80 FR 32440 - Special Conditions: CFM International, LEAP-1A and -1C Engine Models; Incorporation of Woven Composite Fan Blades

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 80, Issue 110 (June 9, 2015)

Page Range		32440-32441
FR Document		2015-14084

These special conditions are issued for the CFM International (CFM), LEAP-1A and -1C engine models. These engine models will have a novel or unusual design feature associated with the engine fan blades-- new woven composite fan blades. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

Federal Register, Volume 80 Issue 110 (Tuesday, June 9, 2015)

[Federal Register Volume 80, Number 110 (Tuesday, June 9, 2015)]
[Rules and Regulations]
[Pages 32440-32441]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-14084]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 33

[Docket No. FAA-2014-0637; Special Conditions No. 33-015-SC]


Special Conditions: CFM International, LEAP-1A and -1C Engine 
Models; Incorporation of Woven Composite Fan Blades

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

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

SUMMARY: These special conditions are issued for the CFM International 
(CFM), LEAP-1A and -1C engine models. These engine models will have a 
novel or unusual design feature associated with the engine fan blades--
new woven composite fan blades. The applicable airworthiness 
regulations do not contain adequate or appropriate safety standards for 
this design feature. These special conditions contain the additional 
safety standards that the Administrator considers necessary to 
establish a level of safety equivalent to that established by the 
existing airworthiness standards.

DATES: Effective July 9, 2015.

FOR FURTHER INFORMATION CONTACT: For technical questions concerning 
this action, contact Alan Strom, ANE-111, Engine and Propeller 
Directorate, Aircraft Certification Service, 12 New England Executive 
Park, Burlington, Massachusetts 01803; telephone (781) 238-7143; 
facsimile (781) 238-7199; email alan.strom@faa.gov.
    For legal questions concerning this action, contact Vincent 
Bennett, ANE-7, Engine and Propeller Directorate, Aircraft 
Certification Service, 12 New England Executive Park, Burlington, 
Massachusetts 01803; telephone (781) 238-7044; facsimile (781) 238-
7055; email vincent.bennett@faa.gov.

SUPPLEMENTARY INFORMATION: 

Background

    On June 27, 2012, CFM International (CFM) applied for a type 
certificate for their new LEAP-1A and -1C engine models. The LEAP 
engine models are high-bypass-ratio engines that incorporate a novel 
and unusual design feature--new woven composite fan blades. The woven 
composite fan blades will have significant differences in material 
property characteristics when compared to conventionally designed fan 
blades using non-composite metallic materials.
    Special conditions are required to ensure that the LEAP-1A and -1C 
woven composite design fan blades account for the differences in 
material properties and failure modes relative to conventional single-
load path metallic blades. In addition, different containment 
requirements may be applied provided CFM shows that the blade design 
below the inner annulus flow path line provides multiple load paths and 
crack arresting features that prevent delamination or crack propagation 
to blade failure during the life of the blade.
    These special conditions are necessary because the applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for the new woven composite design fan blades.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, CFM must show that the LEAP-1A and -1C engine models meet 
the applicable provisions of the applicable regulations in effect on 
the date of application, except as detailed in paragraphs 21.101(b) and 
(c). The FAA has determined the following certification basis for the 
LEAP-1A and -1C engine models:
    1. 14 CFR part 33, ``Airworthiness Standards: Aircraft Engines,'' 
dated February 1, 1965, with Amendments 33-1 through 33-32, dated 
September 20, 2012.
    If the FAA finds that the regulations in effect on the date of the 
application for the change do not provide adequate or appropriate 
safety standards for the LEAP-1A and -1C engine models because of a 
novel or unusual design feature, special conditions are prescribed 
under the provisions of Sec.  21.16.
    Special conditions are initially applicable to the engine model for 
which they are issued. Should the type certificate for that engine 
model be amended later to include any other engine model that 
incorporates the same novel or unusual design feature, the special 
conditions would also apply to the other engine model under Sec.  
21.101.
    In addition to complying with the applicable product airworthiness 
regulations and special conditions, the LEAP-1A and -1C engine models 
must comply with the fuel venting and exhaust emission requirements of 
14 CFR part 34.
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of the type-
certification basis under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The LEAP-1A and -1C engine models will incorporate the following 
novel or unusual design feature:
    The LEAP-1A and -1C engine models will incorporate woven composite 
fan blades. The woven composite fan blades will have significant 
differences in material property characteristics when compared to 
conventionally designed fan blades using non-composite metallic 
materials. Composite material design provides the capability to 
incorporate multiple load paths and crack arresting features that 
prevent delamination or crack propagation to blade failure during the 
life of the blade.

