[Federal Register Volume 82, Number 45 (Thursday, March 9, 2017)]
[Proposed Rules]
[Pages 13079-13081]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-04598]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0128; Directorate Identifier 2016-NM-194-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 all 
The Boeing Company Model 737-300, -400, and -500 series airplanes. This 
proposed AD was prompted by a manufacturer's review that showed that 
the tank access door at a certain wing buttock line did not have an 
engineered ground path with the mating wing structure. This proposed AD 
would require replacing the tank access door, doing a check of the 
electrical bond, doing related investigative and corrective actions if 
necessary, and revising the maintenance or inspection program by 
incorporating an airworthiness limitation (AWL). We are proposing this 
AD to address the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by April 24, 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. Boeing 
Service Bulletin 737-57-1320, dated October 7, 2016, is also available 
on the Internet at http://www.regulations.gov by searching for and 
locating Docket No. FAA-2017-0128.

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-
0128; 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: Christopher Baker, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6498; 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-2017-0128; 
Directorate Identifier 2016-NM-194-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.

[[Page 13080]]

    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

    The manufacturer has reported that the tank access door at wing 
buttock line 191.00 did not have an engineered ground path with the 
mating wing structure. The current installation could become a 
potential ignition source in the event of a lightning strike. To date, 
there have been no reports of ignition in the fuel tank at this tank 
access door location that were caused by a lightning strike. An 
ungrounded path between the door and the mating wing structure, if not 
corrected, could result in an increased risk of ignition and subsequent 
fuel tank explosion in the event of a lightning strike.

Related Service Information Under 1 CFR Part 51

    We reviewed the following service information.
     Boeing Service Bulletin 737-57-1320, dated October 7, 
2016, which describes procedures for replacing the tank access door 
with a new installation that has two engineered ground paths between 
the new door assembly and the mating wing structure, doing a check of 
the electrical bond, and related investigative and corrective actions.
     Boeing 737-12345 Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs) D6-38278-CMR, dated May 
2016. The AWL required by this AD is AWL 28-AWL-30 ``Upper Wing Fuel 
Tank Access Panel--Lightning Protection Electrical Design Features,'' 
which describes features to verify during installation of the upper 
fuel tank access panel.
    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 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 accomplishing the actions specified 
in the service information described previously, except as discussed 
under ``Differences Between this Proposed AD and the Service 
Information.'' For information on the procedures and compliance times, 
see Boeing Service Bulletin 737-57-1320, dated October 7, 2016, at 
http://www.regulations.gov by searching for and locating Docket No. 
FAA-2017-0128.
    The phrase ``related investigative actions'' is used in this 
proposed AD. Related investigative actions are follow-on actions that 
(1) are related to the primary action, and (2) further investigate the 
nature of any condition found. Related investigative actions in an AD 
could include, for example, inspections.
    The phrase ``corrective actions'' is used in this proposed AD. 
Corrective actions correct or address any condition found. Corrective 
actions in an AD could include, for example, repairs.

Differences Between This Proposed AD and the Service Information

    Boeing Service Bulletin 737-57-1320, dated October 7, 2016, 
specifies to contact the manufacturer for certain instructions, but 
this proposed AD would require using repair methods, modification 
deviations, and alteration deviations in one of the following ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.

Costs of Compliance

    We estimate that this proposed AD affects 381 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
               Action                         Labor cost            Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Install new door assembly and check  12 work-hours x $85 per              $2,237          $3,257      $1,240,917
 electrical bond.                     hour = $1,020.
Revise maintenance or inspection     1 work-hour x $85 per hour                0              85          32,385
 program.                             = $85.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition actions specified in this proposed 
AD.
    According to the manufacturer, some of the costs of this proposed 
AD may be covered under warranty, thereby reducing the cost impact on 
affected individuals. We do not control warranty coverage for affected 
individuals. As a result, we have included all costs in our cost 
estimate.

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),

[[Page 13081]]

    (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-2017-0128; Directorate Identifier 
2016-NM-194-AD.

(a) Comments Due Date

    We must receive comments by April 24, 2017.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all The Boeing Company Model 737-300, -400, 
and -500 series airplanes, certificated in any category.

(d) Subject

    Air Transport Association (ATA) of America Code 57, Wings.

(e) Unsafe Condition

    This AD was prompted by a manufacturer's review that showed that 
the tank access door at wing buttock line 191.00 did not have an 
engineered ground path with the mating wing structure. We are 
issuing this AD to prevent an ungrounded path that could result in 
an increased risk of ignition and subsequent fuel tank explosion in 
the event of a lightning strike.

(f) Compliance

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

(g) New Door Assembly, Electrical Bond Check, and Related Corrective 
Actions

    At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Service Bulletin 737-57-1320, dated 
October 7, 2016, except as required by paragraph (i)(1) of this AD: 
Install a new door assembly, do a check of the electrical bond, and 
do all applicable related investigative and corrective actions, in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 737-57-1320, dated October 7, 2016, except as required by 
paragraph (i)(2) of this AD. Do all applicable related investigative 
and corrective actions before further flight.

(h) Revise the Maintenance or Inspection Program

    Prior to or concurrently with accomplishment of the actions 
required by paragraph (g) of this AD, or within 30 days after the 
effective date of this AD, whichever occurs later: Revise the 
maintenance or inspection program, as applicable, to incorporate 
Airworthiness Limitation 28-AWL-30, ``Upper Wing Fuel Tank Access 
Panel--Lightning Protection Electrical Design Features,'' as 
specified in Boeing 737-12345 Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs) D6-38278-CMR, dated 
May 2016.

(i) Service Information Exceptions

    (1) Where Boeing Service Bulletin 737-57-1320, dated October 7, 
2016, specifies a compliance time ``after the original issue date of 
this service bulletin,'' this AD requires compliance within the 
specified compliance time after the effective date of this AD.
    (2) Where Boeing Service Bulletin 737-57-1320, dated October 7, 
2016, specifies to contact Boeing for repair instructions, and 
specifies that action as Required for Compliance (RC), this AD 
requires repair using a method approved in accordance with the 
procedures specified in paragraph (j) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle 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 (k)(1) 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, 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 (i)(2) 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

    (1) For more information about this AD, contact Christopher 
Baker, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle 
Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, 
WA 98057-3356; phone: 425-917-6498; fax: 425-917-6590; email: 
[email protected].
    (2) 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 March 2, 2017.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-04598 Filed 3-8-17; 8:45 am]
 BILLING CODE 4910-13-P