82_FR_28909 82 FR 28788 - Special Conditions: Safran Aircraft Engines, Silvercrest-2 SC-2D; Rated Takeoff Thrust at High Ambient Temperature

82 FR 28788 - Special Conditions: Safran Aircraft Engines, Silvercrest-2 SC-2D; Rated Takeoff Thrust at High Ambient Temperature

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 121 (June 26, 2017)

Page Range28788-28790
FR Document2017-13305

This action proposes special conditions for the Safran Aircraft Engines (SAE), Silvercrest-2 SC-2D engine model. This engine will have a novel or unusual design feature associated with an additional takeoff rating that increases the exhaust gas temperature (EGT) limit to maintain takeoff thrust in certain high ambient temperature conditions for a maximum accumulated usage of 20 minutes in any one flight. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed 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 82 Issue 121 (Monday, June 26, 2017)
[Federal Register Volume 82, Number 121 (Monday, June 26, 2017)]
[Proposed Rules]
[Pages 28788-28790]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-13305]


========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================


Federal Register / Vol. 82, No. 121 / Monday, June 26, 2017 / 
Proposed Rules

[[Page 28788]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 33

[Docket No. FAA-2017-0586; Notice No. 33-17-01-SC]


Special Conditions: Safran Aircraft Engines, Silvercrest-2 SC-2D; 
Rated Takeoff Thrust at High Ambient Temperature

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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

SUMMARY: This action proposes special conditions for the Safran 
Aircraft Engines (SAE), Silvercrest-2 SC-2D engine model. This engine 
will have a novel or unusual design feature associated with an 
additional takeoff rating that increases the exhaust gas temperature 
(EGT) limit to maintain takeoff thrust in certain high ambient 
temperature conditions for a maximum accumulated usage of 20 minutes in 
any one flight. The applicable airworthiness regulations do not contain 
adequate or appropriate safety standards for this design feature. These 
proposed 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: Send your comments on or before July 6, 2017.
    Certification of the Silvercrest-2 SC-2D engine model is currently 
scheduled for August 2018. The substance of these special conditions 
has been subject to the notice and public comment procedure. Therefore, 
because a delay would significantly affect the applicant's 
certification of the engine, we are shortening the public comment 
period from 45 days to 10 days.

ADDRESSES: Send comments identified by docket number [FAA-2017-0586] 
using any of the following methods:
     Federal eRegulations Portal: Go to http://www.regulations.gov and follow the online instructions for sending your 
comments electronically.
     Mail: Send comments to Docket Operations, M-30, U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery of Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE., Washington, DC, between 8 a.m., and 5 p.m., 
Monday through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: In accordance with 5 U.S.C. 553(c), DOT solicits comments 
from the public to better inform its rulemaking process. DOT posts 
these comments without edit, including any personal information the 
commenter provides, to http://www.regulations.gov, as described in the 
system of records notice (DOT/ALL-14 FDMS), which can be reviewed at 
http://www.transportation.gov/privacy.
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov at any time. Follow the online instructions 
for accessing the docket or go to the Docket Operations Room in W12-140 
of the West Building Ground Floor at 1200 New Jersey Avenue SE., 
Washington, DC, between 9 a.m., and 5 p.m., Monday through Friday, 
except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Tara Fitzgerald, ANE-112, Engine and 
Propeller Directorate, Aircraft Certification Service, 1200 District 
Avenue, Burlington, Massachusetts, 01803-5213; telephone (781) 238-
7130; facsimile (781) 238-7199; email [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite interested persons to participate in this rulemaking by 
submitting written comments, data, or views. The agency also invites 
comments relating to the economic, environmental, energy, or federalism 
impacts that might result from adopting the proposals in this document. 
The most helpful comments reference a specific portion of the proposed 
special conditions, explain the reason for any recommended change, and 
include supporting data. To ensure the docket does not contain 
duplicate comments, commenters should send only one copy of written 
comments, or if comments are filed electronically, commenters should 
submit only one time.
    We will file in the docket all comments we receive, as well as a 
report summarizing each substantive public contact with FAA personnel 
concerning this proposed rulemaking. Before acting on this special 
condition, we will consider all comments we receive on or before the 
closing date for comments. We will consider comments filed after the 
comment period has closed if it is possible to do so without incurring 
expense or delay. We may change these special conditions based on the 
comments we receive.

Background

    On April 19, 2011, SNECMA, now known as SAE, applied for a type 
certificate for the Silvercrest-2 SC-2D engine model. On April 30, 
2014, SAE requested an extension to their original type certificate 
application, which the FAA granted through June 30, 2015. On May 26, 
2015, SAE requested another extension to their type certificate 
application, which the FAA granted through September 30, 2018.
    SAE proposed an additional takeoff rating to maintain takeoff 
thrust in certain high ambient temperature conditions with all engines 
operating (AEO) for the Silvercrest-2 SC-2D engine model. Therefore, 
the Silvercrest-2 SC-2D engine model would have two different takeoff 
ratings. The first rating corresponds with the rated takeoff thrust of 
the engine. The second takeoff rating maintains the takeoff thrust in 
certain high ambient temperature conditions. This additional takeoff 
rating is named ``Rated Takeoff Thrust at High Ambient Temperature'' 
(Rated TOTHAT). The Rated TOTHAT is an approved engine thrust developed 
under specified altitudes and temperatures within the operating 
limitations established for the engine during takeoff operation for a 
maximum usage of 20 minutes in any one flight.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, SAE must show that the Silvercrest-2 SC-2D meets the 
applicable provisions of 14 CFR part 33, as amended by

[[Page 28789]]

Amendments 33-1 through 33-34 in effect on the date of application.
    If the FAA finds that the applicable airworthiness regulations do 
not contain adequate or appropriate safety standards for the 
Silvercrest-2 SC-2D engine model, 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 model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model under Sec.  21.101.
    In addition to complying with the applicable product airworthiness 
regulations and the requirements of the special conditions, the 
Silvercrest-2 SC-2D engine model 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 Silvercrest-2 SC-2D engine model will incorporate a novel or 
unusual design feature, referred to as ``Rated TOTHAT''. This 
additional takeoff rating increases the EGT limit to maintain takeoff 
thrust in certain high ambient temperature conditions for a maximum of 
20 minutes in any one flight.

Discussion

    The Rated TOTHAT is designed for use during takeoff in specified 
high altitudes and high ambient temperature conditions to maintain 
thrust during takeoff for a maximum of 20 minutes in any one flight. 
These proposed special conditions contain additional mandatory post-
flight inspection and maintenance action requirements associated with 
any use of the Rated TOTHAT. These requirements add a rating definition 
in part 1.1 and mandate mandatory inspections in the instructions for 
continued airworthiness (ICA); instructions for installing and 
operating the engine; engine rating and operating limitations; 
instrument connection; and endurance testing.
    The current requirements of the endurance test under Sec.  33.87 
represent a typical airplane flight profile and the severity of the 
takeoff rating. Therefore, the endurance test under Sec.  33.87 covers 
normal, all-engines-operating takeoff conditions for which the engine 
control system limits the engine to the takeoff thrust rating. It is 
intended to represent the airplane flight profile during takeoff under 
specified ambient temperatures for a time until the mandatory 
inspection and maintenance actions can be performed.
    These proposed special conditions require additional test cycles 
that include at least a 150 hours of engine operation as specified in 
Sec.  33.87(a), to demonstrate the engine is capable of performing the 
Rated TOTHAT rating during AEO conditions without disassembly or 
modification.
    The associated engine deterioration, after use of the Rated TOTHAT, 
is not known without the intervening mandatory inspections in these 
special conditions. These mandatory inspections ensure the engine will 
continue to comply with its certification basis, which includes these 
proposed special conditions, after any use of the Rated TOTHAT. The 
applicant is expected to assess the deterioration from use of the Rated 
TOTHAT. The airworthiness limitations section (ALS) must prescribe the 
mandatory post-flight inspections and maintenance actions associated 
with any use of the Rated TOTHAT.
    These requirements maintain a level of safety equivalent to the 
level intended by the applicable airworthiness standards in effect on 
the date of application.

Applicability

    As discussed above, these proposed special conditions are 
applicable to the Silvercrest-2 SC-2D engine model. Should SAE apply at 
a later date for a change to the type certificate to include another 
model incorporating the same novel or unusual design feature, the 
special conditions would apply to that model as well.

Conclusion

    This action affects only the Rated TOTHAT features on the 
Silvercrest-2 SC-2D engine model. It is not a rule of general 
applicability and applies only to SAE, 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, and 44704.

The Proposed Special Conditions

    Accordingly, the FAA proposes, the following special conditions as 
part of the type certification basis for SAE, Silvercrest-2 SC-2D 
engine model.

1. Part 1 Definition

    ``Rated Take-off Thrust at High Ambient Temperature'' (Rated 
TOTHAT) means the approved engine thrust developed under specified 
altitudes and temperatures within the operating limitations established 
for the engine during takeoff operation. Use is limited to two periods, 
no longer than 10 minutes each under one engine inoperative (OEI) 
conditions or 5 minutes each under AEO conditions in any one flight for 
a maximum accumulated usage of 20 minutes in any one flight. Each 
flight where the Rated TOTHAT is used must be followed by mandatory 
inspection and maintenance actions.

