DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2019-0394; Product Identifier 2017-NE-36-AD]
Airworthiness Directives; General Electric Company Turbofan
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to supersede Airworthiness Directive
2017-23-06, which applies to certain General Electric Company (GE)
CF34-8C1, CF34-8C5, CF34-8C5A1, and CF34-8C5B1 engines. AD 2017-23-06
requires an inspection of the bleed air manifold link rod assemblies
and the supply, return, and drain fuel fittings on the operability
bleed valve (OBV). Since the FAA issued AD 2017-23-06, the manufacturer
developed improved inspection techniques and determined these
inspections should be applied to additional engine models. This
proposed AD would require repetitive inspections of the OBV fuel tubes,
OBV bleed air manifold link rod assemblies, and the OBV fuel fittings
and replacement of OBVs or related hardware that fail inspection. The
FAA is proposing this AD to address the unsafe condition on these
DATES: The FAA must receive comments on this proposed AD by August
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 http://www.regulations.gov. Follow the
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; fax: 513-552-3329; 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 781-238-7125.
Examining the AD Docket
You may examine the AD docket on the internet at http://www.regulations.
gov by searching for and locating Docket No. FAA-2019-0394;
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: Michael Richardson-Bach, Aerospace
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803;
phone: 781-238-7747; fax: 781-238-7199; email: michael.richardson-bach@
The FAA invites you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include "Docket No. FAA-2019-0394;
Product Identifier 2017-NE-36-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, without change, to http://www.regulations.
gov, including any personal information you provide.
The FAA will also post a report summarizing each substantive verbal
contact we receive about this proposed AD.
The FAA issued AD 2017-23-06, Amendment 39-19100 (82 FR 52830,
November 15, 2017), ("AD 2017-23-06"), for certain General Electric
Company (GE) CF34-8C1, CF34-8C5, CF34-8C5A1, and CF34-8C5B1 engines. AD
2017-23-06 requires an inspection of the bleed air manifold link rod
assemblies and the supply, return, and drain fuel fittings on the OBV.
AD 2017-23-06 resulted from reports that significant fuel leaks, some
resulting in engine fires, occurred on multiple occasions due to
malfunctions related to the OBVs. The FAA issued AD 2017-23-06 to
address the unsafe condition on these products.
Actions Since AD 2017-23-06 Was Issued
Since the FAA issued AD 2017-23-06, the manufacturer has developed
improved inspections of the OBV bleed air manifold link rod assemblies
and OBV fuel fittings, added an inspection of the OBV fuel tubes, and
determined that these inspections should be applied to additional
engine models. GE published these improved inspections in GE Service
Bulletin (SB) CF34-8C-AL S/B 75-0020, R04, dated May 10, 2019.
Related Service Information Under 1 CFR Part 51
The FAA reviewed GE SB CF34-8C-AL S/B 75-0020, R04, dated May 10,
2019. The SB describes procedures for inspecting the bleed air manifold
link rod assemblies; the supply, return, and drain fuel fittings; and
the fuel tubes on the OBV. 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
The FAA is proposing 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.
Proposed AD Requirements
This proposed AD would retain all the requirements of AD 2017-23-06.
This proposed AD would revise the inspections of the OBV bleed air
manifold link rod assemblies and OBV fuel fittings and require
inspections of the OBV fuel tubes. In addition, this proposed AD would
expand the applicability of these inspections to include additional GE
CF34-8C model turbofan engines.
The FAA considers this proposed AD interim action. The FAA will
consider further rulemaking based on the continued investigation and
development of corrective action by the manufacturer.
Costs of Compliance
The FAA estimates that this proposed AD affects 1,297 engines installed
on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed AD:
|Inspection of OBV fuel tubes,
assemblies, and fittings.
||1 work-hour x $85 per hour =
The FAA estimates the following costs
to do any necessary
replacements that would be required based on the results of the
proposed inspection. The FAA has no way of determining the number of
aircraft that might need these replacements:
||2 work-hours x $85 per hour =
|Replace OBV support hardware
||2.25 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 has 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
For the reasons discussed above, I certify that the 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 removing Airworthiness Directive (AD)
2017-23-06, Amendment 39-19100 (82 FR 52830, November 15, 2017), and
adding the following new AD: