[Federal Register Volume 73, Number 59 (Wednesday, March 26, 2008)]
[Proposed Rules]
[Pages 15955-15959]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-6148]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Parts 1 and 33
[Docket No. 2007-28502; Notice No. 07-09]
RIN No. 2120-AJ06
Airworthiness Standards; Aircraft Engine Standards Overtorque
Limits
AGENCY: Federal Aviation Administration (FAA) DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to amend the certification standards for
aircraft engines to introduce requirements for approval of maximum
engine overtorque. This action would add a new engine overtorque test,
amend engine ratings and operating limitations, and define maximum
engine overtorque for certain turbopropeller and turboshaft engines.
The proposed rule is intended to harmonize applicable U.S. and European
standards and simplify airworthiness approvals for import and export of
aircraft engines.
[[Page 15956]]
DATES: Send your comments on or before June 24, 2008.
ADDRESSES: You may send comments identified by Docket Number FAA-2007-
28502 using any of the following methods:
Federal eRulemaking Portal: Go to: http://www.regulations.gov and follow the online instructions for sending your
comments electronically.
Mail: Send comments to Docket Operations, U.S. Department
of Transportation, 1200 New Jersey Avenue, SE., West Building Ground
Floor, Room W12-140, Washington, DC 20590-0001.
Hand Delivery or Courier: Bring comments to Docket
Operations in Room 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.
Fax: Fax comments to the Docket Operations at 202-493-
2251.
For more information on the rulemaking process, see the
SUPPLEMENTARY INFORMATION section of this document.
Privacy: We will post all comments we receive, without change, to
http://www.regulations.gov, including any personal information you
provide. Using the search function of our docket web site, anyone can
find and read the electronic form of all comments received into any of
our dockets, including the name of the individual sending the comment
(or signing the comment for an association, business, labor union,
etc.). You may review DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78) or you
may visit http://DocketsInfo.dot.gov.
Docket: To read background documents or comments received, go to:
http://www.regulations.gov at any time and follow the online
instructions for accessing the docket; or, go to the Docket Operations
in Room 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: For technical questions concerning
this proposed rule contact Tim Mouzakis, Engine and Propeller
Directorate, Standards Staff, ANE-110, Federal Aviation Administration
(FAA), New England Region, 12 New England Executive Park, Burlington,
Massachusetts 01803; telephone (781) 238-7114; facsimile (781) 238-
7199; electronic mail ``[email protected]''. For legal
questions concerning this proposed rule contact Vincent Bennett,
Federal Aviation Administration, Office of Regional Counsel (ANE-7),
New England Region, 12 New England Executive Park, Room 311,
Burlington, MA 01803; telephone (781) 238-7044; facsimile (781) 238-
7055; electronic mail [email protected].
SUPPLEMENTARY INFORMATION: Later in this preamble under the Additional
Information section, we discuss how you can comment on this proposal
and how we will handle your comments. Included in this discussion is
related information about the docket, privacy, and the handling of
proprietary or confidential business information. We also discuss how
you can get a copy of this proposal and related rulemaking documents.
Authority for This Rulemaking
The FAA's authority to issue rules on aviation safety is found in
Title 49 of the United States Code. Subtitle I, Section 106 describes
the authority of the FAA Administrator. Subtitle VII, Aviation
Programs, describes in more detail the scope of the agency's authority.
This rulemaking is promulgated under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, ``General
requirements.'' Under that section, the FAA is charged with prescribing
regulations for promoting safe flight of civil aircraft in air commerce
by prescribing regulations for practices, methods, and procedures the
Administrator finds necessary for safety in air commerce, including
minimum safety standards for aircraft engines. This regulation is
within the scope of that authority because it updates the existing
regulations for aircraft engine standards overtorque limits.
Background
Part 33 of Title 14, Code of Federal Regulations (14 CFR part 33)
prescribes airworthiness standards for original and amended type
certificates for aircraft engines. The European Aviation Safety Agency
(EASA) Certification Specification--Engines (CS-E) prescribes
corresponding airworthiness standards for the certification of aircraft
engines in Europe. While part 33 and the CS-E are similar, they differ
in several respects. For applicants seeking certification under part 33
and CS-E, these differences result in additional costs and delays in
the time required for certification. In addition, because the CS-E does
contain specific standards for the approval of maximum overtorque
limits, U.S. aircraft engine manufacturers face additional costs when
seeking certification of their engine designs by the JAA/EASA for
export.
Currently, part 33 does not contain explicit standards for a
maximum engine overtorque limit. Engine manufacturers apply for and
obtain FAA approvals of maximum overtorque limits based on the results
of certification engine tests and analysis that did not directly
address considerations for maximum overtorque limits.