2. Part 33 Requirements

    In addition to the airworthiness standards in 14 CFR part 33, 
effective February 1, 1965, amendments 33-1 through 33-34 applicable to 
the engine and the Rated TOTHAT, the following special conditions 
apply:
    (a) Section 33.4, Instructions for Continued Airworthiness.
    (1) The ALS must prescribe the mandatory post-flight inspections 
and maintenance actions associated with any use of the Rated TOTHAT.
    (2) The applicant must validate the adequacy of the inspections and 
maintenance actions required under paragraph 2(a)(1) of these special 
conditions.
    (3) The applicant must establish an in-service engine evaluation 
program to ensure the continued adequacy of the instructions for 
mandatory post-flight inspections and maintenance actions prescribed 
under paragraph 2(a)(1) of these special conditions, and of the data 
for thrust assurance procedures required by paragraph 2(b)(2) of these 
special conditions. The program must include service engine tests or 
equivalent service engine test experience on engines of similar design 
and evaluations of service usage of the Rated TOTHAT.
    (b) Section 33.5, Instruction manual for installing and operating 
the engine.
    (1) Installation Instructions:
    (i) The applicant must identify the means, or provisions for means, 
provided in compliance with the requirements of paragraph 2(e) of these 
special conditions.
    (ii) The applicant must specify that the engine thrust control 
system automatically resets the thrust on the operating engine to the 
Rated TOTHAT level when one engine fails during

[[Page 28790]]

takeoff at specified altitudes and temperatures.
    (iii) The applicant must specify that the Rated TOTHAT is available 
by manual crew selection at specified altitudes and temperatures in AEO 
conditions.
    (2) Operating Instructions: The applicant must provide data on 
engine performance characteristics and variability to enable the 
airplane manufacturer to establish airplane thrust assurance 
procedures.
    (c) Section 33.7, Engine ratings and operating limitations.
    (1) Rated TOTHAT and the associated operating limitations are 
established as follows:
    (i) The thrust is the same as the engine takeoff rated thrust with 
extended flat rating corner point.
    (ii) The rotational speed limits are the same as those associated 
with the engine takeoff rated thrust.
    (iii) The applicant must establish a gas temperature steady-state 
limit and, if necessary, a transient gas over temperature limit for 
which the duration is no longer than 30 seconds.
    (iv) The use is limited to two periods of no longer than 10 minutes 
each under OEI conditions or 5 minutes each under AEO conditions in any 
one flight, for a maximum accumulated usage of 20 minutes in any one 
flight. Each flight where the Rated TOTHAT is used must be followed by 
mandatory inspections and maintenance actions prescribed by paragraph 
2(a)(1) of these special conditions.
    (2) The applicant must propose language to include in the type 
certificate data sheet specified in Sec.  21.41 for the following:
    (i) Rated TOTHAT and associated limitations.
    (ii) As required by Sec.  33.5(b), Operating instructions, include 
a note stating that ``Rated Takeoff Thrust at High Ambient Temperature 
(Rated TOTHAT) means the approved engine thrust developed under 
specified altitudes and temperatures within the operating limitations 
established for the engine. Use is limited to two periods, no longer 
than 10 minutes each under OEI conditions or 5 minutes each under AEO 
conditions in any one flight, for a maximum accumulated usage of 20 
minutes in any one flight. Each flight where the Rated TOTHAT is used 
must be followed by mandatory inspection and maintenance actions.''
    (iii) As required by Sec.  33.5(b), Operating instructions, include 
a note stating that the engine thrust control system automatically 
resets the thrust on the operating engine to the Rated TOTHAT level 
when one engine fails during takeoff at specified altitudes and 
temperatures, and the Rated TOTHAT is available by manual selection 
when all engines are operational during takeoff at specified altitudes 
and temperatures.
    (d) Section 33.28, Engine Control Systems.
    The engine must incorporate a means, or a provision for a means, 
for automatic availability and automatic control of the Rated TOTHAT 
under OEI conditions and must permit manual activation of the Rated 
TOTHAT under AEO conditions.
    (e) Section 33.29, Instrument connection.
    The engine must:
    (1) Have means, or provisions for means, to alert the pilot when 
the Rated TOTHAT is in use, when the event begins and when the time 
interval expires.
    (2) Have means, or provision for means, which cannot be reset in 
flight, to:
    (i) Automatically record each use and duration of the Rated TOTHAT, 
and
    (ii) Alert maintenance personnel that the engine has been operated 
at the Rated TOTHAT and permit retrieval of recorded data.
    (3) Have means, or provision for means, to enable routine 
verification of the proper operation of the means in paragraph 2(e)(1) 
and (e)(2) of these special conditions.
    (f) Section 33.85(b), Calibration tests.
    The applicant must base the calibration test on the thrust check at 
the end of the endurance test required by Sec.  33.87 of these special 
conditions.
    (g) Section 33.87, Endurance test.
    (1) In addition to the applicable requirements of Sec.  33.87(a):
    (i) The Sec.  33.87 endurance test must be modified as follows:
    (A) Modify the thirty minute test cycle at the rated takeoff thrust 
in Sec.  33.87(b)(2)(ii) to run one minute at rated takeoff thrust, 
followed by five minutes at the Rated TOTHAT, followed by the rated 
takeoff thrust for the remaining twenty-four minutes.
    (B) The modified thirty minute period described above in paragraph 
2(g)(1)(i)(A) must be repeated ten times in cycles 16 through 25 of the 
Sec.  33.87 endurance test.
    (2) After completion of the tests required by Sec.  33.87(b), as 
modified in paragraph 2(g)(1)(i) above, and without intervening 
disassembly, except as needed to replace those parts described as 
consumables in the ICA, the applicant must conduct the following test 
sequence for a total time of not less than 120 minutes:
    (i) Ten minutes at Rated TOTHAT.
    (ii) Eighty-eight minutes at rated maximum continuous thrust.
    (iii) One minute at 50 percent of rated takeoff thrust.
    (iv) Ten minutes at Rated TOTHAT.
    (v) Ten minutes at rated maximum continuous thrust.
    (vi) One minute at flight idle.
    (3) The test sequence of Sec. Sec.  33.87(b)(1) through (b)(6) of 
these special conditions must be run continuously. If a stop occurs 
during these tests, the interrupted sequence must be repeated unless 
the applicant shows that the severity of the test would not be reduced 
if the current tests were continued.
    (4) Where the engine characteristics are such that acceleration to 
the Rated TOTHAT results in a transient over temperature in excess of 
the steady-state temperature limit identified in paragraph 2(c)(1)(iii) 
of these special conditions, the transient gas overtemperature must be 
applied to each acceleration to the Rated TOTHAT of the test sequence 
in paragraph 2(g)(2) of these special conditions.
    (h) Section 33.93, Teardown inspection.
    The applicant must perform the teardown inspection required by 
Sec.  33.93(a), after completing the endurance test prescribed by Sec.  
33.87 of these special conditions.
    (i) Section 33.201, Design and test requirements for Early ETOPS 
eligibility.
    In addition to the requirements of Sec.  33.201(c)(1), the 
simulated ETOPS mission cyclic endurance test must include two cycles 
of 10 minute duration, each at the Rated TOTHAT; one before the last 
diversion cycle and one at the end of the ETOPS test.

    Issued in Burlington, Massachusetts, on June 14, 2017.
Carlos A. Pestana,
Acting Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2017-13305 Filed 6-23-17; 8:45 am]
 BILLING CODE 4910-13-P



                                                  28788

                                                  Proposed Rules                                                                                                 Federal Register
                                                                                                                                                                 Vol. 82, No. 121

                                                                                                                                                                 Monday, June 26, 2017



                                                  This section of the FEDERAL REGISTER                      • Federal eRegulations Portal: Go to                 recommended change, and include
                                                  contains notices to the public of the proposed          http://www.regulations.gov and follow                  supporting data. To ensure the docket
                                                  issuance of rules and regulations. The                  the online instructions for sending your               does not contain duplicate comments,
                                                  purpose of these notices is to give interested          comments electronically.                               commenters should send only one copy
                                                  persons an opportunity to participate in the              • Mail: Send comments to Docket                      of written comments, or if comments are
                                                  rule making prior to the adoption of the final
                                                                                                          Operations, M–30, U.S. Department of                   filed electronically, commenters should
                                                  rules.
                                                                                                          Transportation (DOT), 1200 New Jersey                  submit only one time.
                                                                                                          Avenue SE., Room W12–140, West                            We will file in the docket all
                                                  DEPARTMENT OF TRANSPORTATION                            Building Ground Floor, Washington, DC                  comments we receive, as well as a
                                                                                                          20590–0001.                                            report summarizing each substantive
                                                  Federal Aviation Administration                           • Hand Delivery of Courier: Take                     public contact with FAA personnel
                                                                                                          comments to Docket Operations in                       concerning this proposed rulemaking.
                                                  14 CFR Part 33                                          Room W12–140 of the West Building                      Before acting on this special condition,
                                                                                                          Ground Floor at 1200 New Jersey                        we will consider all comments we
                                                                                                          Avenue SE., Washington, DC, between 8                  receive on or before the closing date for
                                                  [Docket No. FAA–2017–0586; Notice No. 33–
                                                  17–01–SC]                                               a.m., and 5 p.m., Monday through                       comments. We will consider comments
                                                                                                          Friday, except Federal holidays.                       filed after the comment period has
                                                  Special Conditions: Safran Aircraft                       • Fax: Fax comments to Docket                        closed if it is possible to do so without
                                                  Engines, Silvercrest-2 SC–2D; Rated                     Operations at 202–493–2251.                            incurring expense or delay. We may
                                                  Takeoff Thrust at High Ambient                            Privacy: In accordance with 5 U.S.C.                 change these special conditions based
                                                  Temperature                                             553(c), DOT solicits comments from the                 on the comments we receive.
                                                                                                          public to better inform its rulemaking                 Background
                                                  AGENCY: Federal Aviation                                process. DOT posts these comments
                                                  Administration (FAA), DOT.                              without edit, including any personal                      On April 19, 2011, SNECMA, now
                                                  ACTION: Notice of proposed special                      information the commenter provides, to                 known as SAE, applied for a type
                                                  conditions.                                             http://www.regulations.gov, as                         certificate for the Silvercrest-2 SC–2D
                                                                                                          described in the system of records                     engine model. On April 30, 2014, SAE
                                                  SUMMARY:   This action proposes special                 notice (DOT/ALL–14 FDMS), which can                    requested an extension to their original
                                                  conditions for the Safran Aircraft                      be reviewed at http://                                 type certificate application, which the
                                                  Engines (SAE), Silvercrest-2 SC–2D                      www.transportation.gov/privacy.                        FAA granted through June 30, 2015. On
                                                  engine model. This engine will have a                     Docket: Background documents or                      May 26, 2015, SAE requested another
                                                  novel or unusual design feature                         comments received may be read at                       extension to their type certificate
                                                  associated with an additional takeoff                   http://www.regulations.gov at any time.                application, which the FAA granted
                                                  rating that increases the exhaust gas                   Follow the online instructions for                     through September 30, 2018.