[[Page 32441]]

    The woven composite fan blades are a novel and unusual design 
feature that requires additional airworthiness standards for type 
certification of the LEAP-1A and -1C engine models.

Discussion of Comments

    A notice of proposed special conditions, No. 33-14-02-SC, for the 
CFM LEAP-1A and--1C engine models was published in the Federal Register 
on Friday, November 14, 2014 (79 FR 68137). No comments were received 
and the special conditions are adopted as proposed.

Applicability

    As discussed above, these special conditions are applicable to the 
LEAP -1A and -1C engine models. Should CFM apply at a later date for a 
change to the type certificate to include another model on the same 
type certificate incorporating the same novel or unusual design 
feature, the special conditions would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on LEAP-1A and -1C engine models. It is not a rule of general 
applicability and applies only to CFM, who requested FAA approval of 
this engine feature.

List of Subjects in 14 CFR Part 33

    Aircraft, Engines, Aviation Safety, Reporting and recordkeeping 
requirements.

    The authority citation for these special conditions is as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for CFM LEAP-1A and -1C engine models.

1. Part 33, Requirements

    In addition to the airworthiness standards in 14 CFR part 33, 
effective February 1, 1965, with Amendments 33-1 through 33-32 
applicable to the LEAP-1A and -1C engine models, CFM will:
    (a) Conduct an engine fan blade containment test with the fan blade 
failing at the inner annulus flow path line instead of at the outermost 
retention groove.
    (b) Substantiate by test and analysis, or other methods acceptable 
to the FAA, that a fan disk and fan blade retention system with minimum 
material properties can withstand, without failure, a centrifugal load 
equal to two times the maximum load the retention system could 
experience within approved engine operating limitations. The fan blade 
retention system includes the portion of the fan blade from the inner 
annulus flow path line inward to the blade dovetail, the blade 
retention components, and the fan disk and fan blade attachment 
features.
    (c) Using a procedure approved by the FAA, establish an operating 
limitation that specifies the maximum allowable number of start-stop 
stress cycles for the fan blade retention system. The life evaluation 
must include the combined effects of high-cycle and low-cycle fatigue. 
If the operating limitation is less than 100,000 cycles, that 
limitation must be specified in Chapter 5 of the Engine Manual 
Airworthiness Limitations Section. The procedure used to establish the 
maximum allowable number of start-stop stress cycles for the fan blade 
retention system will incorporate the integrity requirements in 
paragraphs (c)(1), (c)(2), and (c)(3) of these special conditions for 
the fan blade retention system.
    (1) An engineering plan, which establishes and maintains that the 
combinations of loads, material properties, environmental influences, 
and operating conditions, including the effects of parts influencing 
these parameters, are well known or predictable through validated 
analysis, test, or service experience.
    (2) A manufacturing plan that identifies the specific manufacturing 
constraints necessary to consistently produce the fan blade retention 
system with the attributes required by the engineering plan.
    (3) A service management plan that defines in-service processes for 
maintenance and repair of the fan blade retention system, which will 
maintain attributes consistent with those required by the engineering 
plan.
    (d) Substantiate by test and analysis, or other methods acceptable 
to the FAA, that the blade design below the inner annulus flow path 
line provides multiple load paths and crack arresting features that 
prevent delamination or crack propagation to blade failure during the 
life of the blade.
    (e) Substantiate that during the service life of the engine, the 
total probability of an individual blade retention system failure 
resulting from all possible causes, as defined in Sec.  33.75, will be 
extremely improbable with a cumulative calculated probability of 
failure of less than 10^-9 per engine flight hour.
    (f) Substantiate by test or analysis that not only will the engine 
continue to meet the requirements of Sec.  33.75 following a lightning 
strike on the composite fan blade structure, but that the lightning 
strike will not cause damage to the fan blades that would prevent 
continued safe operation of the affected engine.
    (g) Account for the effects of in-service deterioration, 
manufacturing variations, minimum material properties, and 
environmental effects during the tests and analyses required by 
paragraphs (a), (b), (c), (d), (e), and (f) of these special 
conditions.
    (h) Propose fleet leader monitoring and field sampling programs 
that will monitor the effects of engine fan blade usage and fan blade 
retention system integrity.
    (i) Mark each fan blade legibly and permanently with a part number 
and a serial number.

    Issued in Burlington, Massachusetts, on June 1, 2015.
Ann C. Mollica,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-14084 Filed 6-8-15; 8:45 am]
 BILLING CODE 4910-13-P

32440 Federal Register / Vol. 80, No. 110 / Tuesday, June 9, 2015 / Rules and Regulations

Accordingly, 7 CFR part 633 is SUMMARY: These special conditions are for the new woven composite design fan
amended as follows: issued for the CFM International (CFM), blades.
LEAP–1A and –1C engine models.
PART 633—WATER BANK PROGRAM Type Certification Basis
These engine models will have a novel
or unusual design feature associated Under the provisions of Title 14, Code
■ 1. The authority citation for part 633 with the engine fan blades—new woven of Federal Regulations (14 CFR) 21.17,
continues to read as follows: composite fan blades. The applicable CFM must show that the LEAP–1A and
Authority: 16 U.S.C. 1301–1311. airworthiness regulations do not contain –1C engine models meet the applicable
adequate or appropriate safety standards provisions of the applicable regulations
■ 2. Section 633.2 is amended by in effect on the date of application,
for this design feature. These special
revising the definition for ‘‘Person’’ and except as detailed in paragraphs
conditions contain the additional safety
adding a definition in alphabetical order 21.101(b) and (c). The FAA has
standards that the Administrator
for ‘‘Privately-owned’’ to read as determined the following certification
considers necessary to establish a level
follows: basis for the LEAP–1A and –1C engine
of safety equivalent to that established
§ 633.2 Definitions. by the existing airworthiness standards. models:
* * * * * DATES: Effective July 9, 2015. 1. 14 CFR part 33, ‘‘Airworthiness
Person means one or more FOR FURTHER INFORMATION CONTACT: For Standards: Aircraft Engines,’’ dated
individuals, partnerships, associations, technical questions concerning this February 1, 1965, with Amendments
corporations, estates or trusts, or other action, contact Alan Strom, ANE–111, 33–1 through 33–32, dated September
business enterprises or other legal Engine and Propeller Directorate, 20, 2012.
entities and, whenever applicable, an Aircraft Certification Service, 12 New If the FAA finds that the regulations
Indian tribe, a State, a political England Executive Park, Burlington, in effect on the date of the application
subdivision of a State, or any agency Massachusetts 01803; telephone (781) for the change do not provide adequate
thereof. 238–7143; facsimile (781) 238–7199; or appropriate safety standards for the
email alan.strom@faa.gov. LEAP–1A and –1C engine models
* * * * *
For legal questions concerning this because of a novel or unusual design
Privately-owned means owned or
action, contact Vincent Bennett, ANE–7, feature, special conditions are
operated by a person other than a State,
Engine and Propeller Directorate, prescribed under the provisions of
a political subdivision of a State, or any
Aircraft Certification Service, 12 New § 21.16.
agency thereof.
England Executive Park, Burlington, Special conditions are initially
* * * * * applicable to the engine model for
Massachusetts 01803; telephone (781)
■ 3. Section 633.4 is amended by which they are issued. Should the type
238–7044; facsimile (781) 238–7055;
revising paragraph (d)(2) to read as email vincent.bennett@faa.gov. certificate for that engine model be
follows: amended later to include any other
SUPPLEMENTARY INFORMATION:
§ 633.4 Program requirements.
engine model that incorporates the same
Background novel or unusual design feature, the
* * * * * special conditions would also apply to
(d) * * * On June 27, 2012, CFM International
(CFM) applied for a type certificate for the other engine model under § 21.101.
(2) Lands owned by an agency of the In addition to complying with the
United States other than land held in their new LEAP–1A and –1C engine
models. The LEAP engine models are applicable product airworthiness
trust for Indian Tribes; regulations and special conditions, the
high-bypass-ratio engines that
* * * * * incorporate a novel and unusual design LEAP–1A and –1C engine models must
Signed this 29 day of May, 2015 in feature—new woven composite fan comply with the fuel venting and
Washington, DC blades. The woven composite fan blades exhaust emission requirements of 14
Jason A. Weller, will have significant differences in CFR part 34.
Chief, Natural Resources Conservation material property characteristics when The FAA issues special conditions, as
Service. compared to conventionally designed defined in 14 CFR 11.19, in accordance
[FR Doc. 2015–13992 Filed 6–8–15; 8:45 am] fan blades using non-composite metallic with § 11.38, and they become part of
BILLING CODE 3410–16–P materials. the type-certification basis under
Special conditions are required to § 21.17(a)(2).
ensure that the LEAP–1A and –1C
Novel or Unusual Design Features
woven composite design fan blades
DEPARTMENT OF TRANSPORTATION The LEAP–1A and –1C engine models
account for the differences in material
Federal Aviation Administration properties and failure modes relative to will incorporate the following novel or
conventional single-load path metallic unusual design feature:
14 CFR Part 33 blades. In addition, different The LEAP–1A and –1C engine models
containment requirements may be will incorporate woven composite fan
[Docket No. FAA–2014–0637; Special applied provided CFM shows that the blades. The woven composite fan blades
Conditions No. 33–015–SC] blade design below the inner annulus will have significant differences in
flow path line provides multiple load material property characteristics when
Special Conditions: CFM International, paths and crack arresting features that compared to conventionally designed
LEAP–1A and –1C Engine Models; prevent delamination or crack fan blades using non-composite metallic
tkelley on DSK3SPTVN1PROD with RULES

