[Federal Register Volume 82, Number 45 (Thursday, March 9, 2017)]
[Proposed Rules]
[Pages 13077-13079]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-04523]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9592; Directorate Identifier 2016-NE-30-AD]
RIN 2120-AA64


Airworthiness Directives; CFM International S.A. Turbofan 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 
certain CFM International S.A. (CFM) CFM56-3, -3B, and -3C turbofan 
engines. This proposed AD was prompted by a report of dual-engine loss 
of thrust control that resulted in an air turn back. This proposed AD 
would require initial and repetitive checks of the variable stator vane 
(VSV) actuation system in the high-pressure compressor (HPC). We are 
proposing this AD to correct the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by April 24, 2017.

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.
     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 CFM 
International Inc., Aviation Operations Center, 1 Neumann Way, M/D Room 
285, Cincinnati, OH 45125; phone: 877-432-3272; fax: 877-432-3329; 
email: [email protected]. You may view this service 
information at FAA, Engine & Propeller Directorate, 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-2016-
9592; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this proposed AD, the regulatory evaluation, any comments 
received, and other information. The street address for the Docket 
Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: David Bethka, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 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-2016-9592; 
Directorate Identifier 2016-NE-30-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this

[[Page 13078]]

proposed AD 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 proposed AD.

Discussion

    We received a report of a dual-engine loss of thrust control that 
resulted in an air turn back. Investigation determined that loss of 
thrust control was the result of restricted movement of the VSV 
actuation rings in the HPC stator case. This restricted movement 
resulted from resistance caused by corrosion in the VSV bores. This 
condition, if not corrected, could result in failure of the VSV 
actuators, loss of engine thrust control, and reduced control of the 
airplane.

Related Service Information

    We reviewed CFM Service Bulletin (SB) CFM56-3 S/B 72-1169, Revision 
01, dated April 25, 2016. This SB describes procedures for examining 
the VSV bores on the inside of the HPC case. We also reviewed CFM 
CFM56-3 Engine Shop Manual (ESM) 72-32-01, Repair 031, dated February 
8, 2016. This repair provides guidance on reaming and applying anti-
corrosion paint to the VSV bores.

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 initial and repetitive checks of 
stage 1, stage 2, and stage 3 of the HPC VSV actuation system.

Differences Between This Proposed AD and the Service Information

    CFM SB CFM56-3 S/B 72-1169, Revision 01, dated April 25, 2016, only 
recommends inspection of CFM56-3 engines if 50% or more of their 
operation occurs in tropical rainforest climate zones and the 
utilization rate is less than 150 hours per month. We find that 
corrosion could occur in other climate zones, and would be a function 
of hours as well as utilization. We also find it is not practical to 
base AD requirements on geography and, to a lesser extent, utilization. 
Therefore, we are proposing that this AD be applicable to all CFM56-3 
engines not previously repaired as described in CFM CFM56-3 ESM 72-32-
01, Repair 031, dated February 8, 2016. In addition, CFM SB CFM56-3 S/B 
72-1169 requires that repair be performed within 5 flight cycles if the 
pull force is measured to be greater than 100 lbs. Given that pull 
force greater than 100 lbs may result in loss of thrust control, we are 
proposing in this AD that repair be done prior to further flight.

Costs of Compliance

    We estimate that this proposed AD affects 460 engines installed on 
airplanes of U.S. registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
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                                                                                    Cost per       Cost on U.S.
              Action                        Labor cost            Parts cost        product         operators
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Inspection of the HPC VSV           2 work-hours x $85 per                 $0             $170          $78,200
 actuation system.                   hour = $170.
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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.

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 to the extent 
that it justifies making a regulatory distinction, 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):

CFM International S.A.: Docket No. FAA-2016-9592; Directorate 
Identifier 2016-NE-30-AD.

(a) Comments Due Date

    We must receive comments by April 24, 2017.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to CFM International S.A. (CFM) CFM56-3, -3B, 
and -3C turbofan engines.

[[Page 13079]]

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by a report of dual engine loss of thrust 
control that resulted in an air turn back. We are issuing this AD to 
prevent failure of the variable stator vane (VSV) actuators, loss of 
engine thrust control, and reduced control of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done. Within 12 months after the effective date of 
this AD:
    (1) Inspect the affected engines to determine if the compressor 
front stator case is marked with ``RP031'' adjacent to the part 
number. If the case is marked with ``RP031,'' no further action 
required. If the case is not marked with ``RP031,'' follow the 
remaining steps in paragraph (f) of this AD.
    (2) Perform an initial pull force check of stage 1, stage 2, and 
stage 3 of the compressor VSV actuation system.
    (i) If any stage requires more than 100 lbs force to move the 
actuation ring, ream the VSV bores and apply anti-corrosion coating 
to stage 1, 2, and 3, prior to further flight.
    (ii) If any stage requires more than 75 lbs and less than or 
equal to 100 lbs force to move the actuation ring, repeat the 
inspection within 3 months since last inspection.
    (iii) If all stages require 75 lbs force or less to move the 
actuation rings, repeat the inspection within 12 months since last 
inspection.
    (3) Thereafter, continue to perform repetitive pull force checks 
of stage 1, 2, and 3 of the compressor VSV actuation system and 
disposition as specified in paragraphs (2)(i) through (2)(iii) of 
this AD.

(g) Optional Terminating Action

    Reaming the VSV bores and applying anti-corrosion coating, as 
specified in paragraph (f)(2)(i) of this AD, is terminating action 
to the repetitive inspections required by paragraph (f)(3) of this 
AD.

(h) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
for this AD. Use the procedures found in 14 CFR 39.19 to make your 
request. You may email your request to: [email protected].

(i) Related Information

    (1) For more information about this AD, contact David Bethka, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; 
phone: 781-238-7129; fax: 781-238-7199; email: [email protected].
    (2) CFM Service Bulletin CFM56-3 S/B 72-1169, Revision 01, dated 
April 25, 2016, and CFM CFM56-3 Engine Shop Manual 72-32-01, Repair 
031, dated February 8, 2016, can be obtained from CFM using the 
contact information in paragraph (i)(3) of this proposed AD.
    (3) For service information identified in this AD, contact CFM 
International Inc., Aviation Operations Center, 1 Neumann Way, M/D 
Room 285, Cincinnati, OH 45125; phone: 877-432-3272; fax: 877-432-
3329; email: [email protected].
    (4) You may view this service information at the FAA, Engine & 
Propeller Directorate, 1200 District Avenue, Burlington, MA. For 
information on the availability of this material at the FAA, call 
781-238-7125.

    Issued in Burlington, Massachusetts, on February 28, 2017.
Carlos A. Pestana,
Acting Assistant Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2017-04523 Filed 3-8-17; 8:45 am]
BILLING CODE 4910-13-P