AD 2018-23-51
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | Various | Airworthiness Directives; The Boeing Company Airplanes |
Unsafe Condition
If an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer.
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Required Actions
Revising certificate limitations and operating procedures of the airplane flight manual (AFM) to provide the flight crew with runaway horizontal stabilizer trim procedures to follow under certain conditions.
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Compliance Time
Before further flight
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Affected Aircraft
All The Boeing Company Model 737-8 and -9 airplanes, certificated in any category.
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Federal Register Abstract
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-8 and -9 airplanes. This emergency AD was sent previously to all known U.S. owners and operators of these airplanes. This AD requires revising certificate limitations and operating procedures of the airplane flight manual (AFM) to provide the flight crew with runaway horizontal stabilizer trim procedures to follow under certain conditions. This AD was prompted by analysis performed by the manufacturer showing that if an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer. We are issuing this AD to address the unsafe condition on these products.
Applicability Source Text
Show captured applicability text from the source AD
(c) Applicability
This AD applies to all The Boeing Company Model 737-8 and -9
airplanes, certificated in any category.
Document Text
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[Federal Register Volume 83, Number 237 (Tuesday, December 11, 2018)]
[Rules and Regulations]
[Pages 63561-63565]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: R1-2018-26365]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2018-0960; Product Identifier 2018-NM-151-AD; Amendment
39-19512; AD 2018-23-51]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
Editorial Note: Rule document 2018-26365 was originally
published on pages 62697 through 62700 in the issue of Thursday,
December 6, 2018. In that publication, on page 62700, in Figure 2 to
paragraph (h), the last sentence in the table was inadvertently
truncated. The corrected document is published here in its entirety.
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: We are adopting a new airworthiness directive (AD) for all The
Boeing Company Model 737-8 and -9 airplanes. This emergency AD was sent
previously to all known U.S. owners and operators of these airplanes.
This AD requires revising certificate limitations and operating
procedures of the airplane flight manual (AFM) to provide the flight
crew with runaway horizontal stabilizer trim procedures to follow under
certain conditions. This AD was prompted by analysis performed by the
manufacturer showing that if an erroneously high single angle of attack
(AOA) sensor input is received by the flight control system, there is a
potential for repeated nose-down trim commands of the horizontal
stabilizer. We are issuing this AD to address the unsafe condition on
these products.
DATES: This AD is effective December 21, 2018 to all persons except
those persons to whom it was made immediately effective by Emergency AD
2018-23-51, issued on November 7, 2018, which contained the
requirements of this amendment.
We must receive comments on this AD by January 22, 2019.
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: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
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> by searching for and locating Docket No. FAA-2018-
0960; 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 street address for
Docket Operations (phone: 800-647-5527) is in the ADDRESSES section.
Comments will be available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Douglas Tsuji, Senior Aerospace
Engineer, Systems and Equipment Section, FAA, Seattle ACO Branch, 2200
South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3548;
email: <a href="/cdn-cgi/l/email-protection#682c071d0f04091b463c1b1d0201280e0909460f071e"><span class="__cf_email__" data-cfemail="f6b29983919a9785d8a285839c9fb6909797d8919980">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Discussion
On November 7, 2018, we issued Emergency AD 2018-23-51, which
requires revising certificate limitations and operating procedures of
the AFM to provide the flight crew with runaway horizontal stabilizer
trim procedures to follow under certain conditions. This emergency AD
was sent previously to all known U.S. owners and operators of these
airplanes. This action was prompted by analysis performed by the
manufacturer showing that if an erroneously high single AOA sensor
input is received by the flight control system, there is a potential
for repeated nose-down trim commands of the horizontal stabilizer. This
condition, if not addressed, could cause the flight crew to have
difficulty controlling the airplane, and lead to excessive nose-down
attitude, significant altitude loss, and possible impact with terrain.
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 revising certificate limitations and operating
procedures of the AFM to provide the flight crew with runaway
horizontal stabilizer trim procedures to follow under certain
conditions.
[[Page 63562]]
Interim Action
We consider this AD interim action. If final action is later
identified, we might consider further rulemaking then.
