AD requires a one-time review of the operator's 
maintenance procedures, repetitive detailed internal and external 
inspections for corrosion or cracking, and applicable on-condition 
actions. This AD also includes an optional terminating action for the 
inspections. We are issuing this AD to address the unsafe condition on 
these products.

DATES: This AD is effective March 16, 2018.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 16, 
2018.

ADDRESSES: For service information identified in this final rule, 
contact Boeing Commercial Airplanes, Attention: Contractual & Data 
Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 
90740-5600; telephone: 562-797-1717; internet: https://www.myboeingfleet.com. You may view this service information at the 
FAA, Transport Standards Branch, 1601 Lind Avenue SW, Renton, WA. For 
information on the availability of this material at the FAA, call 425-
227-1221. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-
0630.

Examining the AD Docket

    You may examine the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-
0630; 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 final rule, the regulatory evaluation, any comments 
received, and other information. The address for the

[[Page 5686]]

Docket Office (phone: 800-647-5527) is Docket 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: Eric Lin, Aerospace Engineer, Airframe 
Section, FAA, Seattle ACO Branch, 1601 Lind Avenue SW, Renton, WA 
98057-3356; phone: 425-917-6412; fax: 425-917-6590; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to certain The Boeing Company 
Model 777-200, -200LR, -300, and -300ER series airplanes. The NPRM 
published in the Federal Register on July 14, 2017 (82 FR 32507). The 
NPRM was prompted by reports of corrosion in the aft fuselage. The NPRM 
proposed to require a one-time review of the operator's maintenance 
procedures, repetitive detailed internal and external inspections for 
corrosion or cracking, and applicable on-condition actions. The NPRM 
also included an optional terminating action for the inspections.
    We are issuing this AD to detect and correct untreated vacuum waste 
system spills or leaks, which could cause corrosion of the airplane 
structure, which could lead to fatigue cracks, and could ultimately 
result in rapid decompression and loss of structural integrity.

Comments

    We gave the public the opportunity to participate in developing 
this final rule. The following presents the comments received on the 
NPRM and the FAA's response to each comment.

Support for the NPRM

    Boeing expressed its support for the NPRM.

Request To Extend the Inspection Compliance Time

    Cathay Pacific expressed concern that it would not be able to 
demonstrate that it has performed an acceptable records review, which 
is required to demonstrate that all prior vacuum waste system spills or 
leaks were cleaned and neutralized using the acceptable procedure. 
Cathay Pacific noted that some airplanes in its fleet have been in 
service for more than 20 years, so an older record could easily be 
missed when doing this review. Cathay Pacific stated that because of 
this concern, it has opted to treat all airplanes as having inadequate 
records and perform inspections on them. Cathay Pacific stated that the 
applicable inspection compliance times do not allow waiting for the 
next scheduled maintenance check, leading to additional downtime.
    We infer that Cathay Pacific is requesting that we extend the 
compliance time for the initial and repetitive inspections. We disagree 
with the commenter's request. We have determined that the compliance 
times specified in this AD are necessary to address the identified 
unsafe condition. However, under the provisions of paragraph (j) of 
this AD, we will consider requests for approval of an alternative 
method of compliance (AMOC), including extension of the compliance 
times, if sufficient data is submitted to substantiate that a different 
compliance time will provide an acceptable level of safety. We have not 
changed this AD in this regard.

