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Special Conditions: General Electric Aircraft Engines Model CT7-6E and CT7-8 Turboshaft Engines

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Information about this document as published in the Federal Register.

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AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final special conditions; request for comments.

SUMMARY:

These special conditions are issued for General Electric Aircraft Engines (GEAE) models CT7-6E and CT7-8 turboshaft engines. These engines will have a novel or unusual rated 30-minute power that makes the issue of these special conditions necessary. The existing airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards the Administrator considers to establish a level of safety equivalent to that established by existing airworthiness standards. The rated 30-minute power provides necessary increased rotorcraft hover time to enable operators to better perform critical, life-saving search and rescue missions. For this reason and because a delay would not be in the public interest, the FAA has determined that good cause exists for adopting these special conditions immediately upon publication.

DATES:

The effective date of these special conditions is August 10, 2000. Comments must be received on or before September 11, 2000.

ADDRESSES:

Comments on these special conditions may be mailed in duplicate to: Federal Aviation Administration, Office of the Regional Counsel, Attention: Docket NE122; 12 New England Executive Park, Burlington, Massachusetts 01803-5299, or delivered in duplicate to the Office of the Regional Counsel at the above address. Comments must be marked: Docket No. NE122. Comments may be inspected in the Docket weekdays, except for Federal holidays, between 8 a.m. and 4:30 p.m.

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FOR FURTHER INFORMATION CONTACT:

Mr. Chung Hsieh, 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) 238-7115; Fax (781) 238-7199. If you have access to the Internet, you may also obtain further information by writing to the following Internet address: “chung.hsieh@faa.gov”.

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SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA has determined that good cause exists for making these special conditions effective upon issuance; however, interested persons are invited to submit such written data, views, or arguments as they may desire. Communications should identify the docket number and special conditions number, and be submitted in duplicate to the address specified above, or, if you have access to the internet, you may make a submission to the following Internet address: “chung.hsieh@faa.gov”. All communications received on or before the closing date for comments will be considered by the Administrator. These special conditions may be changed in light of the comments received. All comments submitted will be available in the docket for examination by interested persons, both before and after the closing date for comments. A report summarizing each substantive public contact with FAA personnel concerning this rulemaking will be filed in the docket. Persons wishing the FAA to acknowledge receipt of their comments submitted in response to this request must submit with those comments a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. NE122.” The postcard will be date-stamped and returned to the commenter.

Background

On August 12, 1996, GEAE applied for an amendment to Type Certificate No. E8NE to include new models CT7-6 and CT7-8 turboshaft engines. These models, derivatives of the CT7-6 series turboshaft engine, will include new rated 30-second and 2-minute one-engine-inoperative (OEI) power. On March 10, 2000, GEAE requested an additional rated 30-minute power for models CT7-6E and CT7-8 turboshaft engines. This rating is intended for use after takeoff, for up to 30 minutes at any time between takeoff and landing during any flight when performing search and rescue missions. These engine models will be rated at 30-second OEI, 2-minute OEI, 30-minute OEI, 30-minute, takeoff, and maximum continuous ratings. The existing requirements do not contain a definition for a rated 30-minute power, and do not contain adequate or appropriate safety standards of this new and unusual engine rating.

The rated 30-minute power is the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established under 14 CFR part 33 for periods of use no longer than 30 minutes each. This rating power would provide for rotorcraft hovering operations at a power level greater than maximum continuous power. The certification requirements have been defined around the worst case scenario of unrestricted periods of use up to 30 minutes each in one flight. Therefore, the total accumulated time for endurance testing of 30-minute periods at rated 30-minute power must be 25 hours for certification. However, because the CT7-6E and -8 engine models have a rated 30-minute OEI at higher power and engine limitations than rated 30-minute power, the test run time of 12.5 hours under 33.87(c) may be credited to satisfy one half of the required running time for rated 30-minute power. The additional endurance test runs required for these engine models would therefore be 25 periods of test at rated 30-minute power for 30 minutes each.

Type Certification Basis

Under 14 CFR 21.101, GEAE must show that the models CT7-6E and CT7-8 turboshaft engines meet the requirements of the applicable regulations in effect on the date of the application, or the applicable provisions of the regulations incorporated by reference in Type Certificate No. E8NE. The regulations incorporated by reference in the type certificate are commonly referred to as the “original type certification basis”. Since models CT7-6E and CT7-8 engines are derivatives of the model CT7-6 series turboshaft engine, the regulations incorporated by reference of the engine in Type Certificate No. E8NE are part 33, effective February 1, 1965, as amended by Amendments 33-1 through 33-5; § 33.87, Amendment 12; and Special Conditions Number 33-76-NE-2, Docket No. 16921 (issued October 31, 1978). However, GEAE has elected to demonstrate compliance of later amendments of part 33 for the engines. The certification basis for models CT7-6E and CT7-8 turboshaft engines will be part 33, effective February 1, 1965, as amended by Amendments 33-1 through 33-19; and Special Conditions No. 33-002-SC, Docket No. NE121, published on May 28, 1999 (64 FR 28900).

The Administrator finds that the applicable airworthiness regulations in part 33, as amended, do not contain adequate or appropriate safety standards for the new rated 30-minute power for engine models CT7-6E and CT7-8 Start Printed Page 48888turboshaft engines. Because it is a novel or unusual engine rating feature, special conditions are prescribed under the provisions of 14 CFR 21.16.

Special conditions, as appropriate, are issued in accordance with 14 CFR 11.49 after public notice, as required by §§ 11.28 and 11.29(b), and became part of the type certification basis in accordance with 14 CFR 21.101(b)(2).

Novel or Unusual Design Features

The GEAE engine models CT7-6E and CT7-8 turboshaft engines will incorporate the following novel or unusual design feature: Rated 30-minute power. The power available for rotocrafts hovering to perform search and rescue missions is limited to the maximum continuous rating power under the current part 33 requirements. The proposed rated 30-minute power would provide a higher power level than currently available for use up to 30 minutes at any time between takeoff and landing during any flight. This new rating will enhance rotorcraft safety through the availability of increased power for hovering operations calling for greater than maximum continuous power.

Applicability

As discussed above, these special conditions are applicable to the GEAE models CT7-6E and CT7-8 turboshaft engines. Should GEAE apply at a later date for a change to the type certificate to include another model incorporating the same novel or unusual design feature, the special conditions would apply to that model as well under the provisions of 14 CFR 21.101(a)(1).

Conclusion

This action affects only certain novel or unusual design features on GEAE models CT7-6E and CT7-8 turboshaft engines. It is not a rule of general applicability, and it affects only the applicant who applied to the FAA for approval of these features on the engines.

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List of Subjects in 14 CFR Part 33

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The authority citations for these special conditions is as follows:

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

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The Special Conditions

Accordingly, the Federal Aviation Administration (FAA) proposes the following special conditions as part of the type certification basis for the GEAE models CT7-6E and CT7-8 turboshaft engines:

Instructions for Continued Airworthiness (ICA).

(a) In addition to the requirements of § 33.4, the Instructions for Continued Airworthiness (ICA) procedures must:

(1) Ensure that the engine deterioration in service will not exceed the level shown in certification using the rated 30-minute power.

(2) Be included in the airworthiness limitations section of the ICA.

Engine Ratings and Operating Limitations.

(b) In addition to the ratings provided in § 33.7, a rated 30-minute power is available, which shall be defined as the approved brake horsepower developed under static conditions at specified altitudes and temperatures within the operating limitations established under part 33 of this chapter, and limited in use to periods of not over 30 minutes each.

Endurance Test.

(c) The test requirements of § 33.87(a), (c), and (f), except that the first 35 minutes of the two hour test required by paragraph (c)(3) must be run at rated maximum continuous power for 5 minutes and then at rated 30-minute power for 30 minutes, in each of the 25 six-hour endurance test sequences.

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Issued in Burlington, Massachusetts on August 2, 2000.

David A. Downey,

Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.

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[FR Doc. 00-20272 Filed 8-9-00; 8:45 am]

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