Document ID: FAA-2018-0504-0004
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2018-09-28T04:00Z

[Federal Register Volume 83, Number 189 (Friday, September 28, 2018)]
[Rules and Regulations]
[Pages 48927-48930]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-20918]

[[Page 48927]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0504; Product Identifier 2018-NM-046-AD; Amendment 
39-19433; AD 2018-19-32]
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 all The 
Boeing Company Model 707, 720, and 720B series airplanes. This AD was 
prompted by a report indicating that a fracture of the midspar fitting 
resulted in the separation of the inboard strut and engine from the 
airplane, and a determination that existing inspections are not 
sufficient for timely detection of cracking. This AD requires 
repetitive inspections of certain nacelle strut spar and overwing 
fittings, and diagonal braces and associated fittings; replacement of 
the diagonal brace assembly on certain airplanes; and applicable 
related investigative and corrective actions. We are issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective November 2, 2018.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of November 2, 
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, 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-2018-
0504.

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-2018-
0504; 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 final rule, the regulatory evaluation, any comments received, and 
other information. The address for Docket Operations (phone: 800-647-
5527) is 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: Jeffrey Chang, Aerospace Engineer, 
Propulsion Section, FAA, Los Angeles ACO Branch, 3960 Paramount 
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5263; fax: 562-627-
5210; email: [email protected]; or George Garrido, Aerospace 
Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount 
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5232; fax: 562-627-
5210; 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 all The Boeing Company 
Model 707, 720, and 720B series airplanes. The NPRM published in the 
Federal Register on June 7, 2018 (83 FR 26383). The NPRM was prompted 
by a report indicating that a fracture of the midspar fitting resulted 
in the separation of the inboard strut and engine from the airplane, 
and a determination that existing inspections are not sufficient for 
timely detection of cracking. The NPRM proposed to require repetitive 
inspections of certain nacelle strut spar and overwing fittings, and 
diagonal braces and associated fittings; replacement of the diagonal 
brace assembly on certain airplanes; and applicable related 
investigative and corrective actions.
    We are issuing this AD to address cracks, which if not detected and 
corrected, could grow beyond a critical length, allowing the strut 
fitting to fail and reducing the structural integrity of the nacelle. 
This, in combination with damage to adjacent attachment structure, 
could result in the loss of an engine from the airplane.

Comments

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

Request To Clarify Service Information Used for Oversizing Certain 
Holes

    Boeing requested that we revise paragraph (k) of the proposed AD to 
specify outboard diagonal brace end fitting (forward or aft) attach 
holes that have been oversized as specified in Boeing 707 Alert Service 
Bulletin A3364, ``Revision 3, dated May 29, 1981,'' rather than 
``Revision 4, dated February 21, 2017.'' Boeing noted that Boeing 707 
Alert Service Bulletin A3364, Revision 4, dated February 21, 2017, does 
not contain instructions for oversizing the attach holes, but instead 
refers to oversizing done as specified in Revision 3. Boeing added 
that, as written, the proposed AD would not require operators to 
replace a diagonal brace assembly with attach holes that were oversized 
as specified in Boeing 707 Alert Service Bulletin A3364, Revision 3, 
dated May 29, 1981, potentially allowing an unsafe condition to 
continue.
    We agree with the commenter's request. We have revised paragraph 
(k) of this AD to specify ``. . . outboard diagonal brace end fitting 
(forward or aft) attach holes have been oversized as specified in 
Boeing 707 Alert Service Bulletin A3364, Revision 3, dated May 29, 
1981.''

Conclusion

    We reviewed the relevant data, considered the comment received, and 
determined that air safety and the public interest require adopting 
this final rule with the change 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 addressing 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 the following service information.
     Boeing 707 Alert Service Bulletin A3364, Revision 4, dated 
February 21, 2017. This service information describes procedures for 
repetitive detailed inspections of the diagonal brace tube for any 
crack; repetitive detailed inspections and high frequency eddy current 
(HFEC) inspections of the nacelle strut diagonal brace end fittings, 
forward mating fitting, and aft mating

