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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Parts 1 and 33 
          - [Docket No. FAA-2007-27899; Notice No. 07-05] 
          - RIN 2120-AI96 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM). 

# SUMMARY:

                        The Federal Aviation Administration (FAA) is proposing to amend OEI rating definitions and type certification standards for 30-second OEI, 2-minute OEI, and 30-minute OEI ratings for rotorcraft turbine engines. This proposed rule, if adopted, would revise the ratings' standards to reflect recent analyses of the ratings' usage and lessons learned from completed engine                               ( print page 25208)                            certifications and service experience. This proposal harmonizes FAA type certification standards for these ratings with the requirements of the European Aviation Safety Agency in the Certification Specifications for Engines (CS-E) and with proposed requirements for Transport Canada Civil Aviation. If adopted, the proposed changes would establish nearly uniform certification standards for ratings for rotorcraft turbine engines certificated in the United States under part 33 and in European countries under CS-E, thus simplifying airworthiness approvals for import and export.                     

# DATES:

Send your comments on or before August 2, 2007. 

# ADDRESSES:

You may send comments, identified by Docket No. FAA-2007-27899, using any of the following methods: 
      -  DOT Docket Web site:                          Go to                          http://dms.dot.gov                          and follow the instructions for sending your comments electronically.                     
      -  Government-wide rulemaking Web site:                          Go to                          http://www.regulations.gov                          and follow the instructions for sending your comments electronically.                     
      -  Mail:                          Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001.                     
      -  Fax:                          1-202-493-2251.                     
      -  Hand Delivery:                          Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.                     

                        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://dms.dot.gov,*                         including any personal information that you provide. For more information, see the Privacy Act discussion in the                         **SUPPLEMENTARY INFORMATION**                         section of this document.                     

*Docket:*                         To read background documents or comments received, go to                         *http://dms.dot.gov*                         at any time or to Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.                     

# 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.*

# SUPPLEMENTARY 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. We ask that you send us two copies of written comments. 

                    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. The docket is available for public inspection before and after the comment closing date. If you wish to review the docket in person, go to the address in the                     **ADDRESSES**                     section of this preamble between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. You may also review the docket using the Internet at the Web address in the                     **ADDRESSES**                     section.                 

*Privacy Act:*                     Using the search function of our docket Web site, anyone can find and read the comments received into any of our dockets, including the name of the individual sending the comment (or signing the comment on behalf of 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://dms.dot.gov.*

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 late if it is possible to do so without incurring expense or delay. We may change this proposal in light of the comments we receive. 

If you want the FAA to acknowledge receipt of your comments on this proposal, include with your comments a pre-addressed, stamped postcard on which the docket number appears. We will stamp the date on the postcard and mail it to you. 

## Availability of Rulemaking Documents 

You can get an electronic copy using the Internet by: 

                    1. Searching the Department of Transportation's electronic Docket Management System (DMS) Web page (                    *http://dms.dot.gov/​search*):                 

                    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.access.gpo.gov/​su_​docs/​aces/​aces140.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. 

## Background 

                    The One-Engine-Inoperative (OEI) rating powers provide rotorcraft with higher than takeoff and maximum continuous rating powers during takeoff, cruise, and landing when one or more engines of a multi-engine rotorcraft fails or is shutdown. These OEI 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, 2                    1/2                    -minute OEI, 30-minute OEI, and other 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.                 

The Certifications Specifications—Engines prescribe corresponding airworthiness standards of the European Aviation Safety Agency for these ratings. While these standards are similar, they differ in certain regulations. Non-uniform standards impose a regulatory hardship on applicants seeking certification under both sets of standards in the form of additional costs and delays in the time required for certification. 

                    The FAA is committed to promoting harmonization. As part of this commitment, the FAA, with the European Joint Aviation Authorities (JAA) and Transport Canada Civil Aviation, developed a harmonized Terms of Reference for “2-Minute and 30-Second One-Engine-Out Ratings” in April 1992. The Terms of Reference established a joint effort to review and harmonize the requirements and interpretations for OEI ratings under part 33 and the corresponding Joint Aviation Requirements—Engines (JAR-E). The Aviation Rulemaking Advisory Committee (ARAC) assigned the task of harmonizing the differing OEI ratings to its Engine Harmonization Working Group, which consisted of representatives from the FAA, JAA, TC,                           ( print page 25209)                        as well as from U.S., Canadian, and European industries.                 