Request To Extend the Compliance Times for Certain Airplanes

    United Airlines (UAL) and Air France (AF) requested that we revise 
the compliance times for airplanes on which certain inspections have 
been done. UAL requested that the compliance time be extended for 
airplanes on which corrosion prevention and control program (CPCP) 
inspections have already been done. UAL noted that many operators have 
proven corrosion control programs that do not have corrosion findings 
greater than CPCP level 1, which mitigates the corrosion risk factor. 
UAL suggested that the initial inspection compliance time be extended 
for airplanes on which maintenance records show that no corrosion 
findings greater than CPCP level 1 have occurred in the inspection area 
in the 10 years prior to the effective date of the AD.
    AF requested that the compliance times be extended for airplanes on 
which maintenance planning document (MPD) inspections have been done. 
AF noted that existing MPD items require general visual inspections of 
certain areas below the aft and bulk cargo compartment floor panels. AF 
stated that because the majority of its fleet has already been 
inspected under the MPD items, the compliance times in the NPRM are too 
restrictive. AF noted that the initial compliance times cannot be 
accommodated into its 777 C or heavy checks interval. AF suggested 
compliance times based on the number of days since the date of issuance 
of the original airworthiness certificate or date of issuance of the 
original export certificate of airworthiness instead of days after the 
effective date of the AD as specified in the proposed AD.
    We disagree with the commenters' requests to extend the compliance 
times. The CPCP has three different levels of corrosion damage, as 
defined within the MPD, based on the severity and frequency of 
corrosion findings and requires operators to adjust their individual 
programs to limit corrosion findings to level 1 if they have level 2 or 
higher findings. However, operators have reported finding recurring 
corrosion damage in-between scheduled CPCP or MPD inspections that was 
due to untreated vacuum waste system residue. Additionally, we have 
reviewed the existing MPD inspections and have determined that the MPD 
inspections do not repeat at adequate intervals to address the unsafe 
condition. The determinations of the unsafe condition, mitigating 
actions, and compliance times were coordinated with the manufacturer. 
Under the provisions of paragraph (j) of this AD, we will consider 
requests for approval of AMOCs, including extensions of the compliance 
times, if sufficient data, such as an operator's individual CPCP and 
practices for treating vacuum waste system residue, is submitted to 
substantiate that a different compliance time will provide an 
acceptable level of safety. We have not changed this AD in this regard.

Request To Allow the Use of a Different Sodium Bicarbonate Compound

    Japan Airlines (JAL) and AF requested that we revise the NPRM to 
allow the use of a different sodium bicarbonate compound than the ASTM 
D928 specified in Boeing Alert Service Bulletin 777-53A0083, dated 
April 20, 2017. JAL noted it had difficulty finding the specified 
sodium bicarbonate compound, but could find an equivalent product. AF 
noted that is has a corresponding product.
    We partially agree with the commenters' request. We agree that an 
equivalent sodium bicarbonate compound is acceptable. Boeing has issued 
Boeing Information Notice 777-53A0083 IN 01, dated September 1, 2017, 
to clarify that a commercially available sodium bicarbonate compound is 
acceptable for compliance. However, we do not agree to revise this AD 
because it does not require the use of ASTM D928 sodium bicarbonate 
compound. As indicated in the Accomplishment Instructions and Figure 2 
of Boeing Alert Service Bulletin 777-53A0083, dated April 20, 2017, 
sodium bicarbonate must be used, but a specific compound type is not 
identified.

[[Page 5687]]

Request To Define a Neutral pH

    American Airlines (AAL) requested that we revise the NPRM to define 
a neutral pH as one that has a value between 6.5 and 8.5, to account 
for natural variations in tap water. AAL stated that the NPRM does not 
define a tolerance from the common definition of neutral pH, which is a 
pH of 7.
    We disagree with the commenter's request. Paragraph 3.A., General 
Information, Note 19, of Boeing Alert Service Bulletin 777-53A0083, 
dated April 20, 2017, defines neutralization as making the vacuum waste 
system spill or leak contents non-acidic or non-corrosive. No specific 
pH value is defined in the service information or required by this AD. 
Therefore, operators can include tolerances for a neutral pH. One way 
for operators to account for pH variances of their local clean water 
supply is to measure the pH level of their clean water supply in order 
to establish a baseline pH level, that can then be used to compare 
against samples taken from the fuselage structure. We have not changed 
this AD in this regard.

Request To Define a Standard Litmus Paper

    AAL and Cathay Pacific requested that we revise the NPRM to define 
a standard part number for the litmus paper to use in determining if 
the acid is neutralized. AAL noted that the NPRM does not specify a 
resolution or range for the litmus paper. Cathay Pacific claimed that 
because Boeing Alert Service Bulletin 777-53A0083, dated April 20, 
2017, does not list a specific litmus paper, the instruction to ``use 
litmus paper'' is ambiguous and operators would not be able to 
determine if an acceptable litmus paper is used.
    We disagree with the commenters' request. Litmus paper is a 
commonly available tool. Accomplishing the cleaning and neutralization 
steps in Boeing Alert Service Bulletin 777-53A0083, dated April 20, 
2017, does not specify the use of a specific brand or type of litmus 
paper. We have not changed this AD in this regard.

