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Airworthiness Standards: Rotorcraft Turbine Engines One-Engine-Inoperative (OEI) Ratings, Type Certification Standards

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Start Preamble

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The Federal Aviation Administration (FAA) is amending the One-Engine-Inoperative (OEI) rating definitions and type certification standards for 30-second OEI, 2-minute OEI, and 30-minute OEI ratings for rotorcraft turbine engines. This action revises the ratings' standards to reflect recent analyses of the ratings' use and lessons learned from completed engine certifications and service experience. This rule harmonizes FAA type certification standards for these ratings with the requirements of the European Aviation Safety Agency in the Certification Specifications for Engines and with proposed requirements for Transport Canada Civil Aviation, thus simplifying airworthiness approvals for import and export.

DATES:

This amendment becomes effective October 17, 2008.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Dorina Mihail, Engine and Propeller Standards Staff, ANE-110, Engine and Propeller Directorate, Aircraft Certification Service, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803-5229; (781) 238-7153; facsimile: (781) 238-7199; e-mail: dorina.mihail@faa.gov.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Authority for This Rulemaking

The FAA's authority to issue rules regarding 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, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce, including minimum safety standards for aircraft engines. This rule is within the scope of that authority because it updates the existing regulations for type certification standards for OEI ratings for rotorcraft turbine engines.

Background

On May 4, 2007, the FAA published a notice of proposed rulemaking (NPRM) titled “Airworthiness Standards: Rotorcraft Turbine Engines One-Engine-Inoperative (OEI) Ratings, Type Certification Standards” (72 FR 25207). The comment period for the NPRM closed on August 2, 2007.

The OEI power ratings provide rotorcraft with higher than takeoff and maximum continuous power ratings needed when one engine of a multi-engine rotorcraft fails or is shut down during flight, such as during takeoff, cruise, or landing. These OEI power rating powers enable the rotorcraft to continue safe flight until it reaches a suitable landing site. Part 33 prescribes airworthiness standards for 30-second OEI, 2-minute OEI, 21/2-minute OEI, 30-minute OEI, and continuous OEI ratings for the issuance of type certificates for rotorcraft turbine engines. All OEI ratings are optional ratings that engine manufacturers may select from those specified in § 33.7.

This final rule harmonizes with the corresponding airworthiness standards for OEI ratings of the European Aviation Safety Agency (EASA) without reducing the existing level of safety.

Summary of Comments

Three commenters, including a turbine engine manufacturer, General Electric (GE); a foreign aviation authority, Transport Canada Civil Aviation (TCCA); and an industry association, Aerospace Industries Association (AIA); responded to the NPRM request for comments. The GE and AIA comments are identical. TCCA had a number of comments. All of the commenters generally supported the proposed changes. All comments included suggested changes, as discussed in the discussion of the final rule below. Start Printed Page 48120

The FAA received comments on the following general areas of the proposal:

  • Instrument connection.
  • Fuel system.
  • Endurance test.
  • Engine overtemperature test.
  • Airworthiness Limitations Section.

Discussion of the Final Rule

Below is a more detailed discussion of the rule as it relates to the comments on the proposal.

Instrument Connection

We revised § 33.29(c) to specify that the applicant must provide a means or a provision for a means to satisfy the requirements for the use of the defined 30-second OEI and 2-minute OEI ratings. The applicant, for example an engine manufacturer, may satisfy “a means” by providing a recorder to record entry into the OEI power bands. Alternatively, the applicant may fulfill “a provision for a means” by specifying that the installer provide a recorder to record entry into the OEI power bands. We also added a new § 33.29(c)(4) to specify the requirements for verification of the proper operation of indicating, recording, and retrieval systems.

The TCCA commented that existing § 33.29(c) should not be changed because full compliance to crew interface would be difficult to achieve at engine certification. The TCCA claimed the proposed changes to § 33.29(c) are redundant to the requirements of §§ 27.1305 and 29.1305.

We believe the requirement for the engine to have either a means or a provision for a means is engine specific and can be met at engine certification. Advisory circulars will provide further guidance. The FAA harmonized this change with EASA's rule. Section 33.29(c) is adopted without change.

We also proposed to add § 33.29(d) which limits resetting the recordings required by paragraph (c) to only while on the ground.

The TCCA believes that compliance to proposed § 33.29(d) can only be found at rotorcraft, not engine, certification and this section, therefore, should not be part of engine requirements.