The FAA tasked the Aviation Rulemaking Advisory Committee
(ARAC),\1\ through its Engine Harmonization Working Group (EHWG), to
provide advice and recommendations on proposed standards for engine
overtorque. This proposed rule is based on ARAC's recommendations to
the FAA.
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\1\ Published in the Federal Register, October 20, 1998 (63 FR
56059).
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General Discussion of the Proposed Rule
The proposed rule would establish a standard for applicants to use
in applying for and obtaining approval of a maximum overtorque limit.
The proposed rule would harmonize U.S. and European standards for
approving engine overtorque transients for turbopropeller and
turboshaft engines with free power-turbines. The proposed rule would
not permit an overtorque limit for these engines when operating at the
30-second and 2-minute one engine inoperative (OEI) ratings.
This proposed rule addresses a condition that can occur on
turbopropeller and turboshaft engines with free power turbines. Sudden
changes in the rotorcraft/aircraft blade pitch or power demand, such as
an engine failure on a twin engine rotorcraft, can cause a significant
decrease in the rotor/propeller speed. For a rotorcraft engine,
overtorque conditions may occur during the period the engine is
accelerating the rotor system back to normal operating speeds. This
NPRM proposes requirements to establish a maximum transient (20 seconds
maximum) overtorque limit.
The torque transmitting components in a free turbine engine are
typically the turbine blades, disks, shafts, and gears (if an internal
gearbox exists). Torque has differing effects on the stress levels in
these components. For example, the stresses in turbine blades and disks
are dominated by centrifugal loads and, to a lesser extent, by
temperature. The effects of gas loads producing torque have a minor
effect on total stress in these components. The stress levels of
components, such as shafts and gears,
[[Page 15957]]
are typically dominated by the amount of torque they are transmitting.
Turbine entry temperatures generally have little effect on the stress
levels in shafts and gears. Typically, the time spent at maximum steady
state temperature and high speed during the endurance test (required by
Sec. 33.87) results in higher turbine blade and disk stresses than
would occur during a maximum overtorque event. Therefore, when the
evidence of the endurance tests can be used to provide the
substantiation required during certification, the requirement to run
the overtorque test at maximum steady state temperature may be adjusted
by other relevant factors.
Paperwork Reduction Act
The Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)) requires
that the FAA consider the impact of paperwork and other information
collection burdens imposed on the public. We have determined that there
is no new information collection requirements associated with this
proposed rule.
International Compatibility
In keeping with U.S. obligations under the Convention on
International Civil Aviation, it is FAA policy to comply with
International Civil Aviation Organization (ICAO) Standards and
Recommended Practices to the maximum extent practicable. The FAA has
determined that there are no ICAO Standards and Recommended Practices
that correspond to these proposed regulations.
Regulatory Evaluation, Regulatory Flexibility Determination,
International Trade Impact Assessment, and Unfunded Mandates Assessment
Changes to Federal regulations must undergo several economic
analyses. First, Executive Order 12866 directs that each Federal agency
shall propose or adopt a regulation only upon a reasoned determination
that the benefits of the intended regulation justify its costs. Second,
the Regulatory Flexibility Act of 1980 (Pub. L. 96-354) requires
agencies to analyze the economic impact of regulatory changes on small
entities. Third, the Trade Agreements Act (Pub. L. 96-39) prohibits
agencies from setting standards that create unnecessary obstacles to
the foreign commerce of the United States. In developing U.S.
standards, the Trade Act requires agencies to consider international
standards and, where appropriate, that they be the basis of U.S.
standards. Fourth, the Unfunded Mandates Reform Act of 1995 (Pub. L.
104-4) requires agencies to prepare a written assessment of the costs,
benefits, and other effects of proposed or final rules that include a
Federal mandate likely to result in the expenditure by State, local, or
tribal governments, in the aggregate, or by the private sector, of $100
million or more annually (adjusted for inflation with base year of
1995). This portion of the preamble summarizes the FAA's analysis of
the economic impacts of this proposed rule.
Department of Transportation Order DOT 2100.5 prescribes policies
and procedures for simplification, analysis, and review of regulations.
If the expected cost impact is so minimal that a proposed or final rule
does not warrant a full evaluation, this order permits that a statement
to that effect and the basis for it be included in the preamble if a
full regulatory evaluation of the cost and benefits is not prepared.
Such a determination has been made for this proposed rule. The
reasoning for this determination follows:
Currently, the FAA has no clear standards in part 33 for approval
of a maximum overtorque limit. Engine manufacturers have obtained FAA
approvals based on other certification engine tests and analysis that
did not directly address the considerations for the maximum overtorque
limit. This has allowed for different interpretations of the data by
different FAA offices. Additionally, the Certification Specifications
Engines (CS-E) contain specific standards for the approval of maximum
overtorque limits. These differences result in additional costs and
delays for the U.S. aircraft engine manufacturers when seeking
certification of their engine designs by the EASA for export. The new
proposed rule will harmonize the U.S. and European engine overtorque
requirements, which will eliminate these additional costs and delays.
