Special Conditions: General Electric Company, GE9X Engine Models; Endurance Test Special Conditions, 53400-53403 [2017-24812]
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Federal Register / Vol. 82, No. 220 / Thursday, November 16, 2017 / Rules and Regulations
TABLE I—Continued
Variety
Regulation period
Minimum grade
Minimum
diameter
(inches)
(1)
(2)
(3)
(4)
*
*
*
*
*
*
*
(b) * * *
TABLE II
Variety
Regulation period
Minimum grade
Minimum
diameter
(inches)
(1)
(2)
(3)
(4)
Oranges
Early and midseason ...............................
Navel .................................................
Temple ..............................................
Valencia and other late type .............
*
*
*
01/29/90–08/19/90 ..................................
On and after 08/20/90 .............................
On and after 11/24/89 .............................
On and after 11/24/89 .............................
March 23, 1992–9/27/92 .........................
On and after 9/28/92 ...............................
*
*
*
*
*
[Subpart Redesignated as Subpart E
and Amended]
7. Redesignate ‘‘Subpart—Interpretive
Rule’’ as subpart E and revise the
heading to read as follows:
■
Subpart E—Interpretations
Dated: November 9, 2017.
Bruce Summers,
Acting Administrator, Agricultural Marketing
Service.
[FR Doc. 2017–24701 Filed 11–15–17; 8:45 am]
BILLING CODE 3410–02–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 33
[Docket No. FAA–2017–0537; Notice No. 33–
17–02–SC]
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Special Conditions: General Electric
Company, GE9X Engine Models;
Endurance Test Special Conditions
Federal Aviation
Administration (FAA), DOT.
ACTION: Final special conditions.
These special conditions are
issued for the General Electric Company
turbofan engine models GE9X–105B1A,
–105B1A1, –105B1A2, –105B1A3,
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14:33 Nov 15, 2017
Jkt 244001
No.
No.
No.
No.
No.
No.
–102B1A, –102B1A1, –102B1A2,
–102B1A3, and –93B1A. In these special
conditions, the engine models will be
referred to as ‘‘GE9X.’’ The engines will
have novel or unusual design features
associated with the engine design. The
applicable airworthiness regulations do
not contain adequate or appropriate
safety standards for these design
features. 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 December 18, 2017.
FOR FURTHER INFORMATION CONTACT:
Diane Cook, AIR–6A1, Engine and
Propeller Standards Branch, Aircraft
Certification Service, 1200 District
Avenue, Burlington, Massachusetts
01803–5213; telephone (781) 238–7111;
facsimile (781) 238–7199; email
diane.cook@faa.gov.
SUPPLEMENTARY INFORMATION:
On January 29, 2016, General Electric
Company (GE) applied for a type
certificate for their new GE9X turbofan
engine models. The GE9X engine
models are high-bypass-ratio engines
that incorporate novel or unusual design
features. The GE9X engine models
incorporate new technologies such that
the company cannot run the endurance
test conditions prescribed in § 33.87
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Background
AGENCY:
SUMMARY:
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24⁄16
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without significant modifications
making the test vehicle nonrepresentative of the type design.
Discussion
An alternative endurance test cycle
has been developed that provides a level
of safety equivalent with that intended
by § 33.87. The alternate endurance test
provides the test conditions that allow
the engine to be run in type design
configuration and demonstrate engine
operability and durability as well as
systems functionality to a level intended
by the current § 33.87 rule.
These special conditions provide the
necessary conditions for verification of
engine-level and component-level
effects as intended by the current
§ 33.87 Endurance test. The test is run
in engine type design configuration,
with only limited test enabling
modifications as needed. The special
conditions include a demonstration for
the oil, fuel, air bleed, and accessory
drive systems as required in the current
§ 33.87 Endurance test.
The equivalent level of severity
intended by the § 33.87 Endurance test
is provided by an engine test
demonstration at the gas path limiting
temperature and at shaft speed redlines
and at the most extreme shaft speeds as
determined through a critical point
analysis (CPA). In addition, times on
condition and cycle counts were
developed to allow additional
challenges to the novel or unusual
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Federal Register / Vol. 82, No. 220 / Thursday, November 16, 2017 / Rules and Regulations
design features that would not have
been as challenged by the current
§ 33.87 test schedule.
The level of durability is equivalent
with that intended by the rule, which
considers the damage accumulated
during the test for the limiting damage
mechanisms for components and engine
systems, up to and including the
applicable limitations declared in the
Type Certificate Data Sheets (TCDS).