Incorporation of Woven Composite propagation to blade failure during the materials. Composite material design
Fan Blades life of the blade. provides the capability to incorporate
AGENCY: Federal Aviation These special conditions are multiple load paths and crack arresting
Administration (FAA), DOT. necessary because the applicable features that prevent delamination or
airworthiness regulations do not contain crack propagation to blade failure
ACTION: Final special conditions.
adequate or appropriate safety standards during the life of the blade.

VerDate Sep<11>2014 15:56 Jun 08, 2015 Jkt 235001 PO 00000 Frm 00002 Fmt 4700 Sfmt 4700 E:\FR\FM\09JNR1.SGM 09JNR1

Federal Register / Vol. 80, No. 110 / Tuesday, June 9, 2015 / Rules and Regulations 32441

The woven composite fan blades are failure, a centrifugal load equal to two meet the requirements of § 33.75
a novel and unusual design feature that times the maximum load the retention following a lightning strike on the
requires additional airworthiness system could experience within composite fan blade structure, but that
standards for type certification of the approved engine operating limitations. the lightning strike will not cause
LEAP–1A and –1C engine models. The fan blade retention system includes damage to the fan blades that would
the portion of the fan blade from the prevent continued safe operation of the
Discussion of Comments inner annulus flow path line inward to affected engine.
A notice of proposed special the blade dovetail, the blade retention (g) Account for the effects of in-
conditions, No. 33–14–02–SC, for the components, and the fan disk and fan service deterioration, manufacturing
CFM LEAP–1A and—1C engine models blade attachment features. variations, minimum material
was published in the Federal Register (c) Using a procedure approved by the properties, and environmental effects
on Friday, November 14, 2014 (79 FR FAA, establish an operating limitation during the tests and analyses required
68137). No comments were received and that specifies the maximum allowable by paragraphs (a), (b), (c), (d), (e), and
the special conditions are adopted as number of start-stop stress cycles for the (f) of these special conditions.
proposed. fan blade retention system. The life (h) Propose fleet leader monitoring
evaluation must include the combined and field sampling programs that will
Applicability effects of high-cycle and low-cycle monitor the effects of engine fan blade
As discussed above, these special fatigue. If the operating limitation is less usage and fan blade retention system
conditions are applicable to the LEAP than 100,000 cycles, that limitation integrity.
–1A and –1C engine models. Should must be specified in Chapter 5 of the (i) Mark each fan blade legibly and
CFM apply at a later date for a change Engine Manual Airworthiness permanently with a part number and a
to the type certificate to include another Limitations Section. The procedure serial number.
model on the same type certificate used to establish the maximum
incorporating the same novel or unusual allowable number of start-stop stress Issued in Burlington, Massachusetts, on
June 1, 2015.
design feature, the special conditions cycles for the fan blade retention system
would apply to that model as well. will incorporate the integrity Ann C. Mollica,
requirements in paragraphs (c)(1), (c)(2), Acting Manager, Engine and Propeller
Conclusion Directorate, Aircraft Certification Service.
and (c)(3) of these special conditions for
This action affects only certain novel the fan blade retention system. [FR Doc. 2015–14084 Filed 6–8–15; 8:45 am]
or unusual design features on LEAP–1A (1) An engineering plan, which BILLING CODE 4910–13–P
and –1C engine models. It is not a rule establishes and maintains that the
of general applicability and applies only combinations of loads, material
to CFM, who requested FAA approval of properties, environmental influences, DEPARTMENT OF TRANSPORTATION
this engine feature. and operating conditions, including the
Federal Aviation Administration
List of Subjects in 14 CFR Part 33 effects of parts influencing these
parameters, are well known or
Aircraft, Engines, Aviation Safety, 14 CFR Part 39
predictable through validated analysis,
Reporting and recordkeeping test, or service experience. [Docket No. FAA–2014–0227; Directorate
requirements. (2) A manufacturing plan that Identifier 2013–NM–211–AD; Amendment
The authority citation for these identifies the specific manufacturing 39–18165; AD 2015–11–02]
special conditions is as follows: constraints necessary to consistently RIN 2120–AA64
Authority: 49 U.S.C. 106(g), 40113, 44701, produce the fan blade retention system
44702, 44704. with the attributes required by the Airworthiness Directives; Lockheed
engineering plan. Martin Corporation/Lockheed Martin
The Special Conditions (3) A service management plan that Aeronautics Company Airplanes
Accordingly, pursuant to the defines in-service processes for
authority delegated to me by the maintenance and repair of the fan blade AGENCY: Federal Aviation
Administrator, the following special retention system, which will maintain Administration (FAA), DOT.
conditions are issued as part of the type attributes consistent with those required ACTION: Final rule.
certification basis for CFM LEAP–1A by the engineering plan.
and –1C engine models. (d) Substantiate by test and analysis, SUMMARY: We are superseding
or other methods acceptable to the FAA, Airworthiness Directive (AD) 95–26–11
1. Part 33, Requirements that the blade design below the inner for all Lockheed Martin Corporation/
In addition to the airworthiness annulus flow path line provides Lockheed Martin Aeronautics Company
standards in 14 CFR part 33, effective multiple load paths and crack arresting Model L–1011 series airplanes. AD 95–
February 1, 1965, with Amendments features that prevent delamination or 26–11 required repetitive inspections to
33–1 through 33–32 applicable to the crack propagation to blade failure detect cracking of the fittings that attach
LEAP–1A and –1C engine models, CFM during the life of the blade. the aft pressure bulkhead to the fuselage
will: (e) Substantiate that during the stringers, repetitive inspections to detect
(a) Conduct an engine fan blade service life of the engine, the total cracking of the fittings and of the splice
containment test with the fan blade probability of an individual blade tab of the aft pressure bulkhead, and
failing at the inner annulus flow path retention system failure resulting from corrective actions if necessary. This new
line instead of at the outermost all possible causes, as defined in AD requires repetitive inspections to
tkelley on DSK3SPTVN1PROD with RULES

