Airworthiness Directives; CFM International, S.A., Turbofan Engines

[Federal Register Volume 85, Number 49 (Thursday, March 12, 2020)]
[Rules and Regulations]
[Pages 14413-14416]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-04997]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-1093; Project Identifier AD-2019-00144-E; 
Amendment 39-21103; AD 2020-06-01]
RIN 2120-AA64


Airworthiness Directives; CFM International, S.A., Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
CFM International S.A. (CFM) LEAP-1B21, -1B23, -1B25, -1B27, -1B28, -
1B28B1, -1B28B2, -1B28B2C, -1B28B3, -1B28BBJ1, and -1B28BBJ2 model 
turbofan engines. This AD was prompted by reports of two new unsafe 
conditions and the need to supersede corrective actions for two 
previously addressed unsafe conditions. This AD supersedes AD 2018-25-
09 and AD 2019-12-01, which apply to the affected LEAP-1B model 
turbofan engines. This AD requires revising the Airworthiness 
Limitations Section (ALS) of the applicable CFM LEAP-1B Engine Shop 
Manual and the operator's approved continuous airworthiness maintenance 
program. The FAA is issuing this AD to address the unsafe conditions on 
these products.

DATES: This AD is effective April 16, 2020.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of April 16, 
2020.

ADDRESSES: For service information identified in this final rule, 
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]">aviation.[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 https://www.regulations.gov by searching 
for

[[Page 14414]]

and locating Docket No. FAA-2019-1093.

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-
1093; 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, any comments received, and other information. The 
address for Docket Operations 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: Christopher McGuire, Aerospace 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: 781-238-7120; fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    The FAA published a Notice of Proposed Rulemaking (NPRM) in the 
Federal Register on January 23, 2020 (85 FR 3871), prompted by reports 
of two new unsafe conditions affecting CFM LEAP-1B model turbofan 
engines: (1) Increased fuel flow through certain fuel nozzles due to 
fuel nozzle coking, potentially causing distress to the static 
structures of the high-pressure turbine (HPT) and in-flight shutdown 
(IFSD) of one or more engines; and (2) the potential for undetected 
subsurface anomalies formed during the manufacturing process that could 
result in uncontained failure of the HPT stage 2 disk.
    The NPRM also resulted from additional information related to two 
unsafe conditions previously addressed by AD 2018-25-09, Amendment 39-
19520 (83 FR 63559, December 11, 2018) (``AD 2018-25-09''), and AD 
2019-12-01, Amendment 39-19656 (84 FR 28202, June 18, 2019) (``AD 2019-
12-01''), regarding: (1) Icing in the pressure sensor lines, 
potentially causing inaccurate pressure sensor readings and loss of 
thrust control; and (2) inadequate oil flow to the radial drive shaft 
(RDS) bearing, which can cause failure of the bearing and IFSD of one 
or more engines. AD 2018-25-09 applied to all CFM LEAP-1B21, -1B23, -
1B25, -1B27, -1B28, -1B28B1, -1B28B2, -1B28B2C, -1B28B3, -1B28BBJ1, and 
-1B28BBJ2 model turbofan engines. AD 2019-12-01 applied to CFM LEAP-
1B21, -1B23, -1B25, -1B27, -1B28, -1B28B1, -1B28B2, -1B28B3,-1B28B2C, -
1B28BBJ1, and -1B28BBJ2 model turbofan engines with certain RDS 
bearings installed. Thus, the FAA also proposed to supersede the two 
previously issued ADs addressing icing in the pressure sensor lines and 
inadequate oil flow to the RDS bearing.
    The NPRM proposed to require revising the ALS of the applicable CFM 
LEAP-1B Engine Shop Manual and the operator's approved continuous 
airworthiness maintenance program to: (1) Add an ultrasonic inspection 
of the HPT stage 2 disk to detect subsurface anomalies formed during 
manufacturing; (2) add an inspection of the RDS bearing to address 
inadequate oil flow to the RDS bearing; (3) require monitoring and 
inspections of the fuel nozzle to address the potential distress to HPT 
static structures due to nozzle coking; and (4) update the electronic 
engine control (EEC) system software to address potential for icing in 
the pressure sensor lines.
    The FAA is issuing this AD to address the unsafe conditions on 
these products.