The alternate test schedule provides
conditions in the engine for a sufficient
amount of time to demonstrate that no
potential safety issue will develop from
the limiting damage mechanisms while
operating in service.
The special conditions for §§ 33.4 and
33.29 are added to support an
equivalent compliance by means of
mandatory inspections prescribed in
paragraph (b)(3) of the § 33.87 special
conditions. These special condition
requirements maintain a level of safety
equivalent to the level intended by the
applicable airworthiness standards in
effect on the date of application.
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Type Certification Basis
Under the provisions of Title 14, Code
of Federal Regulations (14 CFR) 21.17,
GE must show that the GE9X engine
models meet the applicable provisions
of part 33, as amended by Amendments
33–1 through 33–34. The FAA has
determined that the applicable
airworthiness regulations in part 33 do
not contain adequate or appropriate
safety standards for the GE9X engine
models because of their novel or
unusual engine design features.
Therefore, these special conditions are
prescribed under the provisions of 14
CFR 11.19 and 21.16, and will become
part of the type certification basis for
GE9X engine models in accordance with
§ 21.17(a)(2).
Novel or Unusual Design Features
The GE9X engine models will
incorporate the following novel or
unusual design features: Technological
advances that reduce noise and
emissions while improving fuel
efficiency and increasing thrust, when
compared to previous similarly
certificated GE engine models. The
technological advances are incorporated
into hardware design, materials, and
engine operating characteristics.
Introduction of complex cooling
systems and film-cooled components
cause metal temperatures to be
significantly influenced by cooling air
temperatures and air flows and are no
longer in direct proportion to the gas
path temperature which is a target of the
current endurance test. Introduction of
new materials, new design features, and
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operating conditions also introduced
new failure modes that are not targeted
by the current endurance test cycle.
Some of the technological
advancements were introduced in prior
GE engine models and mitigated by
modifications to the test engine.
For past certifications, GE has shown
that the engine design, as modified, still
represented the durability and operating
characteristics of the intended type
design but the modifications needed to
the GE9X engine model to run the
§ 33.87 Endurance test cannot be
reconciled and would affect the test
outcome.
Discussion of Comments
Notice of proposed special conditions
No. 33–17–02–SC for the GE9X engine
models was published in the Federal
Register on 82 FR 28790. We received
one comment from an anonymous
commenter that acknowledged the need
for special conditions as it concerns the
GE9X engines models. We understand
and acknowledge the comment we
received, which is supportive of a
special condition for the GE9X engine
model. No further response is required.
Applicability
As discussed above, the special
conditions are applicable to the GE9X
engine model(s). Should GE 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 the GE9X
turbofan engine models. It is not a rule
of general applicability and applies only
to GE, 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 the GE9X engine models:
GE9X–105B1A, –105B1A1, –105B1A2,
–105B1A3, –102B1A, –102B1A1,
102B1A2, –102B1A3, and –93B1A.
■
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53401
PART 33—REQUIREMENTS
§ 33.4 Instructions for Continued
Airworthiness
The Airworthiness Limitations
section must prescribe the mandatory
post-flight inspections and maintenance
actions associated with any exceedance
required by the endurance test,
paragraph (b)(3), of these special
conditions.
§ 33.29
Instrument Connection
The engine must have means, or
provisions for means, to automatically
record and alert maintenance personnel
of each occurrence of any exceedance
required by the endurance test
paragraph (b)(3), of these special
conditions.
§ 33.87
Endurance Test
(a) General: The applicant must show
that the endurance test schedule in
combination with any prescribed
mandatory actions provide an
equivalent level of severity and
demonstration of durability and
operability as that intended by
§ 33.87(a) and (b). When showing that
the level of durability is equivalent with
that intended by the rule, the applicant
must consider the damage accumulated
during the test for the limiting damage
mechanisms for components and engine
systems, up to and including the
applicable limitations declared in the
type certificate data sheets (TCDS). The
test cycle content must create
conditions in the engine for a sufficient
amount of time to demonstrate no
potential safety issue will develop from
the limiting damage mechanisms while
operating in service. The following
minimum requirements apply:
(1) Conduct the tests in paragraphs
(b), (c), and (d) of these special
conditions, for total cumulative and
dwell time duration between ground
idle and the takeoff thrust prescribed in
these special conditions. The test cycle
durations must include all maximums
allowed in the TCDS and expected
service operation.
(2) Requirements of § 33.87(a)(1), (2),
(4), and (6).
(3) Requirements of § 33.87(a)(3)
applicable to the temperature of external
surfaces of the engine.
(4) Testing for maximum air bleed
must be at least equal with the
prescribed test required in § 33.87(a)(5).
However, for these cycles, the thrust or
the rotor shaft rotational speed may be
less than 100 percent of the value
associated with the particular operation
being tested if the FAA finds that the
validity of the endurance test is not
compromised.
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Federal Register / Vol. 82, No. 220 / Thursday, November 16, 2017 / Rules and Regulations
(5) Testing for engine fuel, oil, and
hydraulic fluid pressure and oil
temperature must be at least equal with
the prescribed test required in
§ 33.87(a)(7).
(6) If the number of occurrences of
either transient rotor shaft overspeed or
transient gas over temperature is not
limited, at least 155 accelerations must
be made at the limiting overspeed or
over temperature. If the number of
occurrences is limited, that number of
accelerations must be made at the
limiting overspeed or over temperature.
(7) One hundred starts must be made,
of which:
(i) Twenty-five starts must be
preceded by at least a two-hour engine
shutdown.
(ii) Ten false engine starts must be
accomplished, pausing for the
applicant’s specified minimum fuel
drainage time, before attempting a
normal start.
(iii) Ten normal restarts must be
accomplished with not longer than 15
minutes since engine shutdown.
The remaining starts may be made
after completing the endurance testing
prescribed by these special conditions.
(8) Unless otherwise specified (i.e.
(d)(2) of these special conditions), for
accelerations from ground idle to
takeoff, the throttle must be moved in
not more than one second, except that,
if different regimes of control operations
are incorporated necessitating
scheduling of the thrust-control lever
motion in going from one extreme
position to the other, a longer period of
time is acceptable, but not more than
two seconds.
(i) When operating with max oil
temperatures the throttle movement
may be ‘stair-stepped’ to allow for oil
temperature stabilization for durations
greater than two seconds.
(9) The applicant must validate any
analytical methods used for compliance
with these special conditions.
Validation includes the ability to
accurately predict an outcome
applicable to the engine being tested.
(10) The applicant must perform the
endurance test on an engine that
substantially conforms to its type
design. Modifications may be made as
needed to achieve test conditions and/
or engine operating conditions
representative of the type design.
(b) Conduct the endurance test at or
above the declared shaft speeds and gas
temperatures limits, and at or above
conditions representative of critical
points (speeds, temperatures, rated
thrust) in the operating envelope.
(1) Conduct the endurance test at or
above the rated takeoff thrust and rated
maximum continuous thrust and with
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the associated limits for rotor speeds
and gas temperature (redlines), as
follows:
(i) Either rotor speed or gas
temperature, or concurrent rotor speed
and gas temperature, if analysis
indicates a combination of redline
operational conditions is possible to
occur in service, must be at least 100
percent of the values associated with the
engine rating being tested.
(ii) The cumulative test time duration
and number of cycles must be
representative of the rotor speed and gas
temperature excursions to redlines that
can be expected to occur in between
overhauls.
(iii) The time durations for each
takeoff or maximum continuous
segment must include all maximums
allowed in the TCDS and expected
service operation and must include the
following cycles:
(A) At least one (1) takeoff cycle of
5-minutes time duration at the low
pressure rotor speed limit and gas
temperature limit (redlines).
(B) At least one (1) takeoff cycle of
5-minutes time duration at the high
pressure rotor speed limit and gas
temperature limit (redlines).
(C) In lieu of the separate cycles
specified in paragraphs (A) and (B) of
this section, the applicant may run the
low pressure and high pressure rotor
speeds and gas temperature limits
(redlines) in the same cycle. However,
in this case, the applicant must run at
least 2 cycles of 5 minutes’ time
duration each.
(2) Conduct the endurance test at or
above the rated takeoff thrust and the
rated maximum continuous thrust with
rotor speeds at or above those
determined by a critical point analysis
(CPA) and with gas temperature redline
conditions as follows:
(i) The applicant must determine
through a CPA the highest rotor shaft
rotational speeds (CPA speeds) expected
to occur for each rotor shaft system
within the declared operating envelope.
The CPA must be conducted for the
takeoff and maximum continuous rated
thrust and must consider the declared
operating envelope, engine
deterioration, engine-to-engine
variability, and any other applicable
variables that can cause the engine to
operate at the extremes of its
performance ratings.
(ii) Except as provided in paragraph
(b)(3)(ii) of these special conditions,
conduct a cyclic test between ground
idle and combined takeoff and
maximum continuous thrust ratings, as
follows:
(A) Eighteen hours and forty-five
minutes (18.75 hours) cumulated time
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duration at or above the rated takeoff
thrust, the gas temperature limit for
takeoff (redline), and the CPA rotor
speeds for takeoff determined per
paragraph (b)(2)(i) of these special
conditions.