Request To Define the Location and Quantity of Litmus Paper Testing 
Points

    AAL and Cathay Pacific requested that we revise the NPRM to define 
the locations where litmus paper testing must be done, as well as the 
number of samples that must be taken. AAL pointed out that the 
structural features that must be chemically neutralized are specified 
in Boeing Alert Service Bulletin 777-53A0083, dated April 20, 2017, 
while the litmus paper testing spots are not. Cathay Pacific suggested 
that Boeing Alert Service Bulletin 777-53A0083, dated April 20, 2017, 
implies that operators should do litmus paper testing on all the 
structural features in the inspection and neutralization area, but 
stated it does not believe this is the intent.
    We agree to provide clarification on the number and location of 
litmus paper testing spots and confirm that paragraph (i) of this AD 
does not require testing with litmus paper at all structural features 
in the neutralization area. However, we do not agree that it is 
necessary to provide a specific number of samples or testing locations. 
The objective of the litmus paper testing is to verify that there are 
no remaining acidic or corrosive substances on the structure. The 
appropriate level of testing may vary between airplanes depending on 
factors such as maintenance records, previous spills or leaks, or 
repairs that obstruct access. Samples should be tested at enough 
locations within the affected area of the structure for the operator to 
determine that there are no residual acidic or corrosive contents on 
primary structural elements in the inspection area, including any 
locations where the sodium bicarbonate solution visibly reacted when 
applied, which indicates the presence of acidic or corrosive 
substances, and any locations where there are signs of corrosion 
damage. We have not changed this AD in this regard.

Request To Allow the Use of Alternative Corrosion Inhibiting Compounds

    AAL requested that we allow the use of alternative corrosion 
inhibiting compounds (which are applied to the cleaned and neutralized 
areas as part of the required restoration) as specified in Boeing 
Aircraft Maintenance Manual (AMM) Task 51-05-01-210-803. AAL noted that 
Boeing Alert Service Bulletin 777-53A0083, dated April 20, 2017, 
specifies BMS3-29 compound and does not allow the use of alternative 
compounds.
    We agree with the commenter's request. Boeing AMM Task 51-05-01-
210-803 specifies the application of a single coat of water displacing/
anti-corrosion compound BMS3-29 or BMS3-35 at a minimum, with an option 
to layer different compounds in areas with high potential for severe 
corrosion. We have added paragraph (h)(3) of this AD to specify 
acceptable alternative corrosion inhibiting compounds.

Request To Update the Costs of Compliance

    Cathay Pacific requested that we update the work-hours estimate for 
cleaning and neutralization in the NPRM. Cathay Pacific stated that the 
area to be neutralized covers 13 frames and 15 stringers, so it will 
require more work-hours to complete this task.
    We disagree with the commenter's request. The work-hours estimate 
is determined by Boeing and provided for informational and planning 
purposes only. In addition, Cathay Pacific did not provide any 
alternative estimates for the work-hours. We have not changed this AD 
in this regard.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this final rule with the changes described previously and minor 
editorial changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM for correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this final 
rule.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 777-53A0083, dated April 
20, 2017. The service information describes procedures for a one-time 
review of the operator's maintenance procedures, repetitive detailed 
internal and external inspections for corrosion or cracking, cleaning 
and neutralization of the internal inspection area (an optional 
terminating action), and applicable on-condition actions. This service 
information is reasonably available because the interested parties have 
access to it through their normal course of business or by the means 
identified in the ADDRESSES section.

Costs of Compliance

    We estimate that this AD affects 161 airplanes of U.S. registry. 
The cost to review an operator's maintenance procedures varies 
depending on the operator's recordkeeping system and fleet size so we 
did not include a specific estimate for that action. We estimate the 
following costs to comply with the remaining actions of this AD:

[[Page 5688]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                Cost on U.S.
            Action                   Labor cost         Parts cost      Cost per  product         operators
----------------------------------------------------------------------------------------------------------------
Inspections...................  75 work-hours x $85               $0  $6,375 per            $1,026,375 per
                                 per hour = $6,375                     inspection cycle.     inspection cycle.
                                 per inspection
                                 cycle.
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                                Estimated Costs for Optional Terminating Actions
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                                                                                                     Cost per
                   Action                                 Labor cost                Parts cost        product
----------------------------------------------------------------------------------------------------------------
Cleaning and neutralization................  30 work-hours x $85 per hour =                   $0          $2,550
                                              $2,550.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition actions specified in this AD.

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.
    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to transport category airplanes to 
the Director of the System Oversight Division.

