DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2019-0766; Product Identifier 2019-NE-23-AD]
Airworthiness Directives; General Electric Company Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for all General Electric Company (GE) CF34-8C1, CF34-8C5, CF34-8C5A1,
CF34-8C5B1, CF34-8C5A2, CF34-8C5A3, CF34-8E2, CF34-8E2A1, CF34-8E5,
CF34-8E5A1, CF34-8E5A2, CF34-8E6, and CF34-8E6A1 turbofan engine
models. This proposed AD was prompted by a predicted reduction in the
cyclic life of the combustion chamber assembly aft flange, which could
result in certain combustion chamber assemblies failing before reaching
their published life limit. This proposed AD would require revisions to
the Airworthiness Limitations Section (ALS) of the manufacturer's
Instructions for Continued Airworthiness (ICA) and to the air carrier's
approved Continued Airworthiness Maintenance Programs (CAMP) to
incorporate initial and repetitive fluorescent penetrant inspections
(FPIs) of the combustion chamber assembly. The FAA is proposing this AD
to address the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by January
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow
instructions for submitting comments.
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 NPRM, contact General
Electric Company, GE Aviation, Room 285, 1 Neumann Way, Cincinnati, OH
45215; phone: 513-552-3272; email: email@example.com. You
may view this service information at the FAA, Engine and Propeller
Standards Branch, 1200 District Avenue, Burlington, MA. For information
on the availability of this material at the FAA, call 781-238-7759.
Examining the AD Docket
You may examine the AD docket on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2019-
0766; 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 NPRM, the regulatory evaluation, any comments received, and other
information. The street address for Docket Operations is listed above.
Comments will be available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: David Bethka, Aerospace Engineer,
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-
238-7129; fax: 781-238-7199; email: firstname.lastname@example.org.
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2019-0766;
Product Identifier 2019-NE-23-AD" at the beginning of your comments.
The FAA specifically invites comments on the overall regulatory,
economic, environmental, and energy aspects of this NPRM. The FAA will
consider all comments received by the closing date and may amend this
NPRM because of those comments.
The FAA will post all comments received, without change, to https://www.
regulations.gov, including any personal information you provide.
The FAA will also post a report summarizing each substantive verbal
contact it receives about this NPRM.
The FAA was notified by the manufacturer that they found a
reduction in the cyclic life of the combustion chamber assembly when
updating their life analysis. As a result, the manufacturer added a
scheduled maintenance check. This condition, if not addressed, could
result in combustion chamber assemblies failing before reaching their
published life limit.
Related Service Information Under 1 CFR Part 51
The FAA reviewed GE CF34-8E Engine Manual Temporary Revision (TR)
05-0085, dated February 21, 2019; GE CF34-8C TR 05-0141, dated February
21, 2019; and GE CF34-8C TR 05-143, dated February 13, 2019. These TRs,
differentiated by GE CF34-8 turbofan engine model, identify the
combustion chamber assembly part number, life limit cycles, and new
The FAA also reviewed GE CF34-8E TR 05-0086, dated February 13,
2019, and GE CF34-8C TR 05-0142, dated February 13, 2019. These TRs,
differentiated by GE CF34-8 turbofan engine model, describe new
inspection threshold limits and re-inspection interval limits for the
combustion chamber assembly.
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.
The FAA is proposing this AD because it 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.
Proposed AD Requirements
This proposed AD would require revisions to the ALS of the
manufacturer's ICA and the air carrier's approved CAMP to incorporate
initial and repetitive FPIs of the combustion chamber assembly.
Costs of Compliance
The FAA estimates that this proposed AD affects 1,216 GE CF34-8C
turbofan engine models and 638 GE CF34-8E turbofan engine models
installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
|Revise the ALS and CAMP (GE CF34-8C
||1 work-hour x $85 per hour =
|FPI combustion chamber assembly
||6 work-hours x $85 per hour =
|FPI combustion chamber assembly
||5 work-hours x $85 per hour =
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
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 engines, propellers, and
associated appliances to the Manager, Engine and Propeller Standards
Branch, Policy and Innovation Division.
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed
(1) Is not a "significant regulatory action" under Executive
(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
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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