retention groove. § 33.75, will be extremely improbable detect cracking of the fittings that attach
(b) Substantiate by test and analysis, with a cumulative calculated probability the aft pressure bulkhead to the fuselage
or other methods acceptable to the FAA, of failure of less than 10¥9 per engine stringers, repetitive inspections to detect
that a fan disk and fan blade retention flight hour. cracking of the fittings and of the splice
system with minimum material (f) Substantiate by test or analysis that tab of the aft pressure bulkhead,
properties can withstand, without not only will the engine continue to repetitive inspections for cracking of

VerDate Sep<11>2014 15:56 Jun 08, 2015 Jkt 235001 PO 00000 Frm 00003 Fmt 4700 Sfmt 4700 E:\FR\FM\09JNR1.SGM 09JNR1

Document Created: 2015-12-15 15:25:02
Document Modified: 2015-12-15 15:25:02

Category		Regulatory Information
Collection		Federal Register
sudoc Class		AE 2.7: GS 4.107: AE 2.106:
Publisher		Office of the Federal Register, National Archives and Records Administration
Section		Rules and Regulations
Action		Final special conditions.
Dates		Effective July 9, 2015.
Contact		For technical questions concerning this action, contact Alan Strom, ANE-111, Engine and Propeller Directorate, Aircraft Certification Service, 12 New England Executive Park, Burlington, Massachusetts 01803; telephone (781) 238-7143; facsimile (781) 238-7199; email [email protected]
FR Citation		80 FR 32440
CFR Associated		Aircraft; Engines; Aviation Safety and Reporting and Recordkeeping Requirements

80 FR 32440 - Special Conditions: CFM International, LEAP-1A and -1C Engine Models; Incorporation of Woven Composite Fan Blades

DEPARTMENT OF TRANSPORTATIONFederal Aviation Administration

Federal Register Volume 80, Issue 110 (June 9, 2015)

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration