Document ID: FAA-2018-0142-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: General Electric Company CF34-8E Engines
Posted Date: 2018-04-17T04:00Z

[Federal Register Volume 83, Number 74 (Tuesday, April 17, 2018)]
[Proposed Rules]
[Pages 16794-16796]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-07819]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0142; Product Identifier 2018-NE-04-AD]
RIN 2120-AA64

Airworthiness Directives; General Electric Company CF34-8E 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
General Electric Company (GE) CF34-8E turbofan engines. This proposed 
AD was prompted by a report from GE regarding a quality escape of 
nonconforming thrust reverser fire seals. This proposed AD would 
require a one-time inspection of the gap between the core cowl seal and 
the pylon seal of the thrust reverser for correct gap width, and 
replacement of the seals, if needed. We are proposing this AD to 
address the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by June 1, 2018.

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 http://www.regulations.gov. Follow the instructions for submitting comments.

[[Page 16795]]

     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 NPRM, contact General 
Electric Company, 1 Neumann Way, Cincinnati, OH 45215; telephone 513-
552-3272; email [email protected]. You may view this service 
information at the FAA, Engine and Propeller Standards Branch, 1200 
District Avenue, Burlington, MA 01803. 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 http://www.regulations.gov by searching for and locating Docket No. FAA-2018-
0142; 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 (phone: 800-647-
5527) is listed above. Comments will be available in the AD docket 
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: David Bethka, Aerospace Engineer, ECO 
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-
238-7129; fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite 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-2018-0142; 
Product Identifier 2018-NE-04-AD'' at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this NPRM. We will consider all 
comments received by the closing date and may amend this NPRM because 
of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this NPRM.

Discussion

    We received a report from the manufacturer about a fire seal gap 
quality escape on GE CF34-8E turbofan engines. Some thrust reverser 
fire seals, installed on thrust reverser part numbers (P/Ns) 15G0002-
013, 15G0002-014, 15G0003-013, and 15G0003-014, were shipped from a 
supplier with nonconforming seal gaps.
    An analysis by the manufacturer has shown that a gap between the 12 
o'clock core cowl seal and pylon seal that is greater than the 1 mm 
design requirement could result in fire outside the fire zone. This 
unsafe condition, if not addressed, could result in an uncontrolled 
fire, damage to the engine, and damage to the airplane.

Related Service Information

    We reviewed GE CF34-8E Service Bulletin (SB) 78-0066 R00, dated 
December 11, 2017. The SB describes procedures for measuring the width 
of the RTV filled gap between the thrust reverser fire seals at the 12 
o'clock core cowl seal and pylon seal installed on thrust reverser P/Ns 
15G0002-013, 15G0002-014, 15G0003-013, and 15G0003-014, and replacing 
with parts eligible for installation, if needed.

FAA's Determination

    We are 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 require a one-time inspection of the gap 
between the core cowl seal and the pylon seal of the thrust reverser 
for correct gap width, and replacement of the thrust reverser fire 
seals, if needed.

Costs of Compliance

    We estimate that this proposed AD affects 936 engines installed on 
airplanes of U.S. registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
               Action                         Labor cost            Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspection.........................  0.25 work-hours x $85 per                $0          $21.25         $19,890
                                      hour = $21.25.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed inspection. 
We have no way of determining the number of aircraft that might need 
these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                   Action                                 Labor cost                Parts cost        product
----------------------------------------------------------------------------------------------------------------
Remove and replace thrust reverser fire      2.75 work-hours x $85 per hour =             $3,228       $3,461.75
 seals.                                       $233.75.
----------------------------------------------------------------------------------------------------------------

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

[[Page 16796]]

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 engines, propellers, and 
associated appliances to the Manager, Engine and Propeller Standards 
Branch, Policy and Innovation Division.

Regulatory Findings

    We 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 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the 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.

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

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):

General Electric Company: Docket No. FAA-2018-0142; Product 
Identifier 2018-NE-04-AD.

(a) Comments Due Date

    We must receive comments by June 1, 2018.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all General Electric Company (GE) CF34-8E 
turbofan engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7830, Thrust 
Reverser.

(e) Unsafe Condition

    This AD was prompted by a report from GE regarding a quality 
escape of nonconforming thrust reverser fire seal gaps. We are 
issuing this AD to inspect for nonconforming thrust reverser fire 
seal gaps that could result in a fire outside the fire zone. The 
unsafe condition, if not addressed, could result in an uncontrolled 
fire, damage to the engine, and damage to the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) For all CF34-8E turbofan engines, before the engine 
accumulates 8,000 flight hours after the effective date of this AD, 
perform the following one-time inspection, and, if needed, replace 
the core cowl seal and pylon seal.
    (i) Measure the width of the RTV filled gap between thrust 
reverser fire seals at the junction between 12 o'clock core cowl 
seal and pylon seal, at the following half thrust reverser 
locations: engine 1 left hand (LH) half thrust reverser, part number 
(P/N) 15G0002-013; engine 2 LH half thrust reverser, P/N 15G0002-
014; engine 1 right hand (RH) half thrust reverser, P/N 15G0003-013; 
and engine 2 RH half thrust reverser P/N 15G0003-014.
    (ii) If the gap width between the 12 o'clock core cowl seal and 
the pylon seal is greater than 1 mm, replace both seals with parts 
eligible for installation to form a new gap of 1 mm or less, prior 
to return to service.
    (2) You may refer to GE CF34-8E Service Bulletin 78-0066 R00, 
dated December 11, 2017 for guidance on inspecting and replacing the 
thrust reverser fire seals.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO 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 (i)(1) of this AD.
    (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.

(i) Related Information

    (1) For more information about this AD, contact David Bethka, 
Aerospace Engineer, ECO Branch, FAA,1200 District Avenue, 
Burlington, MA 01803; phone: 781-238-7129; fax: 781-238-7199; email: 
[email protected].
    (2) For service information identified in this AD, contact 
General Electric Company, 1 Neumann Way, Cincinnati, OH 45215; 
telephone 513-552-3272; email [email protected]. You may 
view this referenced service information at the FAA, Engine and 
Propeller Standards Branch, 1200 District Avenue, Burlington, MA 
01803. For information on the availability of this material at the 
FAA, call 781-238-7759.

    Issued in Burlington, Massachusetts, on April 9, 2018.
Robert J. Ganley,
Manager, Engine and Propeller Standards Branch, Aircraft Certification 
Service.
[FR Doc. 2018-07819 Filed 4-16-18; 8:45 am]
 BILLING CODE 4910-13-P