[[Page 48928]]

fitting for any crack; an alternative dye penetrant inspection of 
vertical webs on aft mating fitting for any crack; an HFEC inspection 
of the diagonal brace tube for any crack; and corrective actions.
     Boeing 707 Alert Service Bulletin A3365, Revision 3, dated 
March 9, 2017. This service information describes procedures for 
repetitive detailed, HFEC, and ultrasonic inspections of the overwing 
support fittings for any crack at the bolt hole forward of the wing 
front spar and at the holes for the four fasteners attaching the 
fitting to the spar, and related investigative and corrective actions.
     Boeing 707 Alert Service Bulletin A3514, Revision 1, dated 
November 9, 2016. This service information describes procedures for 
repetitive detailed and surface HFEC inspections of the front spar 
fittings at nacelle struts numbers 1, 2, 3, and 4 for cracks, and 
replacement of cracked front spar fittings.
    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 65 airplanes of U.S. registry. We 
estimate the following costs to comply with this AD:

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                Action                          Labor cost          Parts cost            Cost per product                  Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Detailed inspections per Service        36 work-hours x $85 per             $0  $3,060 per inspection cycle........  $198,900 per inspection cycle.
 Bulletin A3364, Revision 4.             hour = $3,060 per
                                         inspection cycle.
HFEC inspections per Service Bulletin   128 work-hours x $85 per             0  $10,880 per inspection cycle.......  $707,200 per inspection cycle.
 A3364, Revision 4.                      hour = $10,880 per
                                         inspection cycle.
Inspections per Service Bulletin        20 work-hours x $85 per              0  $1,700 per inspection cycle........  $110,500 per inspection cycle.
 A3365, Revision 3.                      hour = $1,700 per
                                         inspection cycle.
Detailed inspections per Service        12 work-hours x $85 per              0  $1,020 per inspection cycle........  $66,300 per inspection cycle.
 Bulletin A3514, Revision 1.             hour = $1,020 per
                                         inspection cycle.
HFEC inspections per Service Bulletin   32 work-hours x $85 per              0  $2,720 per inspection cycle........  $176,800 per inspection cycle.
 A3514, Revision 1.                      hour = $2,720 per
                                         inspection cycle.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    We estimate that any necessary replacement of affected fittings 
would take about 96 work-hours for a cost of $8,160 per fitting. We 
have received no definitive data on the parts costs of the affected 
fittings. We have no way of determining the number of aircraft that 
might need this replacement.
    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 and 
associated appliances 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):

2018-19-32 The Boeing Company: Amendment 39-19433; Docket No. FAA-
2018-0504; Product Identifier 2018-NM-046-AD.

(a) Effective Date

    This AD is effective November 2, 2018.

(b) Affected ADs

    This AD affects AD 82-24-03, Amendment 39-4496 (47 FR 51099, 
November 12, 1982) (``AD 82-24-03'') and AD 2005-08-15, Amendment 
39-14067 (70 FR 21136, April 25, 2005) (``AD 2005-08-15'').

(c) Applicability

    This AD applies to all The Boeing Company Model 707-100 Long 
Body, -200, -100B Long Body, and -100B Short Body series airplanes; 
Model 707-300, -300B, -300C, and -400 series airplanes; and Model 
720 and 720B series airplanes; certificated in any category.

(d) Subject

    Air Transport Association (ATA) of America Code 54, Nacelles/
pylons.

(e) Unsafe Condition

    This AD was prompted by a report indicating that a fracture of 
the midspar fitting resulted in the separation of the

[[Page 48929]]

inboard strut and engine from the airplane, and a determination that 
existing inspections for other nacelle strut fittings are not 
sufficient for timely detection of cracking. We are issuing this AD 
to address cracks, which if not detected and corrected, could grow 
beyond a critical length, allowing the strut fitting to fail and 
reducing the structural integrity of the nacelle. This, in 
combination with damage to adjacent attachment structure, could 
result in the loss of an engine from the airplane.

(f) Compliance

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

(g) Repetitive Detailed Inspections of the Front Spar Fittings at 
Nacelle Struts Numbers 1, 2, 3, and 4

    Prior to the accumulation of 3,500 total flight hours; within 
700 flight hours after the most recent inspection specified in 
Boeing 707 Alert Service Bulletin A3514, dated July 29, 2004, was 
done; or within three months after the effective date of this AD; 
whichever occurs later: Do a detailed inspection for cracking of the 
front spar fittings at nacelle struts numbers 1, 2, 3, and 4, in 
accordance with the Accomplishment Instructions of Boeing 707 Alert 
Service Bulletin A3514, Revision 1, dated November 9, 2016. If any 
cracking is found, before further flight, replace the affected 
fitting, in accordance with the Accomplishment Instructions of 
Boeing 707 Alert Service Bulletin A3514, Revision 1, dated November 
9, 2016. Repeat the inspections thereafter at intervals not to 
exceed 700 flight hours.

(h) Repetitive Surface High Frequency Eddy Current (HFEC) Inspections 
of the Aft Lugs on the Front Spar Fittings at Nacelle Struts Numbers 1, 
2, 3, and 4

    Within 1,500 flight cycles or 48 months after the most recent 
detailed inspection required by paragraph (g) of this AD was done, 
whichever occurs first, do a surface HFEC inspection for cracking of 
the aft lugs on the front spar fittings at nacelle struts numbers 1, 
2, 3, and 4, and do all applicable corrective actions, in accordance 
with the Accomplishment Instructions of Boeing 707 Alert Service 
Bulletin A3514, Revision 1, dated November 9, 2016, except as 
required by paragraph (l)(4) of this AD. Do all applicable 
corrective actions before further flight. Repeat the inspection 
thereafter at intervals not to exceed 1,500 flight cycles or 48 
months, whichever occurs first.

(i) Repetitive Inspections of the Overwing Support Fitting at Nacelle 
Struts Numbers 1, 2, 3, and 4

    At the times specified in paragraph 1.E., ``Compliance,'' of 
Boeing 707 Alert Service Bulletin A3365, Revision 3, dated March 9, 
2017, except as required by paragraph (l)(1) of this AD: Do the 
inspections specified in paragraphs (i)(1) through (i)(3) of this AD 
and do all applicable related investigative and corrective actions, 
in accordance with the Accomplishment Instructions of Boeing 707 
Alert Service Bulletin A3365, Revision 3, dated March 9, 2017, 
except as required by paragraph (l)(3) of this AD. Do all applicable 
related investigative and corrective actions before further flight. 
Repeat the inspections thereafter at the applicable time specified 
in paragraph 1.E., ``Compliance,'' of Boeing 707 Alert Service 
Bulletin A3365, Revision 3, dated March 9, 2017.
    (1) Do a detailed inspection for any crack at all five holes in 
the overwing support fitting, and at the flange radii.
    (2) Do the inspection specified in paragraph (i)(2)(i) or 
(i)(2)(ii) of this AD.
    (i) Do a surface HFEC inspection for any crack in the overwing 
support fitting around the hole immediately forward of the spar 
chord, with the bolt in place, and at the flange radii.
    (ii) Do an open hole HFEC inspection for any crack in the 
overwing support fitting at the hole immediately forward of the spar 
chord.
    (3) Do the inspection specified in paragraph (i)(3)(i) or 
(i)(3)(ii) of this AD.
    (i) Do an ultrasonic inspection for any crack in the overwing 
support fitting around the four holes common to the fitting and the 
spar chord, with the bolts in place.
    (ii) Do a surface HFEC inspection for any crack in the overwing 
support fitting around the four holes common to the fitting and the 
spar chord, with the bolts in place.

(j) Inspections of the Nacelle Strut Diagonal Braces and Associated 
Fittings

    For airplanes with nacelle strut diagonal braces and associated 
fittings which have accumulated 7,500 flight cycles or more: At the 
applicable times specified in paragraph 1.E., ``Compliance'' of 
Boeing 707 Alert Service Bulletin A3364, Revision 4, dated February 
21, 2017, except as required by paragraph (l)(2) of this AD, do the 
inspections specified in paragraphs (j)(1) through (j)(3) of this 
AD. Repeat the inspections thereafter at the applicable intervals 
specified in tables 1, 2, 3, and 4 of paragraph 1.E., 
``Compliance,'' of Boeing 707 Alert Service Bulletin A3364, Revision 
4, dated February 21, 2017. If any crack is found during any 
inspection required by this paragraph, before further flight, do all 
applicable corrective actions, in accordance with the Accomplishment 
Instructions of Boeing 707 Alert Service Bulletin A3364, Revision 4, 
dated February 21, 2017, except as required by paragraph (l)(3) of 
this AD.
    (1) Do a detailed inspection of the nacelle strut diagonal brace 
end fittings, diagonal brace tube, forward mating fitting, and aft 
mating fitting for any crack.
    (2) Do HFEC inspections of the nacelle strut diagonal brace end 
fittings, forward mating fitting, and aft mating fitting for any 
crack. As an alternative for the aft mating fitting, do a dye 
penetrant inspection of vertical webs on aft mating fitting for any 
crack.
    (3) Do an HFEC inspection of the diagonal brace tube for any 
crack.

