Document ID: FAA-2018-0142-0006
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: General Electric Company CF34-8E Engines
Posted Date: 2018-10-03T04:00Z

[Federal Register Volume 83, Number 192 (Wednesday, October 3, 2018)]
[Rules and Regulations]
[Pages 49784-49786]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-21378]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0142; Product Identifier 2018-NE-04-AD; Amendment 
39-19368; AD 2018-17-14]
RIN 2120-AA64

Airworthiness Directives; General Electric Company CF34-8E 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
General Electric Company (GE) CF34-8E turbofan engines. This AD was 
prompted by a report from GE regarding a quality escape of 
nonconforming thrust reverser fire seals. This AD requires 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 issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective November 7, 2018.

ADDRESSES: For service information identified in this final rule, 
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. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-
0142.

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 final rule, the regulatory evaluation, any comments received, and 
other information. The address for Docket Operations (phone: 800-647-
5527) 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: 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:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to certain GE CF34-8E turbofan 
engines. The NPRM published in the Federal Register on April 17, 2018 
(83 FR 16794). The NPRM was prompted by 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. The NPRM 
proposed to 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. We 
are issuing this AD to address the unsafe condition on these products.

Comments

    We gave the public the opportunity to participate in developing 
this final rule. The following presents the comments received on the 
NPRM and the FAA's response to each comment.

Request To Change the Applicability

    Two commenters, Horizon Air and Republic Airline, requested that we 
limit the applicability of this AD to a specific group of GE CF34-8E 
turbofan engine thrust reverser halves that are known to have a fire 
seal gap nonconformance. A change of applicability from all GE CF34-8E 
turbofan engines to only the known group of affected thrust reverser 
halves would reduce the inspection burden on operators.
    We agree. We changed the applicability of this AD to list only the 
affected half thrust reverser P/Ns and serial numbers. We also updated 
the number of affected thrust reverser assemblies and estimated costs.

Request To Change Required Actions

    Horizon Air requested that we change the required actions of this 
AD to replace ``all GE CF34-8E turbofan engines'' with ``all thrust 
reversers listed in paragraph (c).''
    We agree. We reworded the required actions of this AD to indicate 
that these actions are only required for GE CF34-

[[Page 49785]]

8E turbofan engines with affected half thrust reversers installed.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this final rule with the changes described previously and minor 
editorial changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM for addressing the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this final 
rule.

Related Service Information

    We reviewed GE CF34-8E Service Bulletin (SB) 78-0066 R01, dated 
June 20, 2018. 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.

Costs of Compliance

    We estimate that this AD affects 194 thrust reverser assemblies 
installed on airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspection............................  0.25 work-hours x $85                 $0          $21.25       $4,122.50
                                         per 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 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

    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) Is not a ``significant rule'' under 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.

Adoption of 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 (AD):

2018-17-14 General Electric Company: Amendment 39-19368 Docket No. 
FAA-2018-0142; Product Identifier 2018-NE-04-AD.

(a) Effective Date

    This AD is effective November 7, 2018.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE) CF34-8E 
turbofan engines with:
    (1) Left-hand (LH) half thrust reverser, part number (P/N) 
15G0002-013, or LH half thrust reverser P/N 15G0002-014, with the 
following serial numbers (S/Ns): HRD00659 to HRD00662, HRD00675 to 
HRD00678,

[[Page 49786]]

HRD00680, HRD00681, HRD00694 to HRD00697, HRD00711, HRD00831, 
HRD00856, HRD00878 to HRD00895, HRD01025, HRD01040, HRD01047, 
HRD01050 to HRD01057, HRD01059 to HRD01089, HRD01104, HRD01105, 
HRD01108, HRD01111 to HRD01116, HRD01118 to HRD01121, HRD01123, 
HRD01124, HRD01126, HRD01162, HRD01185 to HRD01198, HRD01201, 
HRD01202, or HRD01226 to HRD01243, installed.
    (2) Right-hand (RH) half thrust reverser, P/N 15G0003-013, or RH 
half thrust reverser P/N 15G0003-014, with the following S/Ns: 
HRD00669 to HRD00678, HRD00680, HRD00681, HRD00703 to HRD00707, 
HRD00722, HRD00825, HRD00919, HRD00922, HRD01018, HRD01022, 
HRD01023, HRD01027 to HRD01033, HRD01035, HRD01036, HRD01038, 
HRD01039, HRD01041 to HRD01046, HRD01048, HRD01049, HRD01059 to 
HRD01079, HRD01081, HRD01082, HRD01084 to HRD01092, HRD01100, 
HRD01117, HRD01140, HRD01146, HRD01162, HRD01185 to HRD01187, 
HRD01189 to HRD01198, HRD01201, HRD01202, HRD01210, or HRD01213 to 
HRD01223, installed.

(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 half thrust reversers listed in paragraph (c) of 
this AD, before the half thrust reverser 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: LH half thrust reverser, P/N 15G0002-013; LH half thrust 
reverser, P/N 15G0002-014; RH half thrust reverser, P/N 15G0003-013; 
and 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 returning to service.
    (2) You may refer to GE CF34-8E Service Bulletin 78-0066 R01, 
dated June 20, 2018, 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) of this AD. You may email your request 
to: [email protected].
    (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

    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].

(j) Material Incorporated by Reference

    None.

    Issued in Burlington, Massachusetts, on September 26, 2018.
Karen M. Grant,
Acting Manager, Engine and Propeller Standards Branch, Aircraft 
Certification Service.
[FR Doc. 2018-21378 Filed 10-2-18; 8:45 am]
 BILLING CODE 4910-13-P