The FAA partially agrees with this comment. We determined that § 33.29(d) should apply to § 33.29(c)(2) and (c)(3) but not to § 33.29(c)(1) and (c)(4). Specifically, we found that in-flight resetting of the pilot alert required under (c)(1) and the routine verification required under (c)(4) should not be addressed by engine regulations. We retained the § 33.29(d) requirement that recordings under (c)(2) and (c)(3) should not be reset in-flight because we find these requirements should be met at engine certification. We, therefore, modified § 33.29(d) in the final rule to refer only to § 33.29(c)(2) and (c)(3).

Fuel System

We proposed a revision to § 33.67(d) to clarify the intent of “automatic control” of the 30-second OEI power is to control the engine operating conditions, which should not exceed the engine's operating limits. We clarified in the preamble of the NPRM that the applicant's design, however, should not limit the time interval at which OEI power is used. This design feature enables the pilot to exceed OEI time limits to safely land the rotorcraft in an in-flight emergency as permitted by § 91.3(b).

GE requested clarification that the OEI power limit can be exceeded in the event of an emergency under the requirements of § 33.67(d).

The intent of § 33.67(d) is that use of 30-second OEI power should be subject to automatic control and should not be exceeded. This automatic control requirement is intended to avoid the need for the pilot to monitor engine parameters, such as output shaft torque or power, output shaft speed, gas producer speed, and gas path temperature during OEI operation. Once the automatic control system is activated, it automatically controls the 30-second OEI power and prevents the engine from exceeding its specified operating limits. Section 33.67(d) is adopted as proposed.

Endurance Test

The amended § 33.87 reduces test complexity and adds test flexibility under the revisions to § 33.87(a); harmonizes the test schedule under § 33.87(c) with that of the Certification Specifications for Engines (CS-E); and clarifies the test schedule and test sequence under § 33.87(f).

We proposed to revise § 33.87(a)(5) so the maximum air bleed for engine and aircraft services under § 33.87(a)(5) need not be used for the final 120-minute test required under § 33.87(f)(1) through (f)(8) if the applicant can show by testing, or analysis based on testing, that the validity of the endurance test is preserved. This proposed revision was intended to reduce test complexity and improve the flexibility needed to attain the key parameters (speed, temperature and torque) during the tests.

We also proposed to revise § 33.87(a)(6) to allow the applicant to run the final 120-minute test under §§ 33.87(f)(1) through (f)(8) without loading the accessory drives and mounting attachments if the applicant can substantiate that the durability of any accessory drive or engine component is not significantly affected.

The TCCA commented that § 33.87(a)(5) should not require the maximum air bleed and § 33.87(a)(6) should not require loading of accessory drive and mounting attachments to be part of the test configuration for § 33.87(f) test sequences. The TCCA recommended changes to § 33.87(a)(5) and (a)(6) that do not mention “120-minute,” which is the minimum time duration of the test required under paragraph (f).

We have revised § 33.87(a)(5) and (a)(6) in the final rule by removing references to “120-minute.” These changes clarify the exceptions specified in § 33.87(a)(5) and (a)(6) are for the entire test duration performed under § 33.87(f).

GE recommended changes to § 33.87 it believes would ensure FAA requirements are not more severe than EASA's for the endurance test requirements under § 33.87(a)(3) and (a)(7).

We find that GE's recommendation would substantially affect § 33.87 requirements for all non-OEI engine ratings. Such a change is beyond the scope of this rule.

Engine Overtemperature Test

We proposed to revise § 33.88(a) to clarify that these requirements apply to all engine ratings, including all OEI ratings other than the 30-second and 2-minute OEI ratings, regardless of whether the engine is equipped with an automatic temperature control.

The TCCA disagreed with our proposed change to § 33.88(a) because it claimed the proposed new language could result in more tests being performed than is intended by the proposal.

We agree that the proposed language in § 33.88(a) could be interpreted to also apply to 30-second and 2-minute OEI ratings and result in unintended testing. We are, therefore, withdrawing the proposed change to § 33.88(a). We have, however, revised § 33.88(b) in the final rule to clarify that testing under § 33.88(a) applies to all engine ratings, except for 30-second OEI and 2-minute OEI ratings.

The TCCA commented that §§ 33.88(b) and 33.93(b)(2) should refer to “mandatory inspections and maintenance actions.”

We find that § 33.4 and Appendix A to Part 33 adequately reference mandatory inspections and maintenance actions. Start Printed Page 48121

Airworthiness Limitations Section, Appendix A

We are revising Appendix A, Section A33.4, Airworthiness Limitations Section (ALS), by adding a new paragraph for rotorcraft engines having 30-second OEI and 2-minute OEI ratings. For these engines, we require the applicant to prescribe mandatory post-flight inspection and maintenance actions in the ALS of the Instructions for Continued Airworthiness following the use of these ratings. In order to harmonize with CS-E 25, we are requiring the applicant to create a mandatory in-service engine evaluation program to ensure continued adequacy of the airworthiness instructions for the engines.

The 30-second OEI and 2-minute OEI ratings allow for limited use in service followed by mandatory inspection and maintenance. These ratings assume some engine parts or components may not be suitable for further use and will need to be replaced after the application of these ratings. The mandatory inspections and maintenance actions following the use of 30-second OEI or 2-minute OEI ratings must (1) identify and correct any component distress that could significantly reduce subsequent engine reliability or prevent the engine from achieving 30-second OEI and 2-minute OEI power ratings; and (2) maintain the engine in condition for safe OEI flight. The applicant must validate the adequacy of the required inspections and maintenance actions.

The TCCA commented that the requirements for validation of inspection and maintenance actions should not be included in paragraph (b)(1) of A33.4 but under § 33.90.

The FAA partially agrees. We find the requirement for validation of inspection and maintenance actions is more appropriate in the ALS. Section 33.90 establishes when the initial maintenance inspection is required. We revised proposed paragraphs in A33.4(b) to separate the ALS content requirements from the validation requirements. We revised A33.4(b) into these separate requirements: Paragraph (b)(1) specifies the content of the ALS and paragraph (b)(2) specifies the validation requirements. We redesignated proposed (b)(2) as (b)(3) and revised (b)(3) to reference (b)(1) for the requirements related to the instructions for mandatory post-flight inspection and maintenance actions.

The TCCA also commented that it is inappropriate to place an in-service engine evaluation program in the airworthiness requirements of A33.4 as this would become an “open issue” at engine type certification. The TCCA recommends instead that this program be described in an advisory circular as an acceptable means of compliance.

We intend that the applicant should submit an in-service engine evaluation program at engine certification, and that this program should have provisions for the applicant to continue its evaluation throughout the service life of the engine. We note that this requirement harmonizes with CS-E 25 and is unlikely to become a certification issue.

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 there is no current or new requirement for information collection associated with this amendment.

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 reviewed the corresponding ICAO Standards and Recommended Practices and has identified no differences with these regulations.

Economic Assessment, Regulatory Flexibility Determination, 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 final 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 final rule. The reasoning for this determination follows:

This final rule codifies existing certification practices while maintaining the existing level of safety. The existing certification practices reflect the ratings' use and lessons learned from completed engine certifications and service experience.

The final rule also harmonizes the FAA standards with those of EASA. Presently, engine manufacturers must satisfy both United States and European requirements to certify and market part 33 engines in both the United States and in Europe. Meeting two sets of certification requirements raises the cost of development often with no increase in safety. In the interest of fostering international trade, lowering the cost of development, and making the certification process more efficient, the FAA, EASA, and manufacturers have worked to create to the maximum possible extent a single set of certification requirements accepted in both the United States and Europe.

This final rule harmonizes FAA type certification standards for OEI ratings with the requirements already in existence in Europe, thus simplifying airworthiness approvals for import and export. The FAA has not attempted to quantify the cost savings that may accrue due to harmonization of this rule, beyond noting that they will contribute to certification and validation savings. There is also potential for increased safety by having clearer and more explicit regulations. In addition, safety after an engine failure or shutdown under the requirements contained in this final rule will be at least equivalent to safety under the previous requirements and certification practices. We received no comments regarding our initial minimal cost determination in the NPRM, and arrive at the same minimal cost determination for this final rule. Start Printed Page 48122

Currently, manufacturers that hold OEI ratings are: General Electric Aircraft Engines, Rolls-Royce Corporation (Indiana), Light Helicopter Turbine Engine Company (LHTEC), and Honeywell International, Inc. These manufacturers also seek validation in Europe. For example, the General Electric CT7-8 series turbine engine was validated in Europe in November 2004. Because all existing manufacturers with OEI ratings also seek validation in Europe, where the requirements of this final rule are already in place, it codifies common industry business practice.

Because this final rule codifies existing certification practices while maintaining the existing level of safety, we have determined that this final rule is not a “significant regulatory action” as defined in section 3(f) of Executive Order 12866, and is not “significant” as defined in DOT's Regulatory Policies and Procedures. The benefits of this final rule justify the costs and the existing level of safety will be preserved.

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.

In the Initial Regulatory Flexibility Determination, we found that there would not be a significant economic impact on a substantial number of small entities. There were no comments on our initial regulatory flexibility determination.

Using the Small Business Administration Size Standards, we find that there are no small business manufacturers who hold OEI ratings. In addition, this rule reduces certification costs. Because this rule reduces costs and no small businesses are affected, our final regulatory flexibility determination is that this rule will not have a significant economic impact on a substantial number of small entities.

Therefore, as the Acting FAA Administrator, I certify that this final rule will not have a significant economic impact on a substantial number of small entities.

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.

This final rule considers and incorporates an international standard as the basis of an FAA regulation. Thus this final rule complies with the Trade Agreements Act of 1979 and does not create unnecessary obstacles to international trade.

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 final agency rule that may result in an expenditure of $100 million or more (in 1995 dollars) 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 $136.1 million in lieu of $100 million.

The FAA has assessed the potential effect of this final rule and determined that it does not contain such a mandate. Therefore, the requirements of Title II of the Unfunded Mandates Reform Act of 1995 do not apply.

Executive Order 13132, Federalism

The FAA has analyzed this final rule under the principles and criteria of Executive Order 13132, Federalism. We determined that this action will not have a substantial direct effect on the States, or 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, does 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 rulemaking action qualifies for the categorical exclusion identified in paragraph 312f and involves no extraordinary circumstances.

Regulations That Significantly Affect Energy Supply, Distribution, or Use

The FAA has analyzed this final rule 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.

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

3. 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 amendment number or docket number of this rulemaking.

Anyone is able to search the electronic form of all comments received into any of our dockets by the name of the individual submitting the comment (or signing the comment, if submitted on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act statement in the Federal Register Start Printed Page 48123published on April 11, 2000 (Volume 65, Number 70; Pages 19477-78) or you may visit http://DocketsInfo.dot.gov.

Small Business Regulatory Enforcement Fairness Act

The Small Business Regulatory Enforcement Fairness Act (SBREFA) of 1996 requires the FAA to comply with small entity requests for information or advice about compliance with statutes and regulations within its jurisdiction. If you are a small entity and you have a question regarding this document, you may contact your local FAA official, or the person listed under the FOR FURTHER INFORMATION CONTACT heading at the beginning of the preamble. You can find out more about SBREFA on the Internet at http://www.faa.gov/​regulations_​policies/​rulemaking/​sbre_​act/​.

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List of Subjects

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The Amendment

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In consideration of the foregoing, the Federal Aviation Administration amends parts 1 and 33 of Title 14, Code of Federal Regulations as follows:

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PART 1—DEFINITIONS AND ABBREVIATIONS

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1. The authority citation for part 1 continues to read as follows:

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

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2. Amend § 1.1 by revising the definitions for “Rated 30-second OEI power,” “Rated 2-minute OEI power,” “Rated continuous OEI power,” “Rated 30-minute OEI power,” and “Rated 2

End Amendment Part
General definitions.
* * * * *

Rated 30-second OEI Power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, for continuation of one flight operation after the failure or shutdown of one engine in multiengine rotorcraft, for up to three periods of use no longer than 30 seconds each in any one flight, and followed by mandatory inspection and prescribed maintenance action.

Rated 2-minute OEI Power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, for continuation of one flight operation after the failure or shutdown of one engine in multiengine rotorcraft, for up to three periods of use no longer than 2 minutes each in any one flight, and followed by mandatory inspection and prescribed maintenance action.

Rated continuous OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, and limited in use to the time required to complete the flight after the failure or shutdown of one engine of a multiengine rotorcraft.

* * * * *

Rated 30-minute OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter, and limited in use to one period of use no longer than 30 minutes after the failure or shutdown of one engine of a multiengine rotorcraft.

Rated 21/2-minute OEI power, with respect to rotorcraft turbine engines, means the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established for the engine under part 33 of this chapter for periods of use no longer than 21/2 minutes each after the failure or shutdown of one engine of a multiengine rotorcraft.

* * * * *
Start Part

PART 33—AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES

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3. The authority citation for part 33 continues to read as follows:

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

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4. Amend § 33.5 to add a new paragraph (b)(4) to read as follows:

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Instruction manual for installing and operating the engine.
* * * * *

(b) * * *

(4) For rotorcraft engines having one or more OEI ratings, applicants must provide data on engine performance characteristics and variability to enable the aircraft manufacturer to establish aircraft power assurance procedures.

