Rule2021-27957
Airworthiness Directives; The Boeing Company Airplanes
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
December 28, 2021
Effective
February 1, 2022
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-200 and -200C series airplanes. This AD was prompted by reports of nuisance stick shaker activation while the airplane was accelerating to cruise speed at the top of a climb. Investigation revealed that the activation was caused when the angle of attack (AOA) (also known as angle of airflow) sensor vanes froze and malfunctioned due to insufficient heat in certain AOA sensors to prevent ice buildup. This AD requires inspecting the AOA sensors for certain part numbers or vane shapes, and replacing any affected AOA sensor with a new or serviceable sensor. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 86 Issue 246 (Tuesday, December 28, 2021)</title>
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[Federal Register Volume 86, Number 246 (Tuesday, December 28, 2021)]
[Rules and Regulations]
[Pages 73670-73673]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-27957]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0543; Project Identifier AD-2021-00353-T;
Amendment 39-21852; AD 2021-25-09]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain The Boeing Company Model 737-200 and -200C series airplanes.
This AD was prompted by reports of nuisance stick shaker activation
while the airplane was accelerating to cruise speed at the top of a
climb. Investigation revealed that the activation was caused when the
angle of attack (AOA) (also
[[Page 73671]]
known as angle of airflow) sensor vanes froze and malfunctioned due to
insufficient heat in certain AOA sensors to prevent ice buildup. This
AD requires inspecting the AOA sensors for certain part numbers or vane
shapes, and replacing any affected AOA sensor with a new or serviceable
sensor. The FAA is issuing this AD to address the unsafe condition on
these products.
DATES: This AD is effective February 1, 2022.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of February 1,
2022.
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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>. You may view this service information at the
FAA, Airworthiness Products Section, Operational Safety 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 at
<a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and locating Docket No.
FAA-2021-0543.
Examining the AD Docket
You may examine the AD docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by
searching for and locating Docket No. FAA-2021-0543; 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, any
comments received, and other information. The address for Docket
Operations 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 W. Palmer, Aerospace Engineer,
Systems and Equipment Section, FAA, Los Angeles ACO Branch, 3960
Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5351;
email: <a href="/cdn-cgi/l/email-protection#93f9f6f5f5e1f6eabde4bde3f2fffef6e1d3f5f2f2bdf4fce5"><span class="__cf_email__" data-cfemail="87ede2e1e1f5e2fea9f0a9f7e6ebeae2f5c7e1e6e6a9e0e8f1">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain The Boeing
Company Model 737-200 and -200C series airplanes. The NPRM published in
the Federal Register on August 9, 2021 (86 FR 43454). The NPRM was
prompted by reports of nuisance stick shaker activation while the
airplane was accelerating to cruise speed at the top of a climb.
Investigation revealed that the activation was caused when the AOA
sensor vanes froze and malfunctioned due to insufficient heat in
certain AOA sensors to prevent ice buildup. In the NPRM, the FAA
proposed to require inspecting the AOA sensors for certain part numbers
or vane shapes, and replacing any affected AOA sensor with a new or
serviceable sensor. The FAA is issuing this AD to prevent the AOA
sensor vanes from being immobilized, which could result in unreliable
or inaccurate AOA sensor data being transmitted to airplane systems,
and consequent loss of control of the airplane.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from the Air Line Pilots Association,
International (ALPA) who supported the NPRM without change.
The FAA received an additional comment from Boeing. The following
presents the comment received on the NPRM and the FAA's response.
Request for Clarification of Affected Airplane Model
Boeing asked that clarification be added to the Summary,
Background, and Unsafe Condition sections of the proposed AD to specify
that the originating AOA vane immobilization report was not on a Model
737 airplane. Boeing stated that this would clarify the service history
and align the text with the language used in Boeing Alert Service
Bulletin 737-27A1324, dated March 2, 2021.
The FAA agrees to provide clarification, here in the comment
section instead of throughout the body of this AD. Initially, AOA vane
immobilization was reported on a Model 717 airplane; the associated
design issues have been addressed for that airplane model. Although no
Model 737-200 airplane has experienced an in-flight incident related to
the identified unsafe condition, the design of the AOA sensor vanes is
similar on Model 737-200 airplanes. Therefore, the FAA has determined
that this AD is necessary to address the unsafe condition on these
airplanes. The FAA has not changed this final rule as a result of this
comment.