The FAA estimates there will be no adverse effect as the proposal
would combine existing standards found in part 33 into one single
standard for overtorque, and, as a result, either reduce costs or
impose no net costs on aircraft engine manufacturers. This proposed
rule will reduce regulatory barriers by establishing one standard
consistent with a similar EASA standard. This benefit would justify its
costs and reduce barriers to international trade.
Regulatory Flexibility Determination
The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA)
establishes ``as a principle of regulatory issuance that agencies shall
endeavor, consistent with the objectives of the rule and of applicable
statutes, to fit regulatory and informational requirements to the scale
of the businesses, organizations, and governmental jurisdictions
subject to regulation. To achieve this principle, agencies are required
to solicit and consider flexible regulatory proposals and to explain
the rationale for their actions to assure that such proposals are given
serious consideration.'' The RFA covers a wide-range of small entities,
including small businesses, not-for-profit organizations, and small
governmental jurisdictions.
Agencies must perform a review to determine whether a rule will
have a significant economic impact on a substantial number of small
entities. If the agency determines that it will, the agency must
prepare a regulatory flexibility analysis as described in the RFA.
However, if an agency determines that a rule is not expected to have a
significant economic impact on a substantial number of small entities,
section 605(b) of the RFA provides that the head of the agency may so
certify and a regulatory flexibility analysis is not required. The
certification must include a statement providing the factual basis for
this determination, and the reasoning should be clear.
This proposed rule merely revises and clarifies FAA rulemaking
procedures; the expected outcome is to reduce aircraft engine
certification costs. Therefore, the FAA certifies that this proposed
rule would not have a significant economic impact on a substantial
number of small entities. The FAA solicits comments regarding this
determination.
International Trade Impact Assessment
The Trade Agreements Act of 1979 (Pub. L. 96-39) prohibits Federal
agencies from establishing any standards or engaging in related
activities that create unnecessary obstacles to the foreign commerce of
the United States. Legitimate domestic objectives, such as safety, are
not considered unnecessary obstacles. The statute also requires
consideration of international standards and, where appropriate, that
they be the basis for U.S. standards. The FAA has assessed the
potential effect of this proposed rule and has determined that it
complies with this Act as it would reduce trade barriers by eliminating
the engine-certification-requirement differences related to overtorque
between the United States and European regulations.
Unfunded Mandates Assessment
Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-
4) requires each Federal agency to prepare a written statement
assessing the effects of any Federal mandate in a proposed or
[[Page 15958]]
final agency rule that may result in an expenditure of $100 million or
more (adjusted annually for inflation with the base year 1995) in any
one year by State, local, and tribal governments, in the aggregate, or
by the private sector; such a mandate is deemed to be a ``significant
regulatory action.'' The FAA currently uses an inflation-adjusted value
of $128.1 million in lieu of $100 million. This proposed rule does not
contain such a mandate.
Executive Order 13132, Federalism
The FAA has analyzed this proposed rule under the principles and
criteria of Executive Order 13132, Federalism. We determined that this
action would not have a substantial direct effect on the States, on the
relationship between the national Government and the States, or on the
distribution of power and responsibilities among the various levels of
government, and, therefore, would not have federalism implications.
Environmental Analysis
FAA Order 1050.1E identifies FAA actions that are categorically
excluded from preparation of an environmental assessment or
environmental impact statement under the National Environmental Policy
Act in the absence of extraordinary circumstances. The FAA has
determined this proposed rulemaking action qualifies for the
categorical exclusion identified in Chapter 3, paragraph 312d, and
involves no extraordinary circumstances.
Regulations That Significantly Affect Energy Supply, Distribution, or
Use
The FAA has analyzed this NPRM under Executive Order 13211, Actions
Concerning Regulations that Significantly Affect Energy Supply,
Distribution, or Use (May 18, 2001). We have determined that it is not
a ``significant energy action'' under the executive order because it is
not a ``significant regulatory action'' under Executive Order 12866,
and it is not likely to have a significant adverse effect on the
supply, distribution, or use of energy.
Additional Information
Comments Invited
The FAA invites interested persons to participate in this
rulemaking by submitting written comments, data, or views. We also
invite 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 proposal, explain the reason for any recommended change, and
include supporting data. To ensure the docket does not contain
duplicate comments, please send only one copy of written comments, or
if you are filing comments electronically, please submit your comments
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 proposal, 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 this proposal in light of the comments we receive.