(k) Replacement

    For Group 3, 4, and 6 airplanes as identified in Boeing 707 
Alert Service Bulletin A3364, Revision 4, dated February 21, 2017, 
on which the outboard diagonal brace end fitting (forward or aft) 
attach holes have been oversized as specified in Boeing 707 Alert 
Service Bulletin A3364, Revision 3, dated May 29, 1981: Within 1,000 
flight cycles after the effective date of this AD, replace the 
diagonal brace assembly, in accordance with Figure 3 of Boeing 707 
Alert Service Bulletin A3364, Revision 4, dated February 21, 2017.

(l) Exceptions to Service Information Specifications

    (1) For purposes of determining compliance with the requirements 
of this AD: Where Boeing 707 Alert Service Bulletin A3365, Revision 
3, dated March 9, 2017, uses the phrase ``the Revision 3 date of 
this service bulletin,'' this AD requires using ``the effective date 
of this AD.''
    (2) For purposes of determining compliance with the requirements 
of this AD: Where Boeing 707 Alert Service Bulletin A3364, Revision 
4, dated February 21, 2017, uses the phrase ``the Revision 4 date of 
this service bulletin,'' this AD requires using ``the effective date 
of this AD.''
    (3) Where Boeing 707 Alert Service Bulletin A3364, Revision 4, 
dated February 21, 2017; and Boeing 707 Alert Service Bulletin 
A3365, Revision 3, dated March 9, 2017; specify contacting Boeing: 
This AD requires repair using a method approved in accordance with 
the procedures specified in paragraph (o) of this AD.
    (4) Where Boeing 707 Alert Service Bulletin A3514, Revision 1, 
dated November 9, 2016, specifies contacting Boeing for replacement 
instructions: This AD requires replacement using a method approved 
in accordance with the procedures specified in paragraph (o) of this 
AD.

(m) Terminating Action for Other ADs

    (1) Accomplishing the initial inspections required by paragraph 
(j) of this AD terminates all requirements of AD 82-24-03.
    (2) Accomplishing the initial inspections required by paragraph 
(g) of this AD, terminates all requirements of AD 2005-08-15.

(n) Parts Installation Prohibition

    As of the effective date of this AD, no person may install, on 
any airplane, a front spar fitting having a part number other than 
the part numbers specified in paragraph 2.C.2. of Boeing 707 Alert 
Service Bulletin A3514, Revision 1, dated November 9, 2016.

(o) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles 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(s) identified in paragraph (p)(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.

[[Page 48930]]

    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, replacement, 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, Los Angeles ACO Branch, FAA, to make 
those findings. To be approved, the repair method, modification 
deviation, replacement deviation, or alteration deviation must meet 
the certification basis of the airplane, and the approval must 
specifically refer to this AD.

(p) Related Information

    (1) For more information about this AD, contact Jeffrey Chang, 
Aerospace Engineer, Propulsion Section, FAA, Los Angeles ACO Branch, 
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5263; fax: 562-627-5210; email: [email protected]; or George 
Garrido, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO 
Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 
562-627-5232; fax: 562-627-5210; email [email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (q)(3) and (q)(4) of this AD.

(q) 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 707 Alert Service Bulletin A3364, Revision 4, dated 
February 21, 2017.
    (ii) Boeing 707 Alert Service Bulletin A3365, Revision 3, dated 
March 9, 2017.
    (iii) Boeing 707 Alert Service Bulletin A3514, Revision 1, dated 
November 9, 2016.
    (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, 2200 South 216th St., Des Moines, WA. For 
information on the availability of this material at the FAA, call 
206-231-3195.
    (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 Des Moines, Washington, on September 17, 2018.
John P. Piccola,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2018-20918 Filed 9-27-18; 8:45 am]
BILLING CODE 4910-13-P