* * * * *
Start Amendment Part

5. Amend § 33.29 by revising paragraph (c) and adding paragraph (d) to read as follows:

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Instrument connection.
* * * * *

(c) Each rotorcraft turbine engine having a 30-second OEI rating and a 2-minute OEI rating must have a means or a provision for a means to:

(1) Alert the pilot when the engine is at the 30-second OEI and the 2-minute OEI power levels, when the event begins, and when the time interval expires;

(2) Automatically record each usage and duration of power at the 30-second OEI and 2-minute OEI levels;

(3) Alert maintenance personnel in a positive manner that the engine has been operated at either or both of the 30-second and 2-minute OEI power levels, and permit retrieval of the recorded data; and

(4) Enable routine verification of the proper operation of the above means.

(d) The means, or the provision for a means, of paragraphs (c)(2) and (c)(3) of this section must not be capable of being reset in flight.

Start Amendment Part

6. Revise § 33.67(d) to read as follows:

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Fuel system.
* * * * *

(d) Rotorcraft engines having a 30-second OEI rating must incorporate a means, or a provision for a means, for automatic availability and automatic control of the 30-second OEI power within its operating limitations.

Start Amendment Part

7. Amend § 33.87 by:

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A. Redesignating paragraphs (c)(2) and paragraphs (c)(4) through (c)(6) as paragraphs (c)(4) through (c)(7);

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B. By adding new paragraph (c)(2); and

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C. By revising paragraphs (a)(5), (a)(6), (c)(3), newly redesignated paragraphs (c)(4) through (c)(7), (f) introductory text, (f)(4) and (f)(8) to read as follows:

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Endurance test.

(a) * * *

(5) Maximum air bleed for engine and aircraft services must be used during at least one-fifth of the runs, except for the test required under paragraph (f) of this section, provided the validity of the test is not compromised. However, for these runs, the power or 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. Start Printed Page 48124

(6) Each accessory drive and mounting attachment must be loaded in accordance with paragraphs (a)(6)(i) and (ii) of this section, except as permitted by paragraph (a)(6)(iii) of this section for the test required under paragraph (f) of this section.

(i) The load imposed by each accessory used only for aircraft service must be the limit load specified by the applicant for the engine drive and attachment point during rated maximum continuous power or thrust and higher output.

(ii) The endurance test of any accessory drive and mounting attachment under load may be accomplished on a separate rig if the validity of the test is confirmed by an approved analysis.

(iii) The applicant is not required to load the accessory drives and mounting attachments when running the tests under paragraphs (f)(1) through (f)(8) of this section if the applicant can substantiate that there is no significant effect on the durability of any accessory drive or engine component. However, the applicant must add the equivalent engine output power extraction from the power turbine rotor assembly to the engine shaft output.

* * * * *

(c) * * *

(2) Rated maximum continuous and takeoff power. Thirty minutes at—

(i) Rated maximum continuous power during fifteen of the twenty-five 6-hour endurance test cycles; and

(ii) Rated takeoff power during ten of the twenty-five 6-hour endurance test cycles.

(3) Rated maximum continuous power. One hour at rated maximum continuous power.

(4) Rated 30-minute OEI power. Thirty minutes at rated 30-minute OEI power.

(5) Incremental cruise power. Two hours and 30 minutes at the successive power lever positions corresponding with not less than 15 approximately equal speed and time increments between maximum continuous engine rotational speed and ground or minimum idle rotational speed. For engines operating at constant speed, power may be varied in place of speed. If there are significant peak vibrations anywhere between ground idle and maximum continuous conditions, the number of increments chosen must be changed to increase the amount of running conducted while subject to peak vibrations up to not more than 50 percent of the total time spent in incremental running.

(6) Acceleration and deceleration runs. Thirty minutes of accelerations and decelerations, consisting of six cycles from idling power to rated takeoff power and maintained at the takeoff power lever position for 30 seconds and at the idling power lever position for approximately 41/2 minutes. In complying with this paragraph, the power control lever must be moved from one extreme position to the other in not more than one second. If, however, different regimes of control operations are incorporated that necessitate scheduling of the power control lever motion from one extreme position to the other, then a longer period of time is acceptable, but not more than two seconds.

(7) Starts. One hundred starts, of which 25 starts must be preceded by at least a two-hour engine shutdown. There must be at least 10 false engine starts, pausing for the applicant's specified minimum fuel drainage time, before attempting a normal start. There must be at least 10 normal restarts not more than 15 minutes after engine shutdown. The remaining starts may be made after completing the 150 hours of endurance testing.