(B) Forty-five (45) hours cumulated
time duration at or above the rated
maximum continuous thrust, the gas
temperature limit for maximum
continuous (redline), and the CPA rotor
speeds for maximum continuous
determined per paragraph (b)(2)(i) of
these special conditions.
(C) The time durations for each
takeoff or maximum continuous
segments must include all maximums
allowed in the TCDS and expected
service operation, and must include at
least one maximum continuous cycle of
30 minutes run continuously.
(3) If the cyclic shaft speed excursions
specified in paragraphs (b)(1) or (b)(2) of
these special conditions cannot be
demonstrated in the test, then an
alternative equivalent with the rule
intent must be provided. Alternatives
may include alternate means of test
demonstration, mandatory actions, or
other means found acceptable to the
FAA. The applicant must prescribe a
mandatory action plan for engine
operation between the shaft speeds
demonstrated for a minimum of
cumulated 18.75 hours at or above rated
takeoff and 45 hours at or above rated
maximum continuous, respectively, and
the declared speed limits (redlines), as
follows:
(i) Prescribe post-event actions or
operating limitations acceptable to the
FAA for operation below the declared
speed limits (redlines) and above the
CPA speeds.
(ii) If the test required by (b)(2)(ii) of
these special conditions can only be
accomplished at a rotor shaft speed
lower than the CPA speed, prescribe
post-event actions or operating
limitations acceptable to the FAA for
operation below that CPA speed and
above the value demonstrated during
the test.
(c) Conduct the endurance test at the
incremental cruise thrust that must be at
least equal with the prescribed test
required in § 33.87(b)(4). The 25
incremental test cycles must be
uniformly distributed throughout the
entire endurance test.
(d) Conduct at least 300 cycles
between ground idle and combined
rated takeoff and rated maximum
continuous thrust, as follows:
(1) Each cycle to include acceleration
to or above rated takeoff thrust,
deceleration from takeoff to ground idle,
followed by 5 to 15 seconds at ground
idle, acceleration to or above rated
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Federal Register / Vol. 82, No. 220 / Thursday, November 16, 2017 / Rules and Regulations
maximum continuous thrust, and
deceleration to ground idle.
(2) The throttle movement from
ground idle to rated takeoff or maximum
continuous thrust and from rated takeoff
thrust to ground idle should be not more
than one (1) second, except that, if
different regimes of control operations
are incorporated necessitating
scheduling of the thrust-control lever
motion in going from one extreme
position to the other, a longer period of
time is acceptable, but not more than
two (2) seconds. The throttle movement
from rated maximum continuous thrust
to ground idle should not be more than
five (5) seconds.
(3) The time durations for each cycle
associated with either takeoff or
maximum continuous thrust segments
must include all maximums allowed in
the TCDS and expected service
operation, and must include the
following cycles:
(i) Three (3) cycles of 5 minutes each
and one (1) cycle of 10 minutes at the
takeoff thrust.
(ii) Three (3) cycles of 30 minutes
each at the maximum continuous thrust.
Issued in Burlington, Massachusetts, on
November 8, 2017.
Robert J. Ganley,
Manager, Engine and Propeller Standards
Branch, Aircraft Certification Service.
[FR Doc. 2017–24812 Filed 11–15–17; 8:45 am]
BILLING CODE 4910–13–P
53403
determinations in Order No. 831, which
amended its regulations to address
incremental energy offer caps in markets
operated by regional transmission
organizations and independent system
operators.
DATES:
This rule is effective January 16,
2018.
FOR FURTHER INFORMATION CONTACT:
DEPARTMENT OF ENERGY
Federal Energy Regulatory
Commission
18 CFR Part 35
[Docket No. RM16–5–001; Order No. 831–
A]
Offer Caps in Markets Operated by
Regional Transmission Organizations
and Independent System Operators
Federal Energy Regulatory
Commission, Department of Energy.
ACTION: Order on rehearing and
clarification.