Comments

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

Request To Use CFM Diagnostics for Engine Monitoring To Detect Fuel 
Nozzle Coking

    A commenter asked whether CFM Diagnostics reporting is an 
acceptable method of compliance for CFM Service Bulletin (SB) LEAP-1B-
73-00-0030-01A-930A-D, Issue 001, dated January 8, 2020 (``SB 73-
0030''). The commenter stated that CFM Diagnostics has created a 
diagnostic report that includes the limits published in SB 73-0030.
    The FAA agrees that use of CFM Diagnostics is an acceptable method 
of compliance for the engine monitoring in the ALS revisions required 
by this AD. This AD requires revising the ALS to include paragraph 
6.B.(1) of CFM Engine Shop Manual (ESM) Data Module LEAP-1B-05-29-00-
01A-281B-C, Issue 001, dated January 9, 2020 (``ESM 05-29''), which 
requires either engine monitoring or repetitive borescope inspections 
specified in SB 73-0030 to detect fuel nozzle coking. Given that SB 73-
0030 recommends the use of CFM Diagnostics to perform engine 
monitoring, no change to this AD is necessary.
    The commenter also asked whether switching between the engine 
monitoring and borescope inspection requirements is acceptable, because 
SB 73-0030 says that ``You must do the trend monitoring or BSI of the 
turbine hardware,'' which implies that only one of the two methods must 
be used. The commenter indicated that there may be scenarios when a 
data interruption occurs and they need to switch from engine condition 
monitoring to a borescope inspection.
    The FAA agrees that switching between the engine monitoring and 
borescope inspection requirements is acceptable because the FAA has 
previously approved SB 73-0030, which allows operators to use either 
option. Based on the foregoing, no change to this AD is necessary.

Request for Credit for Inspections of Transfer Gearbox (TGB) Related to 
Inadequate Oil Flow to RDS Bearing

    A commenter requested that the AD provide credit for inspections of 
the TGB performed in accordance with CFM SB LEAP-1B-72-00-0222-01A-
930A-D, Issue 007, dated May 17, 2019 (``SB 72-0222''). The commenter 
indicated that, although the service bulletins refer to different 
maintenance manual tasks, both SB 72-0222 and CFM SB LEAP-1B-72-00-
0317-01A-930A-D, Issue 001, dated January 9, 2020 (``SB 72-0317''), 
require inspections meeting the same criteria.
    The FAA agrees. This AD requires revising the ALS to include 
paragraph 6.B.(2) of ESM 05-29, which requires inspections of the RDS 
bearing as specified in SB 72-0317. SB 72-0317 provides the conditions 
for taking credit for inspections accomplished before the issuance of 
SB 72-0317, including inspections accomplished using SB 72-0222. 
Operators who meet the conditions specified in SB 72-0317 may take 
credit for previous inspections as part of their maintenance program. 
However, no change to this AD is necessary. Once an operator revises 
the ALS as required by this AD, the operator has fully complied with 
this AD. Compliance with the inspections remains mandatory as part of 
the ALS.

Support for the AD

    The Boeing Company and the Air Line Pilots Association expressed 
support for the AD as written.

No Comments on the AD

    United Airlines Engineering commented that it reviewed the NPRM and 
had no comments.

Conclusion

    The FAA reviewed the relevant data, considered the comments 
received, and determined that air safety and the

[[Page 14415]]

public interest require adopting this AD as proposed.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed CFM ESM Data Module LEAP-1B-05-21-03-01A-281B-C, 
Issue 002, dated January 9, 2020 (``ESM 05-21''); and ESM 05-29. ESM 
05-21 contains procedures for an ultrasonic inspection of the HPT stage 
2 disk. ESM 05-29 contains procedures for inspection of the RDS 
bearing, monitoring and inspections of the fuel nozzle, and the 
required version of EEC system software. 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.

Costs of Compliance

    The FAA estimates that this AD affects 162 engines installed on 
airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Update ALS............................  4 work-hours x $85 per                $0            $340         $55,080
                                         hour = $340.
TGB Screen Inspection.................  1 work-hour x 85 per                   0              85          13,770
                                         hour = 85.
HPT stage 2 Disk Inspection...........  6 work-hours x 85 per                  0             510          82,620
                                         hour = 510.
Fuel Nozzle Inspection................  6 work-hours x 85 per                  0             510          82,620
                                         hour = 510.
Pressure Sub-system Software Upgrade..  0.5 work-hours x 85 per                0           42.50           6,885
                                         hour = 42.50.
RDS Borescope Inspection..............  2 work-hours x 85 per                  0             170          27,540
                                         hour = 170.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
inspection. The FAA has no way of determining the number of aircraft 
that might need these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
RDS Replacement...............................  200 work-hours x $85 per hour =          $30,500         $47,500
                                                 $17,000.
HPT stage 2 Disk Replacement..................  1 work-hour x $85 per hour = $85         225,000         225,085
Replace Set of Fuel Nozzles...................  40 work-hours x $85 per hour =           120,000         123,400
                                                 $3,400.
----------------------------------------------------------------------------------------------------------------

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 rulemaking action.