                                                  temperature (EGT) limit to maintain                     accessing the docket or go to the Docket                  SAE proposed an additional takeoff
                                                  takeoff thrust in certain high ambient                                                                         rating to maintain takeoff thrust in
                                                                                                          Operations Room in W12–140 of the
                                                  temperature conditions for a maximum                                                                           certain high ambient temperature
                                                                                                          West Building Ground Floor at 1200
                                                  accumulated usage of 20 minutes in any                                                                         conditions with all engines operating
                                                                                                          New Jersey Avenue SE., Washington,
                                                  one flight. The applicable airworthiness                                                                       (AEO) for the Silvercrest-2 SC–2D
                                                                                                          DC, between 9 a.m., and 5 p.m., Monday
                                                  regulations do not contain adequate or                                                                         engine model. Therefore, the
                                                                                                          through Friday, except Federal holidays.
                                                  appropriate safety standards for this                                                                          Silvercrest-2 SC–2D engine model
                                                                                                          FOR FURTHER INFORMATION CONTACT: Tara                  would have two different takeoff ratings.
                                                  design feature. These proposed special                  Fitzgerald, ANE–112, Engine and
                                                  conditions contain the additional safety                                                                       The first rating corresponds with the
                                                                                                          Propeller Directorate, Aircraft                        rated takeoff thrust of the engine. The
                                                  standards that the Administrator                        Certification Service, 1200 District
                                                  considers necessary to establish a level                                                                       second takeoff rating maintains the
                                                                                                          Avenue, Burlington, Massachusetts,                     takeoff thrust in certain high ambient
                                                  of safety equivalent to that established                01803–5213; telephone (781) 238–7130;
                                                  by the existing airworthiness standards.                                                                       temperature conditions. This additional
                                                                                                          facsimile (781) 238–7199; email                        takeoff rating is named ‘‘Rated Takeoff
                                                  DATES: Send your comments on or                         Tara.Fitzgerald@faa.gov.                               Thrust at High Ambient Temperature’’
                                                  before July 6, 2017.                                    SUPPLEMENTARY INFORMATION:                             (Rated TOTHAT). The Rated TOTHAT
                                                    Certification of the Silvercrest-2 SC–                                                                       is an approved engine thrust developed
                                                  2D engine model is currently scheduled                  Comments Invited
                                                                                                                                                                 under specified altitudes and
                                                  for August 2018. The substance of these                   We invite interested persons to                      temperatures within the operating
                                                  special conditions has been subject to                  participate in this rulemaking by                      limitations established for the engine
                                                  the notice and public comment                           submitting written comments, data, or
sradovich on DSK3GMQ082PROD with PROPOSALS




                                                                                                                                                                 during takeoff operation for a maximum
                                                  procedure. Therefore, because a delay                   views. The agency also invites                         usage of 20 minutes in any one flight.
                                                  would significantly affect the                          comments relating to the economic,
                                                  applicant’s certification of the engine,                environmental, energy, or federalism                   Type Certification Basis
                                                  we are shortening the public comment                    impacts that might result from adopting                  Under the provisions of Title 14, Code
                                                  period from 45 days to 10 days.                         the proposals in this document. The                    of Federal Regulations (14 CFR) 21.17,
                                                  ADDRESSES: Send comments identified                     most helpful comments reference a                      SAE must show that the Silvercrest-2
                                                  by docket number [FAA–2017–0586]                        specific portion of the proposed special               SC–2D meets the applicable provisions
                                                  using any of the following methods:                     conditions, explain the reason for any                 of 14 CFR part 33, as amended by


                                             VerDate Sep<11>2014   16:14 Jun 23, 2017   Jkt 241001   PO 00000   Frm 00001   Fmt 4702   Sfmt 4702   E:\FR\FM\26JNP1.SGM   26JNP1


                                                                           Federal Register / Vol. 82, No. 121 / Monday, June 26, 2017 / Proposed Rules                                            28789