AGENCY:
The Federal Energy
Regulatory Commission is granting in
part and denying in part requests for
rehearing and clarification of its
SUMMARY:
Emma Nicholson (Technical
Information), Office of Energy Policy
and Innovation, Federal Energy
Regulatory Commission, 888 First
Street NE., Washington, DC 20426,
(202) 502–8846, emma.nicholson@
ferc.gov
Pamela Quinlan (Technical
Information), Office of Energy Market
Regulation, Federal Energy Regulatory
Commission, 888 First Street NE.,
Washington, DC 20426, (202) 502–
6179, pamela.quinlan@ferc.gov
Anne Marie Hirschberger (Legal
Information), Office of the General
Counsel, Federal Energy Regulatory
Commission, 888 First Street NE.,
Washington, DC 20426, (202) 502–
8387, annemarie.hirschberger@
ferc.gov
SUPPLEMENTARY INFORMATION:
TABLE OF CONTENTS
Paragraph Nos.
I. Introduction ...............................................................................................................................................................................
II. Discussion ................................................................................................................................................................................
A. Offer Cap Structure ..........................................................................................................................................................
1. Hard Cap Level ..........................................................................................................................................................
2. Implementation of the Hard Cap ..............................................................................................................................
B. Verification Requirement .................................................................................................................................................
1. Expected Costs ...........................................................................................................................................................
2. Verification of Imports ..............................................................................................................................................
C. Costs Included in Cost-Based Incremental Energy Offers ..............................................................................................
1. Requests for Rehearing/Clarification ........................................................................................................................
2. Determination .............................................................................................................................................................
III. Information Collection Statement ..........................................................................................................................................
IV. Regulatory Flexibility Act Certification ................................................................................................................................
V. Document Availability ............................................................................................................................................................
VI. Effective Date ..........................................................................................................................................................................
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I. Introduction
1. On November 17, 2016, the Federal
Energy Regulatory Commission
(Commission) issued Order No. 831.1
Order No. 831 addresses the
incremental energy offer component of
a resource’s supply offer, which is a
financial component consisting of costs
that vary with a resource’s output or
level of demand reduction. Incremental
energy offers are one of the components
used to calculate locational marginal
1 Offer Caps in Markets Operated by Regional
Transmission Organizations and Independent
System Operators, 81 FR 87,770 (Dec. 5, 2016),
FERC Stats. & Regs. ¶ 31,387 (2016) (Order No.
831).
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prices (LMPs). California Independent
System Operator Corporation (CAISO),
ISO New England Inc. (ISO–NE),
Midcontinent Independent System
Operator, Inc. (MISO), New York
Independent System Operator, Inc.
(NYISO), and Southwest Power Pool,
Inc. (SPP) currently have a $1,000/MWh
cap on incremental energy offers (offer
cap), and PJM Interconnection, L.L.C.
(PJM) currently has an offer cap of
$2,000/MWh on cost-based offers.2
2. In Order No. 831, the Commission
amended its regulations to require that
each regional transmission organization
2 Order No. 831, FERC Stats. & Regs. ¶ 31,387 at
PP 11–13.
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1
5
5
6
13
18
19
30
34
34
37
41
44
45
48
and independent system operator (RTO/
ISO): (1) Cap each resource’s
incremental energy offer at the higher of
$1,000/MWh or that resource’s verified
cost-based incremental energy offer; and
(2) cap verified cost-based incremental
energy offers at $2,000/MWh when
calculating LMPs (hard cap).3 Resources
with verified cost-based incremental
energy offers above $2,000/MWh will be
eligible to receive uplift.4 In response to
comments on the Notice of Proposed
3 Id.
4 Id.
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]]>Agencies
[Federal Register Volume 82, Number 220 (Thursday, November 16, 2017)]
[Rules and Regulations]
[Pages 53400-53403]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-24812]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 33
[Docket No. FAA-2017-0537; Notice No. 33-17-02-SC]
Special Conditions: General Electric Company, GE9X Engine Models;
Endurance Test Special Conditions
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for the General Electric
Company turbofan engine models GE9X-105B1A, -105B1A1, -105B1A2, -
105B1A3, -102B1A, -102B1A1, -102B1A2, -102B1A3, and -93B1A. In these
special conditions, the engine models will be referred to as ``GE9X.''
The engines will have novel or unusual design features associated with
the engine design. The applicable airworthiness regulations do not
contain adequate or appropriate safety standards for these design
features. 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 December 18, 2017.
FOR FURTHER INFORMATION CONTACT: Diane Cook, AIR-6A1, Engine and
Propeller Standards Branch, Aircraft Certification Service, 1200
District Avenue, Burlington, Massachusetts 01803-5213; telephone (781)
238-7111; facsimile (781) 238-7199; email diane.cook@faa.gov.
SUPPLEMENTARY INFORMATION:
Background
On January 29, 2016, General Electric Company (GE) applied for a
type certificate for their new GE9X turbofan engine models. The GE9X
engine models are high-bypass-ratio engines that incorporate novel or
unusual design features. The GE9X engine models incorporate new
technologies such that the company cannot run the endurance test
conditions prescribed in Sec. 33.87 without significant modifications
making the test vehicle non-representative of the type design.
Discussion
An alternative endurance test cycle has been developed that
provides a level of safety equivalent with that intended by Sec.
33.87. The alternate endurance test provides the test conditions that
allow the engine to be run in type design configuration and demonstrate
engine operability and durability as well as systems functionality to a
level intended by the current Sec. 33.87 rule.
These special conditions provide the necessary conditions for
verification of engine-level and component-level effects as intended by
the current Sec. 33.87 Endurance test. The test is run in engine type
design configuration, with only limited test enabling modifications as
needed. The special conditions include a demonstration for the oil,
fuel, air bleed, and accessory drive systems as required in the current
Sec. 33.87 Endurance test.
The equivalent level of severity intended by the Sec. 33.87
Endurance test is provided by an engine test demonstration at the gas
path limiting temperature and at shaft speed redlines and at the most
extreme shaft speeds as determined through a critical point analysis
(CPA). In addition, times on condition and cycle counts were developed
to allow additional challenges to the novel or unusual
[[Page 53401]]
design features that would not have been as challenged by the current
Sec. 33.87 test schedule.
The level of durability is equivalent with that intended by the
rule, which considers the damage accumulated during the test for the
limiting damage mechanisms for components and engine systems, up to and
including the applicable limitations declared in the Type Certificate
Data Sheets (TCDS). The alternate test schedule provides conditions in
the engine for a sufficient amount of time to demonstrate that no
potential safety issue will develop from the limiting damage mechanisms
while operating in service.
The special conditions for Sec. Sec. 33.4 and 33.29 are added to
support an equivalent compliance by means of mandatory inspections
prescribed in paragraph (b)(3) of the Sec. 33.87 special conditions.
These special condition requirements maintain a level of safety
equivalent to the level intended by the applicable airworthiness
standards in effect on the date of application.
Type Certification Basis
Under the provisions of Title 14, Code of Federal Regulations (14
CFR) 21.17, GE must show that the GE9X engine models meet the
applicable provisions of part 33, as amended by Amendments 33-1 through
33-34. The FAA has determined that the applicable airworthiness
regulations in part 33 do not contain adequate or appropriate safety
standards for the GE9X engine models because of their novel or unusual
engine design features. Therefore, these special conditions are
prescribed under the provisions of 14 CFR 11.19 and 21.16, and will
become part of the type certification basis for GE9X engine models in
accordance with Sec. 21.17(a)(2).
Novel or Unusual Design Features
The GE9X engine models will incorporate the following novel or
unusual design features: Technological advances that reduce noise and
emissions while improving fuel efficiency and increasing thrust, when
compared to previous similarly certificated GE engine models. The
technological advances are incorporated into hardware design,
materials, and engine operating characteristics. Introduction of
complex cooling systems and film-cooled components cause metal
temperatures to be significantly influenced by cooling air temperatures
and air flows and are no longer in direct proportion to the gas path
temperature which is a target of the current endurance test.
Introduction of new materials, new design features, and operating
conditions also introduced new failure modes that are not targeted by
the current endurance test cycle. Some of the technological
advancements were introduced in prior GE engine models and mitigated by
modifications to the test engine.
For past certifications, GE has shown that the engine design, as
modified, still represented the durability and operating
characteristics of the intended type design but the modifications
needed to the GE9X engine model to run the Sec. 33.87 Endurance test
cannot be reconciled and would affect the test outcome.
Discussion of Comments
Notice of proposed special conditions No. 33-17-02-SC for the GE9X
engine models was published in the Federal Register on 82 FR 28790. We
received one comment from an anonymous commenter that acknowledged the
need for special conditions as it concerns the GE9X engines models. We
understand and acknowledge the comment we received, which is supportive
of a special condition for the GE9X engine model. No further response
is required.
Applicability
As discussed above, the special conditions are applicable to the
GE9X engine model(s). Should GE 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 the GE9X turbofan engine models. It is not a rule of general
applicability and applies only to GE, 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
0
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 the GE9X engine models: GE9X-105B1A, -
105B1A1, -105B1A2, -105B1A3, -102B1A, -102B1A1, 102B1A2, -102B1A3, and
-93B1A.
PART 33--REQUIREMENTS
Sec. 33.4 Instructions for Continued Airworthiness
The Airworthiness Limitations section must prescribe the mandatory
post-flight inspections and maintenance actions associated with any
exceedance required by the endurance test, paragraph (b)(3), of these
special conditions.
