DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-1061; Project Identifier AD-2021-01192-E;
Amendment 39-21853; AD 2021-23-51]
RIN 2120-AA64

Airworthiness Directives; General Electric Company Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain General Electric Company (GE) CF34-8C and CF34-8E model
turbofan engines. This AD was prompted by an in-flight shutdown of an
engine and subsequent investigation by the manufacturer that revealed a
broken variable geometry (VG) actuator rod end caused by corrosion and
seizure of the rod end bearing. This AD requires performing an
inspection of the master compressor VG actuator and slave compressor VG
actuator and, depending on the results of the inspection, replacement
of the part with a part eligible for installation. This AD also
requires reporting the results of the inspection to GE. The FAA
previously sent an emergency AD to all known U.S. owners and operators
of these GE CF34-8C and CF34-8E model turbofan engines and is now
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective December 29, 2021. Emergency AD 2021-23-51,
issued on November 4, 2021, which contained the requirements of this
amendment, was effective with actual notice.
The Director of the Federal Register approved the incorporation by
reference of certain publications identified in this AD as of December
29, 2021.
The FAA must receive comments on this AD by January 28, 2022.

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 https://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 final rule, contact
General Electric Company, 1 Neumann Way, Cincinnati, OH 45215; phone:
(513) 552-3272; email: aviation.fleetsupport@ge.com; website: https://www.ge.com.
You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 1200
District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call (817) 222-5110. It is
also available at https://www.regulations.gov by searching for and
locating Docket No. FAA-2021-1061.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-1061; 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 street address for Docket
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Scott M. Stevenson, Aviation Safety
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803;
phone: (781) 238-7132; fax: (781) 238-7199; email:
scott.m.stevenson@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

On November 4, 2021, the FAA issued Emergency AD 2021-23-51 (the
emergency AD), which requires performing an inspection of the master
compressor VG actuator and slave compressor VG actuator and, depending
on the results of the inspection, replacement of the part with a part
eligible for installation. The emergency AD also requires reporting the
results of the inspection to GE. The FAA sent the emergency AD to all
known U.S. owners and operators of these engines. This action was
prompted by an event on August 11, 2021, in which a Bombardier CRJ1000
airplane, powered by GE CF34-8C5 model engines, experienced an in-
flight engine shutdown that resulted in a diversion. The manufacturer's
investigation found that these engines were parked outdoors for
extended lengths of time within 10 miles (16 km) from a saltwater
coastline. These conditions caused corrosion to develop on the
compressor VG actuator rod end bearing, which restricted the motion in
the bearing leading to an elevated stress in the rod end. Subsequently,
the higher stress cracked the rod end which eventually fractured. This
condition, if not addressed, could result in failure of one or more
engines, loss of engine thrust control, and reduced control of the
airplane.

FAA's Determination

The FAA is issuing 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.

Related Service Information Under 1 CFR Part 51

The FAA reviewed GE CF34-8C Service Bulletin (SB) 75-0028 R00 and
GE CF34-8E SB 75-0023 R00, both dated November 2, 2021. These SBs
specify procedures for performing a one-time inspection of the master
compressor VG actuator and slave compressor VG actuator, differentiated
by engine model, to identify possible rod end corrosion or seizure.
These SBs also instruct operators to report the inspection results to
GE. 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.

AD Requirements

This AD requires performing an inspection of the master compressor
VG actuator and slave compressor VG actuator and, depending on the
results of the inspection, replacement of the part with a part eligible
for installation. This AD also requires reporting the results of the
inspection to GE.

Interim Action

The FAA considers this AD to be an interim action. The FAA
anticipates that further AD action will follow.

Justification for Immediate Adoption and Determination of the Effective
Date

Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5
U.S.C. 551 et seq.) authorizes agencies to dispense with notice and
comment procedures for rules when the agency, for ``good cause,'' finds
that those procedures are ``impracticable,
unnecessary, or contrary to the public interest.'' Under this section,
an agency, upon finding good cause, may issue a final rule without
providing notice and seeking comment prior to issuance. Further,
section 553(d) of the APA authorizes agencies to make rules effective
in less than thirty days, upon a finding of good cause.
An unsafe condition exists that required the immediate adoption of
Emergency AD 2021-23-51, issued on November 4, 2021, to all known U.S.
owners and operators of these engines. The FAA found that the risk to
the flying public justified waiving notice and comment prior to
adoption of this rule. On August 11, 2021, a Bombardier CRJ1000
airplane, powered by GE CF34-8C5 model engines experienced an in-flight
engine shutdown caused by compressor VG actuator rod end failure due to
corrosion and seizure. This unsafe condition, caused by corrosion and
seizure of the compressor VG actuator rod end bearing, may result in
failure of one or more engines, loss of engine thrust control, and
reduced control of the airplane.
The FAA considers inspection of the compressor VG actuator rod end
bearings to be an urgent safety issue. Inspection of the compressor VG
actuator rod end bearings must be accomplished before accumulating 30
flight hours or within 5 calendar days on one engine installed on an
airplane. The other engine on the same airplane that has already had an
engine inspected must be inspected before accumulating 350 FHs or
within 60 calendar days. These conditions still exist, therefore,
notice and opportunity for prior public comment are impracticable and
contrary to the public interest pursuant to 5 U.S.C. 553(b)(3)(B).
In addition, the FAA finds that good cause exists pursuant to 5
U.S.C. 553(d) for making this amendment effective in less than 30 days,
for the same reasons the FAA found good cause to forego notice and
comment.

Comments Invited

The FAA invites you to send any written data, views, or arguments
about this final rule. Send your comments to an address listed under
ADDRESSES. Include ``Docket No. FAA-2021-1061; Project Identifier AD-
2021-01192-E'' at the beginning of your comments. The most helpful
comments reference a specific portion of the final rule, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this final rule because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
https://www.regulations.gov, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this final rule.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this AD contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this AD, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this AD. Submissions containing CBI should be sent to Scott
M. Stevenson, Aviation Safety Engineer, ECO Branch, FAA, 1200 District
Avenue, Burlington, MA 01803. Any commentary that the FAA receives
which is not specifically designated as CBI will be placed in the
public docket for this rulemaking.

Regulatory Flexibility Act

The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because FAA has determined
that it has good cause to adopt this rule without prior notice and
comment, RFA analysis is not required.

Costs of Compliance

The FAA estimates that this AD affects 2 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:

Estimated Costs

The FAA estimates the following costs to do any necessary
replacement that would be required based on the results of the
inspection. The agency has no way of determining the number of aircraft
that might need this replacement:

On-Condition Costs

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 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 currently 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 1 hour per response,
including the time for reviewing instructions, searching existing data
sources, gathering and maintaining the data needed, and completing and
reviewing the collection of information. All responses to this
collection of information are mandatory. Send comments regarding this
burden estimate or any other aspect of this collection of information,
including suggestions for reducing this burden to: Information
Collection Clearance Officer, Federal Aviation Administration, 10101
Hillwood Parkway, Fort Worth, TX 76177-1524.

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

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]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive: