AD 2013-24-12
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | Various | Airworthiness Directives; The Boeing Company Airplanes |
Unsafe Condition
Cracking of the barrel nuts and bolts on each forward engine mount, which could result in reduced load capacity of the forward engine mount, and could result in separation of an engine under power from the airplane, and consequent loss of control of the airplane.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Conduct repetitive ultrasonic or dye penetrant inspections for cracking of the barrel nuts and bolts on each forward engine mount. Send inspection results and any cracked bolts and barrel nuts to the manufacturer. Take related investigative and corrective actions if necessary.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the compliance times specified in Boeing Alert Service Bulletin 747-71A2329.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
The Boeing Company Model 747-8 and 747-8F series airplanes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-8 and 747-8F series airplanes. This AD requires repetitive ultrasonic or dye penetrant inspections for cracking of the barrel nuts and bolts, as applicable, on each forward engine mount, and related investigative and corrective actions if necessary. This AD was prompted by a report of cracked barrel nuts found on a forward engine mount. We are issuing this AD to detect and correct cracked barrel nuts on a forward engine mount, which could result in reduced load capacity of the forward engine mount, and could result in separation of an engine under power from the airplane, and consequent loss of control of the airplane.
Applicability Source Text
Show captured applicability text from the source AD
(c) Applicability
This AD applies to all The Boeing Company Model 747-8 and 747-8F
series airplanes, certificated in any category.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 78, Number 231 (Monday, December 2, 2013)]
[Rules and Regulations]
[Pages 71989-71992]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2013-28616]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2013-0976; Directorate Identifier 2013-NM-198-AD;
Amendment 39-17686; AD 2013-24-12]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: We are adopting a new airworthiness directive (AD) for all The
Boeing Company Model 747-8 and 747-8F series airplanes. This AD
requires repetitive ultrasonic or dye penetrant inspections for
cracking of the barrel nuts and bolts, as applicable, on each forward
engine mount, and related investigative and corrective actions if
necessary. This AD was prompted by a report of cracked barrel nuts
found on a forward engine mount. We are issuing this AD to detect and
correct cracked barrel nuts on a forward engine mount, which could
result in reduced load capacity of the forward engine mount, and could
result in separation of an engine under power from the airplane, and
consequent loss of control of the airplane.
DATES: This AD is effective December 17, 2013.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 17,
2013.
We must receive comments on this AD by January 16, 2014.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://www.regulations.gov">http://www.regulations.gov</a>. Follow the instructions for submitting comments.
<bullet> Fax: 202-493-2251.
<bullet> 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.
<bullet> Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
For service information identified in this AD, contact Boeing
Commercial Airplanes, Attention: Data & Services Management, P. O. Box
3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000,
extension 1; fax 206-766-5680; Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
You may view this referenced service information at the FAA, Transport
Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. For
information on the availability of this material at the FAA, call 425-
227-1221.
Examining the AD Docket
You may examine the AD docket on the Internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a>; 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 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: Bill Ashforth, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: (425) 917-6432;
fax: (425) 917-6590; email: <a href="/cdn-cgi/l/email-protection#f89a919494d6998b909e978a8c90b89e9999d69f978e"><span class="__cf_email__" data-cfemail="e6848f8a8ac887958e808994928ea6808787c8818990">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
[[Page 71990]]
Discussion
We received a report that during the replacement of the No. 2
engine, an operator conducted a non-destructive test (NDT) inspection
of the barrel nuts on the forward engine mount and found cracks on two
of the four barrel nuts. The operator also discovered one cracked
barrel nut on the No. 1 engine. Boeing did a NDT on the No. 2 engine of
a flight test airplane and discovered two barrel nuts with cracks. The
barrel nuts are located at the forward end of the strut box and are
used to fasten the forward engine mount to the strut. A barrel nut with
a crack on one side is still able to carry ultimate load. A crack on
both sides of a barrel nut will cause complete failure of the barrel
nut. Complete failure of two or more barrel nuts on the same forward
engine mount reduces the load capacity of the forward engine mount and
could result in separation of an engine from the airplane. Cracked
barrel nuts on a forward engine mount, if not detected and corrected,
could result in reduced load capacity of the forward engine mount, and
could result in separation of an engine under power from the airplane,
and consequent loss of control of the airplane.
Relevant Service Information
We reviewed Boeing Alert Service Bulletin 747-71A2329, dated
September 27, 2013. For information on the procedures and compliance
times, see this service information at <a href="http://www.regulations.gov">http://www.regulations.gov</a> by
searching for Docket No. FAA-2013-0976.
FAA's Determination
We are issuing 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.
AD Requirements
This AD requires accomplishing the actions specified in the service
information described previously. This AD also requires sending the
inspection results and any cracked bolts and barrel nuts to the
manufacturer. The root cause of the cracking has not been determined
and inspection data from the fleet needs to be gathered and analyzed.