Conclusion
The FAA reviewed the relevant data, considered any comments
received, and determined that air safety requires adopting this AD as
proposed. Except for minor editorial changes, and any other change
described previously, this AD is adopted as proposed in the NPRM. None
of the changes will increase the economic burden on any operator.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Alert Service Bulletin 737-27A1324, dated
March 2, 2021. This service information specifies procedures for doing
a general visual inspection of the left- and -right-side AOA sensor
vane shapes, or inspecting the left and right AOA sensors, to determine
the part number, and replacing any affected AOA sensor with a new or
serviceable sensor. 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 ADDRESSES.
Costs of Compliance
The FAA estimates that this AD will affect 11 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Inspection............................ 1 work-hour x $85 per $0 $85 $935
hour = $85.
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* * * * *
The FAA estimates the following costs to do any necessary
replacements that will be required based on the results of the
inspection. The agency has no way of determining the number of aircraft
that might need these replacements:
[[Page 73672]]
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
----------------------------------------------------------------------------------------------------------------
Replacement................................... 3 work-hours x $85 per hour = $54,000 $54,255
$255.
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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.
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) 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 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:
2021-25-09 The Boeing Company: Amendment 39-21852; Docket No. FAA-
2021-0543; Project Identifier AD-2021-00353-T.
(a) Effective Date
This airworthiness directive (AD) is effective February 1, 2022.
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 737-200 and -200C
series airplanes, certificated in any category, as identified in
Boeing Alert Service Bulletin 737-27A1324, dated March 2, 2021.
(d) Subject
Air Transport Association (ATA) of America Code 27, Flight
Control System.
(e) Unsafe Condition
This AD was prompted by reports of nuisance stick shaker
activation while the airplane was accelerating to cruise speed at
the top of a climb. Investigation revealed that the activation was
caused when the angle of attack (AOA) (also known as angle of
airflow) sensor vanes froze and malfunctioned due to insufficient
heat in certain AOA sensors to prevent ice buildup. The FAA is
issuing this AD to prevent the AOA sensor vanes from being
immobilized, which could result in unreliable or inaccurate AOA
sensor data being transmitted to airplane systems, and consequent
loss of control of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions for Group 2 Airplanes
For airplanes identified as Group 2 in Boeing Alert Service
Bulletin 737-27A1324, dated March 2, 2021: Within 120 days after the
effective date of this AD, inspect the AOA sensor, using a method
approved in accordance with the procedures specified in paragraph
(j) of this AD.
(h) Required Actions for Group 1 Airplanes
Except as specified in paragraph (i) of this AD: At the
applicable times specified in paragraph 1.E., ``Compliance,'' of
Boeing Alert Service Bulletin 737-27A1324, dated March 2, 2021, do
all applicable actions identified as ``RC'' (required for
compliance) in, and in accordance with, the Accomplishment
Instructions of Boeing Alert Service Bulletin 737-27A1324, dated
March 2, 2021.
(i) Exception to Service Information Specifications
Where Boeing Alert Service Bulletin 737-27A1324, dated March 2,
2021, uses the phrase ``the original issue date of this service
bulletin,'' this AD requires using ``the effective date of this
AD.''
(j) 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 identified in Related Information. Information may be
emailed to: <a href="/cdn-cgi/l/email-protection#ad9480ece3e080e1ececeee280ece0e2ee80ffc8dcd8c8ded9deedcbcccc83cac2db"><span class="__cf_email__" data-cfemail="cbf2e68a8586e6878a8a8884e68a868488e699aebabeaeb8bfb88badaaaae5aca4bd">[email protected]</span></a>.
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the responsible Flight Standards 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, Los
Angeles 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.
(4) For service information that contains steps that are labeled
as Required for Compliance (RC), the provisions of paragraphs
(j)(4)(i) and (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.
[[Page 73673]]
(k) Related Information
For more information about this AD, contact Jeffrey W. Palmer,
Aerospace Engineer, Systems and Equipment Section, FAA, Los Angeles
ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137;
phone: 562-627-5351; email: <a href="/cdn-cgi/l/email-protection#513b3437372334287f267f21303d3c3423113730307f363e27"><span class="__cf_email__" data-cfemail="abc1cecdcdd9ced285dc85dbcac7c6ced9ebcdcaca85ccc4dd">[email protected]</span></a>.
(l) 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 737-27A1324, dated March 2,
2021.
(ii) [Reserved]
(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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
(4) You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety 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, <a href="/cdn-cgi/l/email-protection#2c4a5e0245425f5c494f584543426c424d5e4d024b435a"><span class="__cf_email__" data-cfemail="fa9c88d49394898a9f998e939594ba949b889bd49d958c">[email protected]</span></a>, or go to: <a href="https://www.archives.gov/federal-register/cfr/ibr-locations.html">https://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
Issued on December 2, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2021-27957 Filed 12-27-21; 8:45 am]
BILLING CODE 4910-13-P
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