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):

2018-02-20 The Boeing Company: Amendment 39-19173; Docket No. FAA-
2017-0630; Product Identifier 2017-NM-058-AD.

(a) Effective Date

    This AD is effective March 16, 2018.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 777-200, -200LR, -
300, and -300ER series airplanes, certificated in any category, as 
identified in Boeing Alert Service Bulletin 777-53A0083, dated April 
20, 2017.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of corrosion in the aft 
fuselage. We are issuing this AD to detect and correct untreated 
vacuum waste system spills or leaks, which could cause corrosion of 
the airplane structure, which could lead to fatigue cracks, and 
could ultimately result in rapid decompression and loss of 
structural integrity.

(f) Compliance

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

(g) Required Actions

    Except as required by paragraphs (h)(1) through (h)(3) of this 
AD: At the applicable times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 777-53A0083, dated 
April 20, 2017, do all applicable actions identified as ``RC'' 
(required for compliance) in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Service Bulletin 777-
53A0083, dated April 20, 2017.

(h) Exceptions To Service Information Specifications

    (1) Where Boeing Alert Service Bulletin 777-53A0083, dated April 
20, 2017, uses the phrase ``after the original issue date of this 
service bulletin,'' for purposes of determining compliance with the 
requirements of this AD, the phrase ``after the effective date of 
this AD'' must be used.
    (2) Where Boeing Alert Service Bulletin 777-53A0083, dated April 
20, 2017, specifies contacting Boeing, and specifies that action as 
RC: This AD requires using a method approved in accordance with the 
procedures specified in paragraph (j) of this AD.
    (3) Where Boeing Alert Service Bulletin 777-53A0083, dated April 
20, 2017, specifies to apply corrosion inhibiting compound BMS3-29 
to the cleaned and neutralized area, and specifies that action as 
RC: This AD allows operators to apply BMS3-29, BMS3-35, or a base 
coat of BMS3-29 or BMS3-35 with a top coat of BMS3-26.

[[Page 5689]]

(i) Optional Terminating Action for Repetitive Inspections

    Accomplishment of ``PART 5: CLEANING AND NEUTRALIZATION,'' as 
specified in the Accomplishment Instructions of Boeing Alert Service 
Bulletin 777-53A0083, dated April 20, 2017, terminates the 
repetitive inspections required by paragraph (g) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO Branch, 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 certification office, send it to the attention of the 
person identified in paragraph (k) of this AD. Information may be 
emailed to: [email protected].
    (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.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle ACO Branch, to make those findings. To be approved, 
the repair method, modification deviation, or alteration deviation 
must meet the certification basis of the airplane, and the approval 
must specifically refer to this AD.
    (4) Except as required by paragraphs (h)(2) and (h)(3) of this 
AD: For service information that contains steps that are labeled as 
Required for Compliance (RC), the provisions of paragraphs (j)(4)(i) 
and (j)(4)(ii) of this AD apply.
    (i) The steps labeled as RC, including substeps under an RC step 
and any figures identified in an RC step, must be done to comply 
with the AD. If a step or substep is labeled ``RC Exempt,'' then the 
RC requirement is removed from that step or substep. An AMOC is 
required for any deviations to RC steps, including substeps and 
identified figures.
    (ii) Steps not labeled as RC may be deviated from using accepted 
methods in accordance with the operator's maintenance or inspection 
program without obtaining approval of an AMOC, provided the RC 
steps, including substeps and identified figures, can still be done 
as specified, and the airplane can be put back in an airworthy 
condition.

(k) Related Information

    For more information about this AD, contact Eric Lin, Aerospace 
Engineer, Airframe Section, FAA, Seattle ACO Branch, 1601 Lind 
Avenue SW, Renton, WA 98057-3356; phone: 425-917-6412; fax: 425-917-
6590; email: [email protected].

(l) 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 777-53A0083, dated April 20, 
2017.
    (ii) Reserved.
    (3) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Contractual & Data Services 
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
5600; telephone: 562-797-1717; internet: https://www.myboeingfleet.com.
    (4) You may view this service information at the FAA, Transport 
Standards Branch, 1601 Lind Avenue SW, Renton, WA. For information 
on the availability of this material at the FAA, call 425-227-1221.
    (5) You may view this 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 January 19, 2018.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2018-01807 Filed 2-8-18; 8:45 am]
 BILLING CODE 4910-13-P