The FAA worked in conjunction with industry, under the
Airworthiness Directives Implementation Aviation Rulemaking Committee,
to enhance the AD system. One enhancement was a new process for
annotating which steps in the service information are required for
compliance with an AD. Differentiating these steps from other tasks in
the service information is expected to improve an owner's/operator's
understanding of crucial AD requirements and help provide consistent
judgment in AD compliance. The actions specified in the service
information described previously include steps that are labeled as
``RC'' (required for compliance) because these steps have a direct
effect on detecting, preventing, resolving, or eliminating an
identified unsafe condition.
As noted in the specified service information, steps labeled as
``RC'' must be done to comply with the AD. However, steps that are not
labeled as ``RC'' are recommended. Those steps that are not labeled as
``RC'' may be deviated from, done as part of other actions, or done
using accepted methods different from those identified in the service
information without obtaining approval of an alternative method of
compliance (AMOC), provided the steps labeled as ``RC'' can be done and
the airplane can be put back in a serviceable condition. Any
substitutions or changes to steps labeled as ``RC'' will require
approval of an AMOC.
The phrase ``related investigative actions'' is used in this AD.
``Related investigative actions'' are follow-on actions that (1) are
related to the primary actions, and (2) further investigate the nature
of any condition found. Related investigative actions in an AD could
include, for example, inspections.
In addition, the phrase ``corrective actions'' is used in this AD.
``Corrective actions'' are actions that correct or address any
condition found. Corrective actions in an AD could include, for
example, repairs.
Interim Action
This AD is considered to be interim action. The inspection reports
and return of cracked parts that are required by this AD will enable
the manufacturer to obtain better insight into the nature, cause, and
extent of the cracking, and eventually to develop final action to
address the unsafe condition. Once final action has been identified, we
might consider further rulemaking.
FAA's Justification and Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of
this AD. The FAA has found that the risk to the flying public justifies
waiving notice and comment prior to adoption of this rule because
cracked barrel nuts on a forward engine mount could result in reduced
load capacity of the forward engine mount, and could result in
separation of an engine under power from the airplane and consequent
loss of the control of the airplane. Therefore, we find that notice and
opportunity for prior public comment are impracticable and that good
cause exists for making this amendment effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements affecting flight
safety and was not preceded by notice and an opportunity for public
comment. However, we invite you to send any written data, views, or
arguments about this AD. Send your comments to an address listed under
the ADDRESSES section. Include the docket number FAA-2013-0976 and
Directorate Identifier 2013-NM-198-AD at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this AD. We will
consider all comments received by the closing date and may amend this
AD because of those comments.
We will post all comments we receive, without change, to <a href="http://www.regulations.gov">http://www.regulations.gov</a>, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this AD.
Costs of Compliance
We estimate that this AD affects 8 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
Inspections.................... Up to 24 work-hours x None............. Up to $2,040 per Up to $16,320 per
$85 per hour = $2,040 inspection cycle. inspection
per inspection cycle. cycle.
----------------------------------------------------------------------------------------------------------------
[[Page 71991]]
We estimate the following costs to do any necessary replacements
that would be required based on the results of the inspection. We have
no way of determining the number of aircraft that might need these
replacements:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product
----------------------------------------------------------------------------------------------------------------
Replacement of barrel nuts and 16 x $85 per hour = $1,360. Up to $480............ Up to $1,840.
bolts.
----------------------------------------------------------------------------------------------------------------
According to the manufacturer, some of the costs of this 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.
Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a current valid OMB control number. The control
number for the collection of information required by this AD is 2120-
0056. The paperwork cost associated with this AD has been detailed in
the Costs of Compliance section of this document and includes time for
reviewing instructions, as well as completing and reviewing the
collection of information. Therefore, all reporting associated with
this AD is mandatory. Comments concerning the accuracy of this burden
and suggestions for reducing the burden should be directed to the FAA
at 800 Independence Ave. SW., Washington, DC 20591. ATTN: Information
Collection Clearance Officer, AES-200.
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
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):
2013-24-12 The Boeing Company: Amendment 39-17686; Docket No. FAA-
2013-0976; Directorate Identifier 2013-NM-198-AD.
(a) Effective Date
This AD is effective December 17, 2013.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 747-8 and 747-8F
series airplanes, certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC)/Air Transport Association
(ATA) of America Code 71, Powerplant.
(e) Unsafe Condition
This AD was prompted by a report of cracked barrel nuts found on
a forward engine mount. We are issuing this AD to detect and correct
cracked barrel nuts on a forward engine mount, which could result in
reduced load capacity of the forward engine mount, and could result
in separation of an engine under power from the airplane, and
consequent loss of control of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Repetitive Inspections and Corrective Actions
Except as required by paragraph (h)(1) of this AD, at the time
specified in paragraph 1.E., ``Compliance,'' of Boeing Alert Service
Bulletin 747-71A2329, dated September 27, 2013: Do the inspection
specified in paragraph (g)(1) or (g)(2) of this AD, and do all
applicable related investigative and corrective actions, in
accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin 747-71A2329, dated September 27, 2013. Do all
applicable related investigative and corrective actions before
further flight. Repeat the inspection thereafter at the times
specified in paragraph 1.E., ``Compliance,'' of Boeing Alert Service
Bulletin 747-71A2329, dated September 27, 2013.