FAA's Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of
Emergency AD 2018-23-51, issued on November 7, 2018, to all known U.S.
owners and operators of these airplanes. The FAA found that the risk to
the flying public justified waiving notice and comment prior to
adoption of this rule because an erroneously high single AOA sensor
input received by the flight control system can result in a potential
for repeated nose-down trim commands of the horizontal stabilizer,
which could cause the flight crew to have difficulty controlling the
airplane, and lead to excessive nose-down attitude, significant
altitude loss, and possible impact with terrain. These conditions still
exist and the AD is hereby published in the Federal Register as an
amendment to section 39.13 of the Federal Aviation Regulations (14 CFR
39.13) to make it effective to all persons.
Therefore, we find good cause that notice and opportunity for prior
public comment are impracticable. In addition, for the reason(s) stated
above, we find 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 final rule. Send your comments to an address
listed under the ADDRESSES section. Include the docket number FAA-2018-
0960 and Product Identifier 2018-NM-151-AD at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this final rule. We will
consider all comments received by the closing date and may amend this
final rule 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 final rule.
Costs of Compliance
We estimate that this AD affects 45 airplanes of U.S. registry. We
estimate the following costs to comply with this AD:
Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
Revising the AFM...................... 1 work-hour x $85 per $0 $85 $3,825
hour = $85.
----------------------------------------------------------------------------------------------------------------
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):
2018-23-51 The Boeing Company: Amendment 39-19512; Docket No. FAA-
2018-0960; Product Identifier 2018-NM-151-AD.
(a) Effective Date
This AD is effective December 21, 2018 to all persons except
those persons to whom it was made immediately effective by Emergency
AD 2018-23-51, issued on November 7, 2018, which contained the
requirements of this amendment.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 737-8 and -9
airplanes, certificated in any category.
(d) Subject
Air Transport Association (ATA) of America Code 27, Flight
controls.
[[Page 63563]]
(e) Unsafe Condition
This AD was prompted by analysis performed by the manufacturer
showing that if an erroneously high single angle of attack (AOA)
sensor input is received by the flight control system, there is a
potential for repeated nose-down trim commands of the horizontal
stabilizer. We are issuing this AD to address this potential
resulting nose-down trim, which could cause the flight crew to have
difficulty controlling the airplane, and lead to excessive nose-down
attitude, significant altitude loss, and possible impact with
terrain.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Revision of Airplane Flight Manual (AFM): Certificate Limitations
Within 3 days after the effective date of this AD, revise the
Certificate Limitations chapter of the applicable AFM to include the
information in figure 1 to paragraph (g) of this AD.
BILLING CODE 1301-00-D
[GRAPHIC] [TIFF OMITTED] TR11DE18.004
(h) AFM Revision: Operating Procedures
Within 3 days after the effective date of this AD, revise the
Operating Procedures chapter of the applicable AFM to include the
information in figure 2 to paragraph (h) of this AD.
[[Page 63564]]
[GRAPHIC] [TIFF OMITTED] TR11DE18.005
(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) of this AD. Information may be
emailed to: <a href="/cdn-cgi/l/email-protection#2a13076b646707794f4b5e5e464f076b6965076b67656907784f5b5f4f595e596a4c4b4b044d455c"><span class="__cf_email__" data-cfemail="380115797675156b5d594c4c545d15797b77157975777b156a5d494d5d4b4c4b785e5959165f574e">[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.
(j) Related Information
For more information about this AD, contact Douglas Tsuji,
Senior Aerospace Engineer, Systems and Equipment Section, FAA,
Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198;
phone and fax: 206-231-3548; email: <a href="/cdn-cgi/l/email-protection#65210a10020904164b3116100f0c250304044b020a13"><span class="__cf_email__" data-cfemail="c88ca7bdafa4a9bbe69cbbbda2a188aea9a9e6afa7be">[email protected]</span></a>.
(k) Material Incorporated by Reference
None.
[[Page 63565]]
Issued in Des Moines, Washington, on November 21, 2018.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification
Service.
[FR Doc. R1-2018-26365 Filed 12-7-18; 2:00 pm]
BILLING CODE 1301-00-C
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
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