Proprietary or Confidential Business Information
Do not file in the docket information that you consider to be
proprietary or confidential business information. Send or deliver this
information directly to the person identified in the FOR FURTHER
INFORMATION CONTACT section of this document. You must mark the
information that you consider proprietary or confidential. If you send
the information on a disk or CD-ROM, mark the outside of the disk or
CD-ROM and also identify electronically within the disk or CD-ROM the
specific information that is proprietary or confidential.
Under 14 CFR 11.35(b), when we are aware of proprietary information
filed with a comment, we do not place it in the docket. We hold it in a
separate file to which the public does not have access, and we place a
note in the docket that we have received it. If we receive a request to
examine or copy this information, we treat it as any other request
under the Freedom of Information Act (5 U.S.C. 552). We process such a
request under the DOT procedures found in 49 CFR part 7.
Availability of Rulemaking Documents
You can get an electronic copy of rulemaking documents using the
Internet by--
1. Searching the Federal eRulemaking Portal (http://www.regulations.gov);
2. Visiting the FAA's Regulations and Policies Web page at: http://www.faa.gov/regulations_policies/; or Accessing the Government
Printing Office's Web page at: http://www.gpoaccess.gov/fr/index.html.
You can also get a copy by sending a request to the Federal
Aviation Administration, Office of Rulemaking, ARM-1, 800 Independence
Avenue SW., Washington, DC 20591, or by calling (202) 267-9680. Make
sure to identify the docket number, notice number, or amendment number
of this rulemaking.
List of Subjects
14 CFR Part 1
Air transportation, Aircraft, Aviation safety, Safety.
14 CFR Part 33
Air transportation, Aircraft, Aviation Safety, Safety.
The Proposed Amendment
In consideration of the foregoing, the Federal Aviation
Administration proposes to amend parts 1 and 33 of Title 14, Code of
Federal Regulations (14 CFR parts 1 and 33) as follows:
PART 1--DEFINITIONS AND ABBREVIATIONS
1. The authority citation for part 1 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.
2. Amend Sec. 1.1 by adding the definition of ``Maximum engine
overtorque'' in alphabetical order, to read as follows:
Sec. 1.1 General definitions.
* * * * *
Maximum engine overtorque, as it applies to turbopropeller and
turboshaft engines incorporating free power-turbines for all ratings
except one engine inoperative (OEI) ratings of two minutes or less,
means the maximum torque of the free power-turbine rotor assembly, the
inadvertent occurrence of which, for periods of up to 20 seconds, will
not require rejection of the engine from service, or any maintenance
action other than to correct the cause.
* * * * *
PART 33--AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES
3. The authority citation for part 33 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.
4. Amend Sec. 33.7 by adding new paragraph (c)(17) as follows:
Sec. 33.7 Engine ratings and operating limitations.
* * * * *
(c) * * *
(17) Maximum engine overtorque for turbopropeller and turboshaft
engines incorporating free power-turbines.
5. Section 33.84 is added to read as follows:
[[Page 15959]]
Sec. 33.84. Engine Overtorque Test.
(a) If approval of a maximum engine overtorque is sought for an
engine incorporating a free power turbine, compliance with this section
must be demonstrated by testing.
(1) The test may be run as part of the endurance test requirement
of Sec. 33.87. Alternatively, tests may be performed on a complete
engine or equivalent testing on individual groups of components.
(2) Upon conclusion of tests conducted to show compliance with this
section, each engine part or individual groups of components must meet
the requirements of Sec. 33.93(a)(1) and (a)(2).
(b) The test conditions must be as follows:
(1) A total of 15 minutes run at the maximum engine overtorque to
be approved. This may be done in separate runs, each being of at least
2\1/2\ minutes duration.
(2) A power turbine rotational speed equal to the highest speed at
which the maximum overtorque can occur in service. The test speed may
not be more than the limit speed of take-off or OEI ratings longer than
2 minutes.
(3) For engines incorporating a reduction gearbox, a gearbox oil
temperature equal to the maximum temperature when the maximum engine
overtorque could occur in service; and for all other engines, an oil
temperature within the normal operating range.
(4) A turbine entry gas temperature equal to the maximum steady
state temperature approved for use during periods longer than 20
seconds, other than conditions associated with 30-second or 2-minutes
OEI ratings. The requirement to run the test at the maximum approved
steady state temperature may be waived by the FAA if the applicant can
demonstrate that other testing provides substantiation of the
temperature effects when considered in combination with the other
parameters identified in paragraphs (b)(1), (b)(2) and (b)(3) of this
section.
Issued in Washington, DC, on March 20, 2008.
John J. Hickey,
Director, Aircraft Certification Service.
[FR Doc. E8-6148 Filed 3-25-08; 8:45 am]
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