Sec. 33.29 Instrument Connection
The engine must have means, or provisions for means, to
automatically record and alert maintenance personnel of each occurrence
of any exceedance required by the endurance test paragraph (b)(3), of
these special conditions.
Sec. 33.87 Endurance Test
(a) General: The applicant must show that the endurance test
schedule in combination with any prescribed mandatory actions provide
an equivalent level of severity and demonstration of durability and
operability as that intended by Sec. 33.87(a) and (b). When showing
that the level of durability is equivalent with that intended by the
rule, the applicant must consider the damage accumulated during the
test for the limiting damage mechanisms for components and engine
systems, up to and including the applicable limitations declared in the
type certificate data sheets (TCDS). The test cycle content must create
conditions in the engine for a sufficient amount of time to demonstrate
no potential safety issue will develop from the limiting damage
mechanisms while operating in service. The following minimum
requirements apply:
(1) Conduct the tests in paragraphs (b), (c), and (d) of these
special conditions, for total cumulative and dwell time duration
between ground idle and the takeoff thrust prescribed in these special
conditions. The test cycle durations must include all maximums allowed
in the TCDS and expected service operation.
(2) Requirements of Sec. 33.87(a)(1), (2), (4), and (6).
(3) Requirements of Sec. 33.87(a)(3) applicable to the temperature
of external surfaces of the engine.
(4) Testing for maximum air bleed must be at least equal with the
prescribed test required in Sec. 33.87(a)(5). However, for these
cycles, the thrust or the rotor shaft rotational speed may be less than
100 percent of the value associated with the particular operation being
tested if the FAA finds that the validity of the endurance test is not
compromised.
[[Page 53402]]
(5) Testing for engine fuel, oil, and hydraulic fluid pressure and
oil temperature must be at least equal with the prescribed test
required in Sec. 33.87(a)(7).
(6) If the number of occurrences of either transient rotor shaft
overspeed or transient gas over temperature is not limited, at least
155 accelerations must be made at the limiting overspeed or over
temperature. If the number of occurrences is limited, that number of
accelerations must be made at the limiting overspeed or over
temperature.
(7) One hundred starts must be made, of which:
(i) Twenty-five starts must be preceded by at least a two-hour
engine shutdown.
(ii) Ten false engine starts must be accomplished, pausing for the
applicant's specified minimum fuel drainage time, before attempting a
normal start.
(iii) Ten normal restarts must be accomplished with not longer than
15 minutes since engine shutdown.
The remaining starts may be made after completing the endurance
testing prescribed by these special conditions.
(8) Unless otherwise specified (i.e. (d)(2) of these special
conditions), for accelerations from ground idle to takeoff, the
throttle must be moved in not more than one second, except that, if
different regimes of control operations are incorporated necessitating
scheduling of the thrust-control lever motion in going from one extreme
position to the other, a longer period of time is acceptable, but not
more than two seconds.
(i) When operating with max oil temperatures the throttle movement
may be `stair-stepped' to allow for oil temperature stabilization for
durations greater than two seconds.
(9) The applicant must validate any analytical methods used for
compliance with these special conditions. Validation includes the
ability to accurately predict an outcome applicable to the engine being
tested.
(10) The applicant must perform the endurance test on an engine
that substantially conforms to its type design. Modifications may be
made as needed to achieve test conditions and/or engine operating
conditions representative of the type design.
(b) Conduct the endurance test at or above the declared shaft
speeds and gas temperatures limits, and at or above conditions
representative of critical points (speeds, temperatures, rated thrust)
in the operating envelope.
(1) Conduct the endurance test at or above the rated takeoff thrust
and rated maximum continuous thrust and with the associated limits for
rotor speeds and gas temperature (redlines), as follows:
(i) Either rotor speed or gas temperature, or concurrent rotor
speed and gas temperature, if analysis indicates a combination of
redline operational conditions is possible to occur in service, must be
at least 100 percent of the values associated with the engine rating
being tested.
(ii) The cumulative test time duration and number of cycles must be
representative of the rotor speed and gas temperature excursions to
redlines that can be expected to occur in between overhauls.
(iii) The time durations for each takeoff or maximum continuous
segment must include all maximums allowed in the TCDS and expected
service operation and must include the following cycles:
(A) At least one (1) takeoff cycle of 5-minutes time duration at
the low pressure rotor speed limit and gas temperature limit
(redlines).
