80 FR 59672 - Airworthiness Directives; CFM International S.A. Turbofan Engines

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 80, Issue 191 (October 2, 2015)

We propose to adopt a new airworthiness directive (AD) for certain CFM International S.A. (CFM) CFM56-5B series turbofan engines. This proposed AD was prompted by a corrected lifing analysis by the engine manufacturer that shows the need to identify an initial and repetitive inspection threshold for certain part number (P/N) turbine rear frames (TRFs). This proposed AD would require initial and repetitive inspections of certain P/N TRFs on the low-pressure turbine (LPT) frame assembly. We are proposing this AD to prevent failure of the TRF on the LPT frame assembly, which could lead to engine separation, damage to the engine, and damage to the airplane.

[Federal Register Volume 80, Number 191 (Friday, October 2, 2015)]
[Proposed Rules]
[Pages 59672-59674]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-24729]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-2983; Directorate Identifier 2015-NE-20-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) CFM56-5B series turbofan engines. 
This proposed AD was prompted by a corrected lifing analysis by the 
engine manufacturer that shows the need to identify an initial and 
repetitive inspection threshold for certain part number (P/N) turbine 
rear frames (TRFs). This proposed AD would require initial and 
repetitive inspections of certain P/N TRFs on the low-pressure turbine 
(LPT) frame assembly. We are proposing this AD to prevent failure of 
the TRF on the LPT frame assembly, which could lead to engine 
separation, damage to the engine, and damage to the airplane.

DATES: We must receive comments on this proposed AD by December 1, 
2015.

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.

[[Page 59673]]

     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 proposed 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]. You may view this service 
information at the FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, 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-2015-
2983; 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: Kyle Gustafson, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; phone: 781-238-7183; 
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-2015-2983; 
Directorate Identifier 2015-NE-20-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 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 were informed by CFM that it has corrected its lifing analysis 
for the TRF, P/N 338-102-907-0 and P/N 338-102-908-0, on the LPT frame 
assembly installed on CFM56-5B turbofan engines. This corrected lifing 
analysis shows the need for initial and repetitive inspections of 
certain P/N TRFs to manage low-cycle fatigue cracks. This condition, if 
not corrected, could result in failure of the TRF on the LPT frame 
assembly, which could lead to engine separation, damage to the engine, 
and damage to the airplane.
    The initial and repetitive inspection intervals differ depending on 
whether CFM Service Bulletin (SB) No. CFM56-5B S/B 72-0308, Revision 5, 
dated October 12, 2007, has been applied. We are proposing to allow 
engines with TRFs that have exceeded the initial inspection threshold a 
continued in-service allowance of 150 cycles to provide sufficient time 
to perform the initial inspection. The proposed repetitive inspection 
intervals are based on the size of the crack, if any, found during the 
inspection.

Relevant Service Information Under 1 CFR Part 51

    We reviewed CFM SB No. CFM56-5B S/B 72-0850, dated December 19, 
2012, and CFM SB No. CFM56-5B S/B 72-0308, Revision 5, dated October 
12, 2007. CFM SB No. CFM56-5B S/B 72-0850 describes procedures for 
inspecting the TRF. CFM SB No. CFM56-5B S/B 72-0308 identifies the 
engines to which this proposed AD applies. 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 of this document.

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 inspections 
of the TRF on the LPT frame assembly.

Costs of Compliance

    We estimate that this proposed AD would affect about 94 engines 
installed on airplanes of U.S. registry. We also estimate that it would 
take about 3 hours per engine to do the inspection. The average labor 
rate is $85 per hour. Based on these figures, we estimate the cost of 
this proposed AD on U.S. operators to be $23,970.

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:

[[Page 59674]]

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-2015-2983; Directorate 
Identifier 2015-NE-20-AD.

(a) Comments Due Date

    We must receive comments by December 1, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to CFM International S.A. (CFM) CFM56-5B engines 
with turbine rear frame (TRF), part number (P/N) 338-102-907-0 or P/
N 338-102-908-0, installed.

(d) Unsafe Condition

    This AD was prompted by a corrected lifing analysis by the 
engine manufacturer that shows the need for an initial and 
repetitive inspection of certain P/N TRFs on the low-pressure 
turbine (LPT) frame assembly. We are issuing this AD to prevent 
failure of the TRF on the LPT frame assembly, which could lead to 
engine separation, damage to the engine, and damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) For Engines that have Applied CFM Service Bulletin (SB) No. 
CFM56-5B S/B 72-0308:
    (i) Prior to accumulating 25,000 cycles since new (CSN) on the 
TRF of the LPT frame assembly or within 150 cycles after the 
effective date of this AD, whichever occurs later, perform an 
initial eddy current inspection (ECI) or a fluorescent penetrant 
inspection (FPI) of the TRF mount struts on the LPT assembly.
    (ii) For engines with unknown CSN on the TRF of the LPT frame 
assembly, perform the initial inspection required by this AD within 
150 cycles-in-service after the effective date of this AD.
    (iii) Use paragraph 3.B. in the Accomplishment Instructions of 
CFM SB No. CFM56-5B S/B 72-0850, dated December 19, 2012, to do the 
ECI and paragraph 3.C. in the Accomplishment Instructions of CFM SB 
No. CFM56-5B S/B 72-0850, to do the FPI. Do not include TRF mount 
strut crack lengths towards the cumulative crack length after the 
cracks are repaired.
    (iv) If no cracks are found on any of the three TRF mount 
struts, or the cumulative length of all cracks at any TRF mount 
strut location is less than 0.20 inches, repeat the inspection 
within 1,670 cycles since last inspection (CSLI).
    (v) If the cumulative length of cracks at any TRF mount strut 
location is greater than or equal to 0.20 inches, but less than 0.25 
inches, repeat the inspection within 280 CSLI.
    (vi) If the cumulative length of cracks at any TRF mount strut 
location is 0.25 inches or greater, replace the TRF with a part 
eligible for installation before further flight.
    (2) For Engines that have Not Applied CFM SB No. CFM56-5B S/B 
72-0308:
    (i) Prior to accumulating 32,000 CSN on the TRF of the LPT frame 
assembly or within 150 cycles after the effective date of this AD, 
whichever occurs later, perform an initial ECI or FPI of the TRF 
mount struts on the LPT frame assembly.
    (ii) For engines with unknown CSN on the TRF of the LPT frame 
assembly, perform the initial inspection required by this AD within 
150 cycles-in-service after the effective date of this AD.
    (iii) Use paragraph 3.B. in the Accomplishment Instructions of 
CFM SB No. CFM56-5B S/B 72-0850, dated December 19, 2012, to do the 
ECI and paragraph 3.C. in the Accomplishment Instructions of CFM SB 
No. CFM56-5B S/B 72-0850, to do the FPI. Do not include TRF mount 
strut crack lengths towards the cumulative crack length after the 
cracks are repaired.
    (iv) If no cracks are found on any of the three TRF mount 
struts, or the cumulative length of cracks at any TRF mount strut 
location is less than 0.20 inches, repeat the inspection within 
2,500 CSLI.
    (v) If the cumulative length of cracks at any TRF mount strut 
location is greater than or equal to 0.20 inches and less than 0.25 
inches, repeat the inspection within 370 CSLI.
    (vi) If the cumulative length of cracks at any TRF mount strut 
location is 0.25 inches or greater, replace the TRF with a part 
eligible for installation before further flight.

(f) 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].

(g) Related Information

    (1) For more information about this AD, contact Kyle Gustafson, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: 781-238-7183; fax: 781-238-7199; email: 
[email protected].
    (2) CFM SB No. CFM56-5B S/B 72-0850, dated December 19, 2012, 
and CFM SB No. CFM56-5B S/B 72-0308, Revision 5, dated October 12, 
2007, can be obtained from CFM using the contact information in 
paragraph (g)(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, 12 New England Executive Park, Burlington, 
MA. For information on the availability of this material at the FAA, 
call 781-238-7125.

    Issued in Burlington, Massachusetts, on September 24, 2015.
Colleen M. D'Allesandro,
Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-24729 Filed 10-1-15; 8:45 am]
 BILLING CODE 4910-13-P