On February 29, 2000, the Engine Harmonization Working Group reported its recommendations to the ARAC, which recommended that the FAA proceed with rulemaking. This NPRM reflects the ARAC recommendations. 

## Section-by-Section Discussion of the Proposals 

The working group developed and agreed to the following proposals. The proposed changes to parts 1 and 33 contain language similar to that proposed for JAR-E, and subsequently adopted in the CS-E, thereby establishing equivalency and creating consistency between the regulations. 

### Section 1.1 Definitions 

                    The current definitions of rated OEI powers refer to engine failure but not to engine shutdown. We are proposing, therefore, to revise the definition of rated 30-second OEI, rated 2-minute OEI, rated 2                    1/2                    -minute OEI, rated 30-minute OEI, and rated continuous OEI powers to include engine shutdown. In addition, to be consistent with the usage definitions of 30-second OEI and 2-minute OEI ratings, we are proposing to revise the “period of use” for the 2                    1/2                    -minute OEI rating from “a period of use” to “periods of use.”                 

### Section 33.5  Instruction Manual for Installing and Operating the Engine 

We are proposing to add a new § 33.5(b)(4), applicable to rotorcraft engines having one or more OEI ratings, which would require applicants to provide engine data to aircraft manufacturers in support of aircraft power availability requirements, such as those specified in §§ 27.45(f) and 29.45(f). Since the power assurance data will not include a check of the highest OEI rating power level due to potential rapid engine hardware deterioration, the applicant must provide the necessary engine performance characteristics and variability to the engine installer. This data will enable the installer to establish power assurance procedures that enable the extrapolation of data to the highest OEI rating power. The engine database should include: a thermodynamic model; data gained from experience during development and certification testing; and data derived from service experience from engines of similar design, whenever applicable. 

### Section 33.29 Instrument Connection 

We are proposing to revise § 33.29(c) to specify that the applicant must provide a means or a provision for a means to record the entry into the defined 30-second OEI and 2-minute OEI rating power bands. 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. 

The revised proposal would also require a means to indicate to the pilot the entry into the power bands, the corresponding impending time expiration, and the time expiration point. The automatic recording system must record the number of usages of 30-second OEI and/or 2-minute OEI rating powers and the time of each usage, or accumulated time, including any exceedance of 30-second OEI and 2-minute OEI operating limitations or relevant time limitations. 

The automatic recording system should also provide a means to alert the maintenance personnel that the usage and/or exceedance of the 30-second and 2-minute OEI ratings has taken place. The required means for alerting the pilot, maintenance personnel, and the automatic recording system must not be capable of being reset in flight and must only be reset by maintenance personnel after retrieval of recorded data. 

The proposal would delete the redundant design requirements of § 33.29(c)(2). The automatic data recording requirements of the existing § 33.29(c)(3), with a minor wording change for clarification, will become the new § 33.29(c)(2). 

This proposal would add a new requirement designated as new § 33.29(c)(3) to alert maintenance personnel when the engines have been operated at the rating powers and of the need to retrieve the recorded engine data. A new § 33.29(c)(4) would specify the requirements for verification of the proper operation of indicating, recording, and retrieval systems. In addition, a new § 33.29(d) would specify resetting the recording on the ground only. 

### Section 33.67 Fuel System 

The operating conditions requiring the use of 30-second OEI ratings may require the pilot to perform simultaneous actions to maintain safe flight. Therefore, an automatic means that does not require pilot input or control, other than a termination command, must apply and control the rating power. 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 the OEI operation. Once the system is activated, it automatically controls the 30-second OEI power and prevents the engine from exceeding its specified operating limits. 

We are proposing to revise § 33.67(d) to clarify that the intent of the proposed “automatic control” is to control the engine operating conditions, which should not exceed the engine's operating limits. The applicant's design, however, should not limit the time at which OEI power is used. This will enable the pilot to exceed OEI time limitations to safely land the rotorcraft in an in-flight emergency as permitted by § 91.3(b). 

### Section 33.87  Endurance Test 

                    For rotorcraft engines having 30-second and 2-minute OEI ratings, the applicant must consider all applicable paragraphs of § 33.87(a) in running the tests under § 33.87(f). However, to reduce test complexity, and to improve the flexibility needed to attain the key parameters (speed, temperature and torque) during the tests, we are proposing to allow that the maximum air bleed for engine and aircraft services under § 33.87(a)(5) need not be used for the tests 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. The analysis should include, but is not limited to (1) The effect of the bleed air extraction on the engine secondary air system that provides cooling air to various engine components, and (2) the thermodynamic cycle effects of bleed (                    *e.g.*, core speed to output shaft speed changes) which may enhance the engine's ability to meet the teardown inspection requirements of § 33.93(b)(2).                 

This proposal would allow the applicant to run the tests 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. However, to meet the requirements of § 33.87(a)(6) without the power turbine accessory drives loaded during the test, the applicant must add equivalent power required for loading these accessory drives. This power must be added to the output drive shaft so that the power turbine rotor assembly is operated at or above the levels as when the power turbine accessory drives are loaded. 

                    This proposal would clarify the intent of the test schedule for the first test sequence of the existing § 33.87(f)(4) test                           ( print page 25210)                        by adding a new sentence, “However, where the greatest is the 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.” The proposal would also clarify the idle condition of § 33.87(f)(8) as flight idle.                 

This proposal would specify that the four test sequences of the 2-hour test under § 33.87(f) are to be run continuously without stoppage. If a stop occurs, the applicant typically would need to repeat the interrupted sequence in full. However, the sequence may be re-started from the interrupt point if there are technical justifications acceptable to the FAA. If the FAA determines that the sequence need not be repeated in its entirety, then the test should be re-started from a point where the engine thermal condition would be the same as at the time of interruption. If an excessive number of interruptions occur, the applicant would be required to repeat the entire § 33.87(f) test. 

Additionally, we are proposing to revise the test schedule under § 33.87(c) for the 30-minute OEI rating to agree with the schedule in CS-E. The result would be the harmonization of the endurance test schedule for engines having a 30-minute OEI rating. The proposal would replace the existing § 33.87(c)(2) with a thirty-minute test at (a) Rated maximum continuous power during fifteen of the twenty-five 6-hour endurance test cycles; and (b) rated takeoff power during ten of the twenty-five 6-hour endurance test cycles. The existing § 33.87(c)(2) would be redesignated § 33.87(c)(4). The duration of the test in the existing § 33.87(c)(3) would be reduced from 2 hours to 1 hour. The existing § 33.87(c)(4) would be redesignated as § 33.87(c)(5) with the number of time and speed increments increased from 12 to 15, and with total running time increased from 2 hours to 2 hours and 30 minutes. The existing § 33.87(c)(5) and (c)(6) would be redesignated as § 33.87(c)(6) and (c)(7), respectively. 

### Section 33.88 Engine Overtemperature Test

We are proposing to delete the existing § 33.88(b), which refers to obtaining OEI ratings when the engine does not incorporate a means to limit gas temperature. This paragraph is not needed because the new § 33.67(d) requires automatic control of the 30-second OEI power within its gas temperature limit. The proposal would incorporate the existing test requirements in § 33.88(c) into the new § 33.88(b), which applies only to engines having the combined 30-second OEI and 2-minute OEI ratings. We are proposing to revise § 33.88(a) to apply to all other ratings, including all OEI ratings other than the combination specified above, regardless of whether the engine is equipped with an automatic temperature control. 

### Section 33.93 Teardown Inspection 

In meeting the teardown inspection requirements after the 2-hour endurance tests of § 33.87(f), the applicant would be required to show that no failure of any significant engine component becomes evident during the test, shutdown, or the subsequent teardown inspection. For components that are distressed beyond serviceable limits by this test, the applicant must show that the inspections and mandatory maintenance actions for these components, specified in the Instructions for Continued Airworthiness (ICA), are adequate for maintaining their continued airworthiness. 

Additionally, the applicant would need to evaluate component condition against a minimum hardware condition that can be expected for in-service engines. For the purpose of § 33.93(b)(2), engine parts that can affect structural integrity include, but are not limited to, mounts, cases, bearing supports, shafts, and rotors. We are proposing to remove the reference in § 33.93(b)(2) to the above mentioned components to emphasize that after the test the applicant needs to consider deterioration of any engine component that could affect the structural integrity of the engine, not just those listed above. 

### Appendix A33.4 Airworthiness Limitation Section 

We are proposing to revise 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 will require the applicant to prescribe mandatory post-flight inspection and maintenance actions in the ALS of the ICA following the use of these ratings. We will also require the applicant to create a mandatory in-service engine evaluation program to ensure the continued adequacy of the airworthiness instructions for the engines. 

The concept of the 30-second OEI and 2-minute OEI ratings is that of limited use in service followed by mandatory inspection and maintenance. This concept assumes that 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 be capable of (1) Identifying and correcting any component distress that could significantly reduce subsequent engine reliability or prevent the engine from achieving 30-second OEI and 2-minute OEI rating powers; and (2) maintaining the engine in condition for safe OEI flight. This proposal requires the applicant to prescribe the mandatory post-flight inspection and maintenance actions in the ALS of the ICA following the use of either of these two ratings, prior to next flight, regardless of the frequency of usage and the condition of the engine. The applicant must validate the adequacy of the required inspections and maintenance actions. 

The required inspections and maintenance actions are normally determined through certification testing supplemented by development testing and service experience of engines of the same type with similar design at the time of certification. Differences, however, may exist in hardware conditions and power availability characteristics between in-service engines and the conditions and characteristics of the engine prior to the § 33.87(f) tests. Similarly, differences may exist in power assurance characteristics for in-service engines after usage of 30-second or 2-minute OEI ratings and the characteristics observed following the § 33.87(f) tests. 

Therefore, we are proposing an in-service evaluation program in the ALS to obtain relevant data concerning the condition of hardware and power availability at various stages in the life of the engine. The data should be compared with corresponding data observed during certification that defined the post-flight inspection and maintenance actions. If the data obtained from the in-service program indicates that the in-service differences are not properly accounted for, then this data should be used to modify the instructions as appropriate. To achieve the objectives of the program, the engine manufacturer must ensure that operators understand and are aware of the need for the procedures to properly collect and return information needed by the manufacturer. 

## Rulemaking Analyses and Notices 

### 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                           ( print page 25211)                        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 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 rotorcraft engine OEI ratings. 

### 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 are 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 determined there are no ICAO Standards and Recommended Practices that correspond to these proposed regulations. 

### Executive Order 12866 and DOT Regulatory Policies and Procedures 

Executive Order 12866, “Regulatory Planning and Review,” dated September 30, 1993 (58 FR 51736) directs the FAA to assess both the costs and the benefits of a regulatory change. We are not allowed to propose or adopt a regulation unless we make a reasoned determination that the benefits of the intended regulation justify the costs. Our assessment of this rulemaking indicates that its economic impact is minimal because U.S. turbine rotorcraft manufacturers are already manufacturing rotorcraft turbine engines according to European requirements that are equivalent to these proposed requirements. Because the costs and benefits of this action do not make it a “significant regulatory action” as defined in the Order, we have not prepared a “regulatory evaluation,” which is the written cost/benefit analysis ordinarily required for all rulemaking under the DOT Regulatory Policies and Procedures. We do not need to do a full evaluation where the economic impact of a rule is minimal. 

### Economic Evaluation, Regulatory Flexibility Determination, Trade Impact Assessment, and Unfunded Mandates Assessment 

Proposed changes to Federal regulations must undergo several economic analyses. First, Executive Order 12866 directs that each Federal agency propose or adopt a regulation only upon a 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, this Trade Act also requires agencies to consider international standards and, where appropriate, use them as 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 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. 

This proposed rule harmonizes FAA airworthiness standards for the 30-second and 2-minute OEI ratings with similar requirements already adopted by EASA and being processed by Transport Canada. Because the OEI ratings are optional, manufacturers will provide this capability only if they expect to recover any additional costs in the marketplace. The FAA estimates that this rule would affect 8 engine models, approximately 100 helicopters, and that there would be approximately 3 OEI events per year. The total estimated cost of the proposed rule over 20 years is approximately $619,000 in present value cost (in 2005 dollars). These optional costs would only be incurred if the manufacturer believes the enhanced capability benefits exceed the costs. The FAA has not attempted to quantify the cost savings that may accrue due to harmonization of this rule, beyond noting that they contribute to a large potential harmonization savings. Safety after an engine failure or shutdown under this rule would be at least equivalent to operational safety under the previous regulations. 

The FAA finds that the expected outcome of the proposed rule would have a minimal impact with positive net benefits, and, therefore, we did not prepare a full regulatory evaluation. The FAA requests comments with supporting justification about our determination of minimal impact. The FAA has, therefore, determined that this proposed 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. 

