[Federal Register Volume 82, Number 83 (Tuesday, May 2, 2017)]
[Proposed Rules]
[Pages 20450-20453]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-08831]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 82, No. 83 / Tuesday, May 2, 2017 / Proposed 
Rules  

[[Page 20450]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0332; Directorate Identifier 2016-NM-164-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain The Boeing Company Model 737-200, -200C, -300, -400, and -500 
series airplanes. This proposed AD was prompted by reports of skin 
doublers that disbonded from their skin panels. This proposed AD would 
require repetitive inspections of fuselage skin panels, and applicable 
on-condition actions. We are proposing this AD to address the unsafe 
condition on these products.

DATES: We must receive comments on this proposed AD by June 16, 2017.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, 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 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. It is also 
available on the Internet at http://www.regulations.gov by searching 
for and locating Docket No. FAA-2017-0332.

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-
0332; 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 proposed AD, the regulatory evaluation, any comments 
received, and other information. The street address for the Docket 
Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Wade Sullivan, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6430; fax: 425-917-6590; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2017-0332; 
Directorate Identifier 2016-NM-164-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    Fatigue damage can occur locally, in small areas or structural 
design details, or globally, in widespread areas. Multiple-site damage 
is widespread damage that occurs in a large structural element such as 
a single rivet line of a lap splice joining two large skin panels. 
Widespread damage can also occur in multiple elements such as adjacent 
frames or stringers. Multiple-site damage and multiple-element damage 
cracks are typically too small initially to be reliably detected with 
normal inspection methods. Without intervention, these cracks will 
grow, and eventually compromise the structural integrity of the 
airplane. This condition is known as widespread fatigue damage. It is 
associated with general degradation of large areas of structure with 
similar structural details and stress levels. As an airplane ages, 
widespread fatigue damage (WFD) will likely occur, and will certainly 
occur if the airplane is operated long enough without any intervention.
    The FAA's WFD final rule (75 FR 69746, November 15, 2010) became 
effective on January 14, 2011. The WFD rule requires certain actions to 
prevent structural failure due to WFD throughout the operational life 
of certain existing transport category airplanes and all of these 
airplanes that will be certificated in the future. For existing and 
future airplanes subject to the WFD rule, the rule requires that DAHs 
establish a limit of validity (LOV) of the engineering data that 
support the structural maintenance program. Operators affected by the 
WFD rule may not fly an airplane beyond its LOV, unless an extended LOV 
is approved.
    The WFD rule (75 FR 69746, November 15, 2010) does not require 
identifying and developing maintenance actions if the DAHs can show 
that such actions are not necessary to prevent WFD before the airplane 
reaches the LOV. Many LOVs, however, do depend on accomplishment of 
future maintenance actions. As stated in the WFD rule, any maintenance 
actions necessary to reach the LOV will be mandated by airworthiness 
directives through separate rulemaking actions.
    In the context of WFD, this action is necessary to enable DAHs to 
propose

[[Page 20451]]

LOVs that allow operators the longest operational lives for their 
airplanes, and still ensure that WFD will not occur. This approach 
allows for an implementation strategy that provides flexibility to DAHs 
in determining the timing of service information development (with FAA 
approval), while providing operators with certainty regarding the LOV 
applicable to their airplanes.
    We have received reports of skin doublers that disbonded from their 
skin panels on certain Model 737 series airplanes. Bonded skin doublers 
are part of the back-up structure for the skin panels and are installed 
from body station (BS) 259.50 through BS 1016 on both sides of the 
airplane. The airplane manufacturer has attributed the root cause of 
disbonded skin doublers to improper processing during the phosphoric 
acid anodization phase of skin panel manufacturing. Disbonding of the 
skin panel reduces the skin panel's capability to resist cracks in the 
countersunk holes of fastened joints and can lead to fuselage skin 
cracking and multi-site damage, predominantly in the lap splices and 
butt joints. Fuselage skin cracking resulting from disbonded skin 
panels, if not detected and corrected, could result in rapid 
decompression and loss of structural integrity of the airplane.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 737-53A1349, dated August 
23, 2016. The service information describes procedures for repetitive 
inspections of fuselage skin panels for cracking, corrosion, and 
existing disbond repairs; 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.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined that the unsafe condition described 
previously is likely to exist or develop in other products of the same 
type design.

Proposed AD Requirements

    This proposed AD would require accomplishment of the actions 
identified as ``RC'' (required for compliance) in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1349, dated August 
23, 2016, described previously, except for differences between this 
proposed AD and the service information that are identified in the 
regulatory text of this proposed AD.
    For information on the procedures and compliance times, see this 
service information at http://www.regulations.gov by searching for and 
locating Docket No. FAA-2017-0332.

Related Rulemaking

    AD 2003-14-06, Amendment 39-13225 (68 FR 40759, July 9, 2003; 
corrected July 21, 2003 (68 FR 42956)) (``AD 2003-14-06''), applies to 
certain Model 737-200, -200C, -300, -400, and -500 series airplanes. AD 
2003-14-06 requires repetitive inspections for cracking of certain lap 
splices, and corrective action if necessary. Accomplishment of initial 
inspections specified in this proposed AD would terminate all 
requirements of AD 2003-14-06.