(1) Ultrasonic inspection for cracking of the barrel nuts on
each forward engine mount, except as required by paragraph (h)(2) of
this AD.
(2) Dye penetrant inspection for cracking of the bolts and
barrel nuts. Whenever a dye penetrant inspection is done, all the
bolts and barrel nuts on that engine mount must be removed and
replaced with new or serviceable parts.
(h) Exceptions to Service Information Specifications
(1) Where Boeing Alert Service Bulletin 747-71A2329, dated
September 27, 2013, 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.
[[Page 71992]]
(2) Where Appendix B of Boeing Alert Service Bulletin 747-
71A2329, dated September 27, 2013, states alternate instruments and
transducers can be used, this AD requires that only equivalent
instruments and transducers can be used.
(3) Where Appendix A of Boeing Alert Service Bulletin 747-
71A2329, dated September 27, 2013, states to record flight hours and
flight cycles, record the flight hours and flight cycles on the
airplane and the flight hours and flight cycles for each engine
since change or removal.
(i) Reporting and Sending Parts
After any inspection required by paragraph (g) of this AD:
Submit a report of the inspection results (both positive and
negative), and return all cracked bolts and barrel nuts, at the
applicable time specified in paragraph (i)(1) or (i)(2) of this AD.
The report must include the information requested in Appendix A of
Boeing Alert Service Bulletin 747-71A2329, dated September 27, 2013,
except as required by paragraph (h)(3) of this AD. Both the report
and all cracked bolts and barrel nuts must be sent to the address
specified in Appendix A of Boeing Alert Service Bulletin 747-
71A2329, dated September 27, 2013.
(1) For airplanes on which an ultrasonic inspection was done and
no cracking was found, do the required actions at the time specified
in paragraph (i)(1)(i) or (i)(1)(ii) of this AD, as applicable.
(i) If the inspection was done on or after the effective date of
this AD: Submit the report within 10 days after the inspection.
(ii) If the inspection was done before the effective date of
this AD: Submit the report within 10 days after the effective date
of this AD.
(2) For airplanes on which a dye penetrant inspection was done,
do the required actions at the time specified in paragraph (i)(2)(i)
or (i)(2)(ii) of this AD, as applicable.
(i) If the inspection was done on or after the effective date of
this AD: Submit the report and return all cracked bolts and barrel
nuts within 10 days after replacing the bolts and barrel nuts with
new or serviceable bolt and barrel nuts in accordance with Part 2 of
the Accomplishment Instructions of Boeing Alert Service Bulletin
747-71A2329, dated September 27, 2013.
(ii) If the inspection was done before the effective date of
this AD: Submit the report and return all cracked bolts and barrel
nuts within 10 days after the effective date of this AD.
(j) Paperwork Reduction Act Burden Statement
A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty
for failure to comply with a collection of information subject to
the requirements of the Paperwork Reduction Act unless that
collection of information displays a current valid OMB Control
Number. The OMB Control Number for this information collection is
2120-0056. Public reporting for this collection of information is
estimated to be approximately 5 minutes per response, including the
time for reviewing instructions, completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Comments concerning the accuracy of this
burden and suggestions for reducing the burden should be directed to
the FAA at: 800 Independence Ave. SW., Washington, DC 20591, Attn:
Information Collection Clearance Officer, AES-200.
(k) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Seattle Aircraft Certification Office (ACO),
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) of this AD.
Information may be emailed to: <a href="/cdn-cgi/l/email-protection#182135595655354b7d796c6c747d35595b57355955575b354a7d696d7d6b6c6b587e7979367f776e"><span class="__cf_email__" data-cfemail="21180c606f6c0c72444055554d440c60626e0c606c6e620c7344505444525552614740400f464e57">[email protected]</span></a>.
(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 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. For a repair method to be approved, the repair must
meet the certification basis of the airplane and the approval must
specifically refer to this AD.
(4) If the service information contains steps that are labeled
as ``RC'' (Required for Compliance), those steps must be done to
comply with this AD; any steps that are not labeled as ``RC'' are
recommended. Those steps that are not labeled as ``RC'' may be
deviated from, done as part of other actions, or done using accepted
methods different from those identified in the specified service
information without obtaining approval of an AMOC, provided the
steps labeled as ``RC'' can be done and the airplane can be put back
in a serviceable condition. Any substitutions or changes to steps
labeled as ``RC'' require approval of an AMOC.
(l) Related Information
For more information about this AD, contact Bill Ashforth,
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356;
phone: (425) 917-6432; fax: (425) 917-6590; email:
<a href="/cdn-cgi/l/email-protection#caa8a3a6a6e4abb9a2aca5b8bea28aacababe4ada5bc"><span class="__cf_email__" data-cfemail="77151e1b1b5916041f111805031f3711161659101801">[email protected]</span></a>.
(m) 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 747-71A2329, dated September
27, 2013.
(ii) Reserved.
(3) For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management,
P. O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
(4) You may view this service information at FAA, Transport
Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. 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: <a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
Issued in Renton, Washington, on November 19, 2013.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2013-28616 Filed 11-29-13; 8:45 am]
BILLING CODE 4910-13-P
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.