* * * * *

(f) Rotorcraft Engines for which 30-second OEI and 2-minute OEI ratings are desired. For each rotorcraft engine for which 30-second OEI and 2-minute OEI power ratings are desired, and following completion of the tests under paragraphs (b), (c), (d), or (e) of this section, the applicant may disassemble the tested engine to the extent necessary to show compliance with the requirements of § 33.93(a). The tested engine must then be reassembled using the same parts used during the test runs of paragraphs (b), (c), (d), or (e) of this section, except those parts described as consumables in the Instructions for Continued Airworthiness. Additionally, the tests required in paragraphs (f)(1) through (f)(8) of this section 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 it were continued. The applicant must conduct the following test sequence four times, for a total time of not less than 120 minutes:

* * * * *

(4) 30-minute OEI power, continuous OEI power, or maximum continuous power. Five minutes at whichever is the greatest of rated 30-minute OEI power, rated continuous OEI power, or rated maximum continuous power, except that, during the first test sequence, this period shall be 65 minutes. However, where the greatest rated power is 30-minute OEI power, that sixty-five minute period shall consist of 30 minutes at 30-minute OEI power followed by 35 minutes at whichever is the greater of continuous OEI power or maximum continuous power.

* * * * *

(8) Idle. One minute at flight idle.

* * * * *
Start Amendment Part

8. Amend § 33.88 by removing paragraph (b), redesignating (c) and (d) as paragraphs (b) and (c), respectively; and revising the text of the newly designated paragraph (b) to read as follows:

End Amendment Part
Engine overtemperature test.
* * * * *

(b) In addition to the test requirements in paragraph (a) of this section, each engine for which 30-second OEI and 2-minute OEI ratings are desired, that incorporates a means for automatic temperature control within its operating limitations in accordance with § 33.67(d), must run for a period of 4 minutes at the maximum power-on rpm with the gas temperature at least 35 °F (19 °C) higher than the maximum operating limit at 30-second OEI rating. Following this run, the turbine assembly may exhibit distress beyond the limits for an overtemperature condition provided the engine is shown by analysis or test, as found necessary by the FAA, to maintain the integrity of the turbine assembly.

* * * * *
Start Amendment Part

9. Revise § 33.93(b)(2) to read as follows:

End Amendment Part
Teardown inspection.
* * * * *

(b) * * *

(2) Each engine may exhibit deterioration in excess of that permitted in paragraph (a)(2) of this section, including some engine parts or components that may be unsuitable for further use. The applicant must show by inspection, analysis, test, or by any combination thereof as found necessary by the FAA, that structural integrity of the engine is maintained; or

* * * * *
Start Amendment Part

10. Amend Appendix A to part 33 by revising section A33.4 to read as follows:

End Amendment Part Start Appendix

Appendix A to Part 33—Instructions for Continued Airworthiness

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A33.4 AIRWORTHINESS LIMITATIONS SECTION

The Instructions for Continued Airworthiness must contain a section titled Airworthiness Limitations that is segregated and clearly distinguishable from the rest of the manual. Start Printed Page 48125

(a) For all engines:

(1) The Airworthiness Limitations section must set forth each mandatory replacement time, inspection interval, and related procedure required for type certification. If the Instructions for Continued Airworthiness consist of multiple documents, the section required under this paragraph must be included in the principal manual.

(2) This section must contain a legible statement in a prominent location that reads: “The Airworthiness Limitations section is FAA approved and specifies maintenance required under §§ 43.16 and 91.403 of Title 14 of the Code of Federal Regulations unless an alternative program has been FAA approved.”

(b) For rotorcraft engines having 30-second OEI and 2-minute OEI ratings:

(1) The Airworthiness Limitations section must also prescribe the mandatory post-flight inspections and maintenance actions associated with any use of either 30-second OEI or 2-minute OEI ratings.

(2) The applicant must validate the adequacy of the inspections and maintenance actions required under paragraph (b)(1) of this section A33.4.

(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 (b)(1) of this section A33.4 and of the data for § 33.5(b)(4) pertaining to power availability. 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 30-second OEI or 2-minute OEI ratings.

End Appendix Start Signature

Issued in Washington, DC, on July 10, 2008.

Robert A. Sturgell,

Acting Administrator.

End Signature End Supplemental Information

[FR Doc. E8-18936 Filed 8-15-08; 8:45 am]

BILLING CODE 4910-13-P