Regulatory Findings

    The FAA has determined that 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) 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 
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:
0
a. Removing Airworthiness Directive (AD) 2018-25-09, Amendment 39-19520 
(FAA-2018-1023, December 11, 2018), and AD 2019-12-01, Amendment 39-
19656 (84 FR 28202, June 18, 2019); and
0
b. Adding the following new AD:

2020-06-01 CFM International, S.A.: Amendment 39-21103; Docket No. 
FAA-2019-1093; Project Identifier AD-2019-00144-E.

(a) Effective Date

    This AD is effective April 16, 2020.

(b) Affected ADs

    This AD replaces AD 2018-25-09, Amendment 39-19520 (83 FR 63559, 
December 11, 2018), and AD 2019-12-01, Amendment 39-19656 (84 FR 
28202, June 18, 2019).

(c) Applicability

    This AD applies to all CFM International S.A. (CFM) LEAP-1B21, -
1B23, -1B25, -1B27, -1B28, -1B28B1, -1B28B2, -1B28B3, -1B28B2C, -
1B28BBJ1, and -1B28BBJ2 model turbofan engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code, 7200 (Turbine/
Turboprop).

[[Page 14416]]

(e) Unsafe Condition

    (1) This AD was prompted by multiple reports of engine in-flight 
shutdowns (IFSDs) and defects in the related applicable systems and 
one report of a melt-related defect of the high-pressure turbine 
(HPT) stage 2 disk material. The FAA is issuing this AD to prevent:
    (i) Increased fuel flow through certain fuel nozzles leading to 
distress of the HPT static structures and IFSD of one or more 
engines;
    (ii) Undetected subsurface anomalies formed during the 
manufacturing process that could lead to uncontained HPT disk 
failure;
    (iii) Icing in the pressure sensor lines, inaccurate pressure 
sensor readings and loss of thrust control; and
    (iv) Inadequate oil flow to the radial drive shaft (RDS) 
bearing, failure of the bearing, and IFSD of one or more engines.
    (2) These unsafe conditions, if not addressed, could result in 
IFSD or failure of one or more engines, loss of thrust control and 
loss of the airplane.

(f) Compliance

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

(g) Required Actions

    Within 15 days after the effective date of this AD, revise the 
Airworthiness Limitations Section (ALS) of the applicable CFM LEAP-
1B Engine Shop Manual and the operator's existing approved 
continuous airworthiness maintenance program by inserting the 
following changes:
    (1) Paragraph 6.B.(2) of the CFM Engine Shop Manual (ESM) Data 
Module LEAP-1B-05-21-03-01A-281B-C, Issue 002, dated January 9, 
2020; and
    (2) Paragraphs 6.B.(1), 6.B.(2), and 6.C.(1) of the CFM ESM Data 
Module LEAP-1B-05-29-00-01A-281B-C, Issue 001, dated January 9, 
2020.

(h) No Alternative Procedures or Intervals

    After the revisions required by paragraph (g) of this AD have 
been made, no alternative inspections, procedures, or intervals may 
be used unless approved as an alternative method of compliance in 
accordance with the procedures specified in paragraph (i) of this 
AD.

(i) 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 (j) 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.

(j) Related Information

    For more information about this AD, contact Christopher McGuire, 
Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: 781-238-7120; fax: 781-238-7199; email: 
[email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) CFM International, S.A. (CFM) Engine Shop Manual (ESM) Data 
Module, LEAP-1B-05-21-03-01A-281B-C, Issue 002, dated January 9, 
2020; and
    (ii) CFM ESM Data Module LEAP-1B-05-29-00-01A-281B-C, Issue 001, 
dated January 9, 2020.
    (3) For CFM service information identified in this AD, contact 
CFM International, S.A., Aviation Operations Center, 1 Neumann Way, 
M/D Room 285, Cincinnati, OH 45125, United States; phone: (877) 432-
3272; email: [email protected].
    (4) You may view this service information at FAA, Engine & 
Propeller Standards Branch, 1200 District Avenue, Burlington, MA 
01803. For information on the availability of this material at the 
FAA, call 781-238-7759.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on March 5, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-04997 Filed 3-11-20; 8:45 am]
 BILLING CODE 4910-13-P

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