(B) At least one (1) takeoff cycle of 5-minutes time duration at
the high pressure rotor speed limit and gas temperature limit
(redlines).
(C) In lieu of the separate cycles specified in paragraphs (A) and
(B) of this section, the applicant may run the low pressure and high
pressure rotor speeds and gas temperature limits (redlines) in the same
cycle. However, in this case, the applicant must run at least 2 cycles
of 5 minutes' time duration each.
(2) Conduct the endurance test at or above the rated takeoff thrust
and the rated maximum continuous thrust with rotor speeds at or above
those determined by a critical point analysis (CPA) and with gas
temperature redline conditions as follows:
(i) The applicant must determine through a CPA the highest rotor
shaft rotational speeds (CPA speeds) expected to occur for each rotor
shaft system within the declared operating envelope. The CPA must be
conducted for the takeoff and maximum continuous rated thrust and must
consider the declared operating envelope, engine deterioration, engine-
to-engine variability, and any other applicable variables that can
cause the engine to operate at the extremes of its performance ratings.
(ii) Except as provided in paragraph (b)(3)(ii) of these special
conditions, conduct a cyclic test between ground idle and combined
takeoff and maximum continuous thrust ratings, as follows:
(A) Eighteen hours and forty-five minutes (18.75 hours) cumulated
time duration at or above the rated takeoff thrust, the gas temperature
limit for takeoff (redline), and the CPA rotor speeds for takeoff
determined per paragraph (b)(2)(i) of these special conditions.
(B) Forty-five (45) hours cumulated time duration at or above the
rated maximum continuous thrust, the gas temperature limit for maximum
continuous (redline), and the CPA rotor speeds for maximum continuous
determined per paragraph (b)(2)(i) of these special conditions.
(C) The time durations for each takeoff or maximum continuous
segments must include all maximums allowed in the TCDS and expected
service operation, and must include at least one maximum continuous
cycle of 30 minutes run continuously.
(3) If the cyclic shaft speed excursions specified in paragraphs
(b)(1) or (b)(2) of these special conditions cannot be demonstrated in
the test, then an alternative equivalent with the rule intent must be
provided. Alternatives may include alternate means of test
demonstration, mandatory actions, or other means found acceptable to
the FAA. The applicant must prescribe a mandatory action plan for
engine operation between the shaft speeds demonstrated for a minimum of
cumulated 18.75 hours at or above rated takeoff and 45 hours at or
above rated maximum continuous, respectively, and the declared speed
limits (redlines), as follows:
(i) Prescribe post-event actions or operating limitations
acceptable to the FAA for operation below the declared speed limits
(redlines) and above the CPA speeds.
(ii) If the test required by (b)(2)(ii) of these special conditions
can only be accomplished at a rotor shaft speed lower than the CPA
speed, prescribe post-event actions or operating limitations acceptable
to the FAA for operation below that CPA speed and above the value
demonstrated during the test.
(c) Conduct the endurance test at the incremental cruise thrust
that must be at least equal with the prescribed test required in Sec.
33.87(b)(4). The 25 incremental test cycles must be uniformly
distributed throughout the entire endurance test.
(d) Conduct at least 300 cycles between ground idle and combined
rated takeoff and rated maximum continuous thrust, as follows:
(1) Each cycle to include acceleration to or above rated takeoff
thrust, deceleration from takeoff to ground idle, followed by 5 to 15
seconds at ground idle, acceleration to or above rated
[[Page 53403]]
maximum continuous thrust, and deceleration to ground idle.
(2) The throttle movement from ground idle to rated takeoff or
maximum continuous thrust and from rated takeoff thrust to ground idle
should be not more than one (1) second, except that, if different
regimes of control operations are incorporated necessitating scheduling
of the thrust-control lever motion in going from one extreme position
to the other, a longer period of time is acceptable, but not more than
two (2) seconds. The throttle movement from rated maximum continuous
thrust to ground idle should not be more than five (5) seconds.
(3) The time durations for each cycle associated with either
takeoff or maximum continuous thrust segments must include all maximums
allowed in the TCDS and expected service operation, and must include
the following cycles:
(i) Three (3) cycles of 5 minutes each and one (1) cycle of 10
minutes at the takeoff thrust.
(ii) Three (3) cycles of 30 minutes each at the maximum continuous
thrust.
Issued in Burlington, Massachusetts, on November 8, 2017.
Robert J. Ganley,
Manager, Engine and Propeller Standards Branch, Aircraft Certification
Service.
[FR Doc. 2017-24812 Filed 11-15-17; 8:45 am]
BILLING CODE 4910-13-P