Explanation of Certain Compliance Times

    The compliance time to replace skin panels, which is one of the 
actions identified as ``RC'' for certain conditions to address WFD in 
this NPRM, was established to ensure that discrepant structure is 
replaced before WFD develops in airplanes. Standard inspection 
techniques cannot be relied on to detect WFD before it becomes a hazard 
to flight. We will not grant any extensions of the compliance time to 
complete any AD-mandated service bulletin related to WFD without 
extensive new data that would substantiate and clearly warrant such an 
extension.
    Table 9 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-53A1349, dated August 23, 2016, does not provide a grace 
period for airplanes that have exceeded a certain compliance time. 
Paragraph (h)(3) of this proposed AD adds a grace period of 4,500 
flight cycles. We have coordinated this grace period with Boeing.

Costs of Compliance

    We estimate that this proposed AD affects 169 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
External general visual and        180 work-hours x                 $0  $15,300 per          $2,585,700 per
 detailed inspections.              $85 per hour =                       inspection cycle.    inspection cycle.
                                    $15,300 per
                                    inspection cycle.
External high frequency bond test  450 work hours x                  0  $38,250 inspection   $6,464,250 per
 inspection.                        $85 per hour =                       cycle.               inspection cycle.
                                    $38,250 per
                                    inspection cycle.
Ultrasonic disbond inspection and  630 work-hours x                  0  $53,550 per          $9,049,950 per
 internal detailed skin             $85 per hour =                       inspection cycle.    inspection cycle.
 inspection.                        $53,550 per
                                    inspection cycle.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary on-condition 
actions that would be required based on the results of the proposed 
inspections. We have no way of determining the number of aircraft that 
might need these on-condition actions:

                                        On-Condition Costs per Skin Panel
----------------------------------------------------------------------------------------------------------------
              Action                        Labor cost                Parts cost            Cost per product
----------------------------------------------------------------------------------------------------------------
On-condition inspections..........  Up to 25 work-hours x $85   $0...................  Up to $2,125.
                                     per hour = $2,125.
Repairs...........................  Up to 68 work-hours x $85   Up to $100...........  Up to $5,880.
                                     per hour = $5,780.

[[Page 20452]]

 
Skin panel replacement............  304 work-hours x $85 per    $95,000..............  $120,840.
                                     hour = $25,840.
----------------------------------------------------------------------------------------------------------------

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

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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):

The Boeing Company: Docket No. FAA-2017-0332; Directorate Identifier 
2016-NM-164-AD.

(a) Comments Due Date

    We must receive comments by June 16, 2017.

(b) Affected ADs

    This AD affects AD 2003-14-06, Amendment 39-13225 (68 FR 40759, 
July 9, 2003; corrected July 21, 2003 (68 FR 42956)) (``AD 2003-14-
06'').

(c) Applicability

    This AD applies to The Boeing Company Model 737-200, -200C, -
300, -400, and -500 series airplanes, certificated in any category, 
as identified in Boeing Alert Service Bulletin 737-53A1349, dated 
August 23, 2016.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of skin doublers that disbonded 
from their skin panels. We are issuing this AD to detect and correct 
disbonded skin panels, which could result in fuselage skin cracking, 
rapid decompression, and loss of structural integrity of the 
airplane.

(f) Compliance

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

(g) Actions Required for Compliance

    Except as required by paragraph (h) of this AD: Do all 
applicable actions identified as required for compliance (``RC'') 
in, and in accordance with, the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1349, dated August 23, 2016. Do 
the actions at the applicable times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1349, dated 
August 23, 2016.

(h) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Service Bulletin 737-53A1349, dated 
August 23, 2016, uses the phrase ``after the original issue 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 737-53A1349, dated 
August 23, 2016, specifies contacting Boeing for instructions, and 
specifies that action as ``RC'' (Required for Compliance): This AD 
requires using a method approved in accordance with the procedures 
specified in paragraph (k) of this AD.
    (3) For replaced skin panels identified in table 9 of paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-53A1349, 
dated August 23, 2016, on which the one-time internal inspection 
specified in Service Bulletin 737-53-1179, Revision 2, dated October 
25, 2001, has not been done: The compliance time for accomplishment 
of the actions specified in Part 8 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1349, dated 
August 23, 2016, is at the latest of the times specified in 
paragraphs (h)(3)(i), (h)(3)(ii), and (h)(3)(iii) of this AD.
    (i) Within 50,000 flight cycles after the skin panel 
replacement.
    (ii) Within 20,000 flight cycles after July 14, 2003 (the 
effective date of AD 2003-14-16).
    (iii) Within 4,500 flight cycles after the effective date of 
this AD.

(i) Terminating Action for This AD

    Accomplishment of any skin panel replacement, as specified in 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1349, dated August 23, 2016, except as required by paragraph 
(h)(2) of this AD, terminates the repetitive inspections required by 
paragraph (g) of this AD at the replaced skin panel only.

(j) Terminating Action for AD 2003-14-06

    Accomplishment of the initial inspections required by paragraph 
(g) of this AD terminates all requirements of AD 2003-14-06.

(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles Aircraft Certification Office, 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 paragraph (l)(1) of this AD. Information may

[[Page 20453]]

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, 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 paragraph (h)(2) of this AD: For 
service information that contains steps that are labeled as Required 
for Compliance (RC), the provisions of paragraphs (k)(4)(i) and 
(k)(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.

(l) Related Information

    (1) For more information about this AD, contact Wade Sullivan, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6430; fax: 425-917-6590; email: 
[email protected].
    (2) For information about AMOCs, contact Jennifer Tsakoumakis, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office (ACO), 3960 Paramount Boulevard, Lakewood, CA 90712-4137; 
phone: 562-627-5264; fax: 562-627-5210; email: 
[email protected].
    (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. You may view this 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.

    Issued in Renton, Washington, on April 24, 2017.
Paul Bernado,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-08831 Filed 5-1-17; 8:45 am]
 BILLING CODE 4910-13-P