### Regulatory Flexibility Act 

The Regulatory Flexibility Act (RFA) of 1980 (Pub. L. 96-354) directs the FAA to fit regulatory requirements to the scale of the businesses, organizations, and governmental jurisdictions subject to the regulation. We are required to determine whether a proposed or final action will have a “significant economic impact on a substantial number of small entities” as they are defined in the Act. If we find the action will have a significant impact, we must do a “regulatory flexibility analysis.” 

However, if an agency determines that a proposed 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. 

                    All U.S. multi-turbine engine rotorcraft manufacturers exceed the Small Business Administration small-entity criteria of 1,500 employees for aircraft manufacturers. Currently manufactured U.S. twin-turbine engine rotorcraft type certificate holders include: Bell Helicopter Textron, Sikorsky Aircraft Corporation, and MD Helicopters, Inc. In addition, all of the U.S. rotorcraft engine manufacturers exceed the Small Business                           ( print page 25212)                        Administration small-entity criteria of 1,000 employees for aircraft engine manufacturers. There are four U.S. engine manufacturers that produce turbine engines for rotorcraft: (1) General Electric, GE Transportation, (2) Rolls-Royce Allison, Allison Engines, Inc., (3) Light Helicopter Turbine Engine Company (a partnership of Rolls-Royce and Honeywell), and (4) Honeywell International, Inc. Given that there are no small-entity manufacturers of twin-engine rotorcraft or of rotorcraft engines and the rule would impose only minimal costs, the FAA certifies that this proposed rule would not have a significant economic impact on a substantial number of small entities. The FAA invites 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 rulemaking and has determined that it uses the European international standards as the regulation basis and is in accord with the Trade Agreements Act. 

### 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 a $100 million or more expenditure (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. The requirements of Title II of the Act, therefore, do not apply. 

### Executive Order 13132, Federalism 

The FAA analyzed this proposed rule under the principles and criteria of Executive Order 13132, Federalism. We have 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 analyzed this NPRM under Executive Order 13211, Actions Concerning Regulations that Significantly Affect Energy Supply, Distribution, or Use (May 18, 2001). We 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. 

# List of Subjects 

### 14 CFR Part 1

      - Air transportation
      - Aircraft
      - Aviation safety
      - Engines
      - Helicopters
      - Ratings
      - Rotorcraft
      - Safety

### 14 CFR Part 33

      - Air transportation
      - Aircraft
      - Aviation safety
      - Engines
      - Ratings
      - Rotorcraft
      - 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 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. 

                        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                        1/2                        -minute OEI power,” to read as follows:                     

§ 1.1 

* * * * *

*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 2                                1/2                                -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 2                            1/2                             minutes each after the failure or shutdown of one engine of a multiengine rotorcraft.                         

* * * * *

      ( print page 25213)    

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

§ 33.5 

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(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. 

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

§ 33.29 

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(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 paragraph (c) of this section must not be capable of being reset in flight. 

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

§ 33.67 

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(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. 

7. Amend § 33.87 by redesignating paragraphs (c)(2), (c)(4), (c)(5), and (c)(6) as paragraphs (c)(4), (c)(5), (c)(6), and (c)(7) respectively, by adding new paragraph (c)(2), and 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: 

§ 33.87 

(a) * * * 

(5) Maximum air bleed for engine and aircraft services must be used during at least one-fifth of the runs, except for the final 120-minute 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. 

(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 final 120-minute 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. 

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(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 4                            1/2                             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 2 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.                         

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                            (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)(7) 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                                   ( print page 25214)                                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:                         

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(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 rating 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. 

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                            (8)                             *Idle.*                             One minute at flight idle.                         

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

§ 33.88 

(a) In addition to the test requirements for the ratings as provided in paragraph (b) of this section, each engine must run for 5 minutes at maximum permissible rpm with the gas temperature at least 75 °F (42 °C) higher than the maximum rating's steady-state operating limit. Following this run, the turbine assembly must be within serviceable limits. 

(b) 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. 

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

§ 33.93 

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(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 

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

# 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. 

(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. The applicant must validate the adequacy of these inspections and maintenance actions; and 

(2) The applicant must establish an in-service engine evaluation program to ensure the continued adequacy of the data for § 33.5(b)(4) pertaining to power availability and the adequacy of the instructions for mandatory post flight inspection and maintenance actions. 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. 

Issued in Washington, DC, on April 13, 2007. 

John J. Hickey, 

Director, Aircraft Certification Service.

 [FR Doc. E7-7943 Filed 5-3-07; 8:45 am] 

BILLING CODE 4910-13-P