                                                  Amendments 33–1 through 33–34 in                        system limits the engine to the takeoff                the type certification basis for SAE,
                                                  effect on the date of application.                      thrust rating. It is intended to represent             Silvercrest-2 SC–2D engine model.
                                                     If the FAA finds that the applicable                 the airplane flight profile during takeoff
                                                  airworthiness regulations do not contain                                                                       1. Part 1 Definition
                                                                                                          under specified ambient temperatures
                                                  adequate or appropriate safety standards                for a time until the mandatory                            ‘‘Rated Take-off Thrust at High
                                                  for the Silvercrest-2 SC–2D engine                      inspection and maintenance actions can                 Ambient Temperature’’ (Rated
                                                  model, because of a novel or unusual                    be performed.                                          TOTHAT) means the approved engine
                                                  design feature, special conditions are                     These proposed special conditions                   thrust developed under specified
                                                  prescribed under the provisions of                      require additional test cycles that                    altitudes and temperatures within the
                                                  § 21.16.                                                include at least a 150 hours of engine                 operating limitations established for the
                                                     Special conditions are initially                     operation as specified in § 33.87(a), to               engine during takeoff operation. Use is
                                                  applicable to the model for which they                  demonstrate the engine is capable of                   limited to two periods, no longer than
                                                  are issued. Should the type certificate                 performing the Rated TOTHAT rating                     10 minutes each under one engine
                                                  for that model be amended later to                      during AEO conditions without                          inoperative (OEI) conditions or 5
                                                  include any other model that                            disassembly or modification.                           minutes each under AEO conditions in
                                                  incorporates the same or similar novel                     The associated engine deterioration,                any one flight for a maximum
                                                  or unusual design feature, the special                  after use of the Rated TOTHAT, is not                  accumulated usage of 20 minutes in any
                                                  conditions would also apply to the other                known without the intervening                          one flight. Each flight where the Rated
                                                  model under § 21.101.                                   mandatory inspections in these special                 TOTHAT is used must be followed by
                                                     In addition to complying with the                    conditions. These mandatory                            mandatory inspection and maintenance
                                                  applicable product airworthiness                        inspections ensure the engine will                     actions.
                                                  regulations and the requirements of the                 continue to comply with its certification
                                                  special conditions, the Silvercrest-2 SC–               basis, which includes these proposed                   2. Part 33 Requirements
                                                  2D engine model must comply with the                    special conditions, after any use of the                 In addition to the airworthiness
                                                  fuel venting and exhaust emission                       Rated TOTHAT. The applicant is                         standards in 14 CFR part 33, effective
                                                  requirements of 14 CFR part 34.                         expected to assess the deterioration                   February 1, 1965, amendments 33–1
                                                     The FAA issues special conditions, as                from use of the Rated TOTHAT. The                      through 33–34 applicable to the engine
                                                  defined in 14 CFR 11.19, in accordance                  airworthiness limitations section (ALS)                and the Rated TOTHAT, the following
                                                  with § 11.38, and they become part of                   must prescribe the mandatory post-                     special conditions apply:
                                                  the type certification basis under                      flight inspections and maintenance                       (a) Section 33.4, Instructions for
                                                  § 21.17(a)(2).                                          actions associated with any use of the                 Continued Airworthiness.
                                                  Novel or Unusual Design Features                        Rated TOTHAT.                                            (1) The ALS must prescribe the
                                                                                                             These requirements maintain a level                 mandatory post-flight inspections and
                                                     The Silvercrest-2 SC–2D engine                       of safety equivalent to the level                      maintenance actions associated with
                                                  model will incorporate a novel or                       intended by the applicable                             any use of the Rated TOTHAT.
                                                  unusual design feature, referred to as                  airworthiness standards in effect on the                 (2) The applicant must validate the
                                                  ‘‘Rated TOTHAT’’. This additional                       date of application.                                   adequacy of the inspections and
                                                  takeoff rating increases the EGT limit to
                                                                                                          Applicability                                          maintenance actions required under
                                                  maintain takeoff thrust in certain high
                                                                                                                                                                 paragraph 2(a)(1) of these special
                                                  ambient temperature conditions for a                      As discussed above, these proposed
                                                                                                                                                                 conditions.
                                                  maximum of 20 minutes in any one                        special conditions are applicable to the
                                                  flight.                                                                                                          (3) The applicant must establish an
                                                                                                          Silvercrest-2 SC–2D engine model.
                                                                                                                                                                 in-service engine evaluation program to
                                                  Discussion                                              Should SAE apply at a later date for a
                                                                                                                                                                 ensure the continued adequacy of the
                                                                                                          change to the type certificate to include
                                                     The Rated TOTHAT is designed for                                                                            instructions for mandatory post-flight
                                                                                                          another model incorporating the same
                                                  use during takeoff in specified high                                                                           inspections and maintenance actions
                                                                                                          novel or unusual design feature, the
                                                  altitudes and high ambient temperature                                                                         prescribed under paragraph 2(a)(1) of
                                                                                                          special conditions would apply to that
                                                  conditions to maintain thrust during                                                                           these special conditions, and of the data
                                                                                                          model as well.
                                                  takeoff for a maximum of 20 minutes in                                                                         for thrust assurance procedures required
                                                  any one flight. These proposed special                  Conclusion                                             by paragraph 2(b)(2) of these special
                                                  conditions contain additional                             This action affects only the Rated                   conditions. The program must include
                                                  mandatory post-flight inspection and                    TOTHAT features on the Silvercrest-2                   service engine tests or equivalent
                                                  maintenance action requirements                         SC–2D engine model. It is not a rule of                service engine test experience on
                                                  associated with any use of the Rated                    general applicability and applies only to              engines of similar design and
                                                  TOTHAT. These requirements add a                        SAE, who requested FAA approval of                     evaluations of service usage of the Rated
                                                  rating definition in part 1.1 and                       this engine feature.                                   TOTHAT.
                                                  mandate mandatory inspections in the                                                                             (b) Section 33.5, Instruction manual
                                                                                                          List of Subjects in 14 CFR Part 33                     for installing and operating the engine.
                                                  instructions for continued airworthiness
                                                  (ICA); instructions for installing and                    Aircraft, Engines, Aviation safety,                    (1) Installation Instructions:
                                                  operating the engine; engine rating and                 Reporting and recordkeeping                              (i) The applicant must identify the
                                                  operating limitations; instrument                       requirements.                                          means, or provisions for means,
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                                                  connection; and endurance testing.                        The authority citation for these                     provided in compliance with the
                                                     The current requirements of the                      special conditions is as follows:                      requirements of paragraph 2(e) of these
                                                  endurance test under § 33.87 represent a                  Authority: 49 U.S.C. 106(g), 40113, 44701,           special conditions.
                                                  typical airplane flight profile and the                 44702, and 44704.                                        (ii) The applicant must specify that
                                                  severity of the takeoff rating. Therefore,                                                                     the engine thrust control system
                                                  the endurance test under § 33.87 covers                 The Proposed Special Conditions                        automatically resets the thrust on the
                                                  normal, all-engines-operating takeoff                     Accordingly, the FAA proposes, the                   operating engine to the Rated TOTHAT
                                                  conditions for which the engine control                 following special conditions as part of                level when one engine fails during


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                                                  28790                    Federal Register / Vol. 82, No. 121 / Monday, June 26, 2017 / Proposed Rules

                                                  takeoff at specified altitudes and                      during takeoff at specified altitudes and                 (iii) One minute at 50 percent of rated
                                                  temperatures.                                           temperatures, and the Rated TOTHAT is                  takeoff thrust.
                                                     (iii) The applicant must specify that                available by manual selection when all                    (iv) Ten minutes at Rated TOTHAT.
                                                  the Rated TOTHAT is available by                        engines are operational during takeoff at                 (v) Ten minutes at rated maximum
                                                  manual crew selection at specified                      specified altitudes and temperatures.                  continuous thrust.
                                                  altitudes and temperatures in AEO                         (d) Section 33.28, Engine Control                       (vi) One minute at flight idle.
                                                  conditions.                                             Systems.                                                  (3) The test sequence of §§ 33.87(b)(1)
                                                     (2) Operating Instructions: The                        The engine must incorporate a means,                 through (b)(6) of these special
                                                  applicant must provide data on engine                   or a provision for a means, for automatic              conditions must be run continuously. If
                                                  performance characteristics and                         availability and automatic control of the              a stop occurs during these tests, the
                                                  variability to enable the airplane                      Rated TOTHAT under OEI conditions                      interrupted sequence must be repeated
                                                  manufacturer to establish airplane                      and must permit manual activation of                   unless the applicant shows that the
                                                  thrust assurance procedures.                            the Rated TOTHAT under AEO                             severity of the test would not be
                                                     (c) Section 33.7, Engine ratings and                 conditions.                                            reduced if the current tests were
                                                  operating limitations.                                    (e) Section 33.29, Instrument                        continued.
                                                     (1) Rated TOTHAT and the associated                  connection.                                               (4) Where the engine characteristics
                                                  operating limitations are established as                  The engine must:                                     are such that acceleration to the Rated
                                                  follows:                                                  (1) Have means, or provisions for                    TOTHAT results in a transient over
                                                     (i) The thrust is the same as the                    means, to alert the pilot when the Rated               temperature in excess of the steady-state
                                                  engine takeoff rated thrust with                        TOTHAT is in use, when the event                       temperature limit identified in
                                                  extended flat rating corner point.                      begins and when the time interval                      paragraph 2(c)(1)(iii) of these special
                                                     (ii) The rotational speed limits are the             expires.                                               conditions, the transient gas
                                                  same as those associated with the                         (2) Have means, or provision for                     overtemperature must be applied to
                                                  engine takeoff rated thrust.                            means, which cannot be reset in flight,                each acceleration to the Rated TOTHAT
                                                     (iii) The applicant must establish a                 to:                                                    of the test sequence in paragraph 2(g)(2)
                                                  gas temperature steady-state limit and, if                (i) Automatically record each use and                of these special conditions.
                                                  necessary, a transient gas over                         duration of the Rated TOTHAT, and                         (h) Section 33.93, Teardown
                                                  temperature limit for which the                           (ii) Alert maintenance personnel that                inspection.
                                                  duration is no longer than 30 seconds.                  the engine has been operated at the                       The applicant must perform the
                                                     (iv) The use is limited to two periods               Rated TOTHAT and permit retrieval of                   teardown inspection required by
                                                  of no longer than 10 minutes each under                 recorded data.                                         § 33.93(a), after completing the
                                                  OEI conditions or 5 minutes each under                    (3) Have means, or provision for                     endurance test prescribed by § 33.87 of
                                                  AEO conditions in any one flight, for a                 means, to enable routine verification of               these special conditions.
                                                  maximum accumulated usage of 20                         the proper operation of the means in                      (i) Section 33.201, Design and test
                                                  minutes in any one flight. Each flight                  paragraph 2(e)(1) and (e)(2) of these                  requirements for Early ETOPS
                                                  where the Rated TOTHAT is used must                     special conditions.                                    eligibility.
                                                                                                            (f) Section 33.85(b), Calibration tests.                In addition to the requirements of
                                                  be followed by mandatory inspections                      The applicant must base the
                                                  and maintenance actions prescribed by                                                                          § 33.201(c)(1), the simulated ETOPS
                                                                                                          calibration test on the thrust check at                mission cyclic endurance test must
                                                  paragraph 2(a)(1) of these special                      the end of the endurance test required
                                                  conditions.                                                                                                    include two cycles of 10 minute
                                                                                                          by § 33.87 of these special conditions.                duration, each at the Rated TOTHAT;
                                                     (2) The applicant must propose                         (g) Section 33.87, Endurance test.
                                                  language to include in the type                                                                                one before the last diversion cycle and
                                                                                                            (1) In addition to the applicable                    one at the end of the ETOPS test.
                                                  certificate data sheet specified in § 21.41             requirements of § 33.87(a):
                                                  for the following:                                        (i) The § 33.87 endurance test must be                 Issued in Burlington, Massachusetts, on
                                                     (i) Rated TOTHAT and associated                      modified as follows:                                   June 14, 2017.
                                                  limitations.                                              (A) Modify the thirty minute test                    Carlos A. Pestana,
                                                     (ii) As required by § 33.5(b), Operating             cycle at the rated takeoff thrust in                   Acting Assistant Manager, Engine and
                                                  instructions, include a note stating that               § 33.87(b)(2)(ii) to run one minute at                 Propeller Directorate, Aircraft Certification
                                                  ‘‘Rated Takeoff Thrust at High Ambient                  rated takeoff thrust, followed by five                 Service.
                                                  Temperature (Rated TOTHAT) means                        minutes at the Rated TOTHAT, followed                  [FR Doc. 2017–13305 Filed 6–23–17; 8:45 am]
                                                  the approved engine thrust developed                    by the rated takeoff thrust for the                    BILLING CODE 4910–13–P
                                                  under specified altitudes and                           remaining twenty-four minutes.
                                                  temperatures within the operating                         (B) The modified thirty minute period
                                                  limitations established for the engine.                 described above in paragraph                           DEPARTMENT OF TRANSPORTATION
                                                  Use is limited to two periods, no longer                2(g)(1)(i)(A) must be repeated ten times
                                                  than 10 minutes each under OEI                                                                                 Federal Aviation Administration
                                                                                                          in cycles 16 through 25 of the § 33.87
                                                  conditions or 5 minutes each under                      endurance test.
                                                  AEO conditions in any one flight, for a                   (2) After completion of the tests                    14 CFR Part 33
                                                  maximum accumulated usage of 20                         required by § 33.87(b), as modified in                 [Docket No. FAA–2017–0537; Notice No. 33–
                                                  minutes in any one flight. Each flight                  paragraph 2(g)(1)(i) above, and without                17–02–SC]
                                                  where the Rated TOTHAT is used must                     intervening disassembly, except as
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                                                  be followed by mandatory inspection                     needed to replace those parts described                Special Conditions: General Electric
                                                  and maintenance actions.’’                              as consumables in the ICA, the                         Company, GE9X Engine Models;
                                                     (iii) As required by § 33.5(b),                      applicant must conduct the following                   Endurance Test Special Conditions
                                                  Operating instructions, include a note                  test sequence for a total time of not less             AGENCY: Federal Aviation
                                                  stating that the engine thrust control                  than 120 minutes:                                      Administration (FAA), DOT.
                                                  system automatically resets the thrust                    (i) Ten minutes at Rated TOTHAT.                     ACTION: Notice of proposed special
                                                  on the operating engine to the Rated                      (ii) Eighty-eight minutes at rated
                                                                                                                                                                 conditions.
                                                  TOTHAT level when one engine fails                      maximum continuous thrust.


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Document Created: 2018-11-14 10:11:38
Document Modified: 2018-11-14 10:11:38
CategoryRegulatory Information
CollectionFederal Register
sudoc ClassAE 2.7:
GS 4.107:
AE 2.106:
PublisherOffice of the Federal Register, National Archives and Records Administration
SectionProposed Rules
ActionNotice of proposed special conditions.
DatesSend your comments on or before July 6, 2017.
ContactTara Fitzgerald, ANE-112, Engine and Propeller Directorate, Aircraft Certification Service, 1200 District Avenue, Burlington, Massachusetts, 01803-5213; telephone (781) 238- 7130; facsimile (781) 238-7199; email [email protected]
FR Citation82 FR 28788 
CFR AssociatedAircraft; Engines; Aviation Safety and Reporting and Recordkeeping Requirements

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