Document ID: FAA-2019-0524-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2019-07-12T04:00Z

[Federal Register Volume 84, Number 134 (Friday, July 12, 2019)]
[Proposed Rules]
[Pages 33189-33191]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-14878]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0524; Product Identifier 2019-NM-081-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain The Boeing Company Model 747-400 and 747-400F series 
airplanes. This proposed AD was prompted by an evaluation that 
determined fatigue cracks could develop in the underwing longerons. 
This proposed AD would require repetitive inspections of the underwing 
longerons and certain fuselage skins for any crack, and applicable on-
condition actions. The FAA is proposing this AD to address the unsafe 
condition on these products.

DATES: The FAA must receive comments on this proposed AD by August 26, 
2019.

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 
Standards Branch, 2200 South 216th St., Des Moines, WA. For information 
on the availability of this material at the FAA, call 206-231-3195. It 
is also available on the internet at http://www.regulations.gov by 
searching for and locating Docket No. FAA-2019-0524.

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-2019-
0524; or in person at Docket Operations between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays. The AD docket contains 
this NPRM, the regulatory evaluation, any comments received, and other 
information. The street address for Docket Operations is listed above. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Eric Lin, Aerospace Engineer, Airframe 
Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 
98198; phone and fax: 206-231-3523; email: eric.lin@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    The FAA invites 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-2019-0524; 
Product Identifier 2019-NM-081-AD'' at the beginning of your comments. 
The FAA specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this NPRM. The FAA will 
consider all comments received by the closing date and may amend this 
NPRM because of those comments.
    The FAA will post all comments received, without change, to http://

[[Page 33190]]

www.regulations.gov, including any personal information you provide. 
The FAA will also post a report summarizing each substantive verbal 
contact received about this proposed AD.

Discussion

    The FAA received reports of fatigue cracks in the underwing 
longerons of multiple Model 777 airplanes. A cross-model evaluation 
determined that Model 747-400 and 747-400F series airplanes are subject 
to the same unsafe condition. (The FAA issued a similar AD [AD 2017-16-
10, Amendment 39-18987 (82 FR 39513, August 21, 2017)] for Model 777 
airplanes.) The cracks initiate at the forward fastener row joining the 
longeron to the wing lower surface. Cracking of the forward fuselage 
skins was also found. Model 747-400 line numbers 1308, 1313, and 1315 
through 1419 inclusive, have a similar one-piece machined design and 
similar stress levels as those on the Model 777 underwing longerons; 
however, no cracks have been reported on the Model 747-400 one-piece 
longerons. Cracking in an underwing longeron, if not addressed, could 
result in fuel leakage into the pressurized fuselage and increase the 
risk of a fire. Cracking in the adjacent fuselage skin could result in 
rapid decompression. Either condition could adversely affect the 
structural integrity of the airplane.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 747-53A2900 RB, 
dated April 11, 2019. The service information describes procedures for 
repetitive detailed inspections and ultrasonic inspections of the 
underwing longerons and the adjacent fuselage skin, and ultrasonic and 
surface high frequency eddy current (HFEC) inspections of certain 
fuselage skins, on the left and right sides of the airplane, for any 
crack, and applicable on-condition actions. On-condition actions 
include repair.
    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

    The FAA is proposing this AD because the agency 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 accomplishment of the actions 
identified in Boeing Alert Requirements Bulletin 747-53A2900 RB, dated 
April 11, 2019, described previously, except for any differences 
identified as exceptions 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-2019-0524.

Costs of Compliance

    The AD estimates that this proposed AD affects 20 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this 
proposed AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Detailed inspections of the        2 work-hours x $85               $0  $170 per inspection  $3,400 per
 underwing longerons.               per hour = $170                      cycle.               inspection cycle.
                                    per inspection
                                    cycle.
Ultrasonic and HFEC inspections    9 work-hours x $85                0  $765 per inspection  $15,300 per
 of the adjacent fuselage skin.     per hour = $765                      cycle.               inspection cycle.
                                    per inspection
                                    cycle.
Ultrasonic inspections of the      2 work-hours x $85                0  $170 per inspection  $3,400 per
 underwing longerons.               per hour = $170                      cycle.               inspection cycle.
                                    per inspection
                                    cycle.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data that would enable us to 
provide cost estimates for the on-condition actions specified in this 
proposed 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.
    The FAA is 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 proposed 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 and associated appliances to the 
Director of the System Oversight Division.

Regulatory Findings

    The FAA 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) Will not affect intrastate aviation in Alaska, 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.

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,

[[Page 33191]]

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-2019-0524; Product Identifier 
2019-NM-081-AD.

(a) Comments Due Date

    The FAA must receive comments by August 26, 2019.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-400 and 747-400F 
series airplanes, certificated in any category, as identified in 
Boeing Alert Requirements Bulletin 747-53A2900 RB, dated April 11, 
2019.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by an evaluation that determined fatigue 
cracks could develop in the underwing longerons. The FAA is issuing 
this AD to address cracks in the underwing longerons, which could 
result in fuel leakage into the pressurized fuselage and increase 
the risk of a fire, and to address cracks in the adjacent fuselage 
skin, which could result in rapid decompression. Either condition 
could adversely affect the structural integrity of the airplane.

(f) Compliance

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

(g) Required Actions

    Except as specified by paragraph (h) of this AD: At the 
applicable times specified in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 747-53A2900 RB, dated April 11, 2019, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
747-53A2900 RB, dated April 11, 2019.

    Note 1 to paragraph (g):  Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
747-53A2900, dated April 11, 2019, which is referred to in Boeing 
Alert Requirements Bulletin 747-53A2900 RB, dated April 11, 2019.

(h) Exceptions to Service Information Specifications

    (1) For purposes of determining compliance with the requirements 
of this AD: Where Boeing Alert Requirements Bulletin 747-53A2900 RB, 
dated April 11, 2019, uses the phrase ``the original issue date of 
Requirements Bulletin 747-53A2900 RB,'' this AD requires using ``the 
effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 747-53A2900 RB, 
dated April 11, 2019, specifies contacting Boeing for repair 
instructions: This AD requires doing the repair using a method 
approved in accordance with the procedures specified in paragraph 
(i) of this AD.

(i) 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 (j)(1) of this AD. Information may be 
exception occurred on : 2019-14878.htm
exception occurred on : 2019-14878.htm
emailed to: 9-ANM-Seattle-ACO-AMOC-Reque[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 Company Organization Designation 
Authorization (ODA) that has been authorized by the Manager, Seattle 
ACO Branch, FAA, 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.

(j) Related Information

    (1) For more information about this AD, contact Eric Lin, 
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 
South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3523; 
email: eric.lin@faa.gov.
    (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 Standards Branch, 2200 South 216th 
St., Des Moines, WA. For information on the availability of this 
material at the FAA, call 206-231-3195.

    Issued in Des Moines, Washington, on July 2, 2019.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2019-14878 Filed 7-11-19; 8:45 am]
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