[Federal Register Volume 62, Number 50 (Friday, March 14, 1997)] [Proposed Rules] [Pages 12119-12121] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 97-6528] ======================================================================= ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. NM-138, Notice No. SC-97-1-NM] Special Conditions: Jetstream Aircraft Limited Model 4101 Airplane; Continuous Power Reserve (CPR) System AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed special conditions. ----------------------------------------------------------------------- SUMMARY: This notice proposes special conditions for the Jetstream Aircraft Limited Model 4101 airplane. This airplane will have a novel or unusual design feature associated with installation of the CPR system. This notice contains the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the airworthiness standards of part 25 of the FAR. DATES: Comments must be received on or before April 28, 1997. ADDRESSES: Comments on this proposal may be mailed in duplicate to: Federal Aviation Administration, Office of the Assistant Chief Counsel, Attention: Rules Docket (ANM-7), Docket No. NM-138, 1601 Lind Avenue SW, Renton, Washington 98055-4056; or delivered in duplicate to the Office of the Assistant Chief Counsel at the above address. Comments must be marked: Docket No. NM-138. Comments may be inspected in the Rules Docket weekdays, except Federal holidays, between 7:30 a.m. and 4:00 p.m. FOR FURTHER INFORMATION CONTACT: William Schroeder, FAA, Standardization Branch, ANM-113, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue SW, Renton, Washington 98055-4056; telephone 206-227-2148; fax 206-227- 1149. SUPPLEMENTARY INFORMATION: Comments Invited Interested persons are invited to participate in the making of these proposed special conditions by submitting such written data, views, or arguments as they may desire. Communications should identify the regulatory docket or notice number and be submitted in duplicate to the address specified above. All communications received on or before the closing date for comments will be considered by the Administrator before futher rulemaking action on this proposal is taken. The proposals contained in this notice may be changed in light of the comments received. All comments received will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested parties. A report summarizing each substantive public contact with FAA personnel concerning this rulemaking will be filed in the docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must include a self-addressed, stamped postcard on which the following statement is made: [[Page 12120]] ``Comments to Docket No. NM-138.'' The postcard will be date stamped and returned to the commenter. Background On June 7, 1994, Jetstream Aircraft Limited applied for approval of a design change (without a new airplane model designation) to Type Certificate No. A41NM for the installation of a CPR system on the Jetstream Model 4101 airplane. The Jetstream Model 4101 is a 30 passenger, 23,000 pounds maximum take-off weight, transport category airplane with two Allied Signal TPE331-14GR/HR series turbopropeller engines. The CPR system makes a CPR power rating available for the final take-off climb and en route phases of flight after failure of one engine. The CPR power rating for this engine installation is equivalent to the maximum continuous power rating established for the engine under Part 33 of the Federal Aviation Regulations (FAR). Following engine failure, the CPR system automatically increases the engine maximum exhaust gas temperature (EGT) limit, which permits the operating engine's maximum continuous power rating to be obtained at higher ambient air temperatures. Increased engine hour and cycle maintenance factors apply for CPR power rating operation. Since the CPR power rating will only be available during engine-out conditions, the maximum power normally available with all engines operating will be less than the part 33 certified maximum continuous power rating at certain higher ambient temperature ranges. The CPR system is novel when compared to those systems envisaged when the applicable regulations in part 25 were promulgated. Therefore, the airworthiness regulations in part 25 do not contain adequate or appropriate safety standards for airplanes with CPR systems installed. Special conditions are therefore prescribed to supplement the certification basis of record for the Jetstream Model 4101 airplane with a CPR system installed. Type Certification Basis Under the provisions of Sec. 21.101, Jetstream Aircraft Limited must show that the Jetstream Model 4101, as changed, continues to meet the applicable provisions of the regulations incorporated by reference in Type Certificate No. A41NM or the applicable regulations in effect on the date of application for the change. The regulations incorporated by reference in the type certificate are commonly referred to as the ``original type certification basis.'' The regulations incorporated by reference in Type Certificate No. A41NM are part 25 of the FAR dated February 1, 1965, as amended by Amendments 25-1 through 25-66. The regulations incorporated by reference also include certain special conditions, exemptions, and later amended sections of Part 25 that are not relevant to these proposed special conditions. If the regulations incorporated by reference do not provide adequate standards with respect to the change, the applicant must comply with certain regulations in effect on the date of application for the change. The FAA has determined that the areas of the Jetstream Model 4101 that are affected by the installation of the CPR system must also be shown to comply with all sections of part 25 as amended by Amendments 25-1 through 25-81 in effect on the date of application. If the Administrator finds that the applicable airworthiness regulations (i.e., part 25 as amended) do not contain adequate or appropriate safety standards for the Jetstream Model 4101 because of a novel or unusual design feature, special conditions are prescribed under the provisions of Sec. 21.16. When appropriate, special conditions are issued in accordance with Sec. 11.49 of the FAR after public notice, as required by Secs. 11.28 and 11.29(b), and become part of the type certification basis in accordance with Sec. 21.101(b)(2). Special conditions are initially applicable to the model for which they are issued. Should the type certificate for that model be amended later to include any other model that incorporates or should any other model already included on the same type certificate be modified to incorporate the same novel or unusual design feature, the special conditions would also apply to the other model under the provisions of Sec. 21.101(a)(1). In addition to the applicable airworthiness regulations and special conditions, the Jetstream Model 4101 must comply with the fuel vent and exhaust emission requirements of part 34 and the noise certification requirements of part 36. Novel or Unusual Design Features The Jetstream Model 4101 will incorporate a CPR system that provides an engine power rating (as defined on the airplane) that is equivalent to the engine's part 33 certified maximum continuous power rating. Since the CPR power rating will only be available during engine-out conditions, the maximum power available with all engines operating will normally be less than the part 33 certified maximum continuous power rating at certain higher ambient temperatures. The CPR system is integrated into the existing approved Automatic Power Reserve (APR) system. On the Jetstream 4100 airplane, the APR system is equivalent to an Automatic Takeoff Thrust Control System (ATTCS) as defined in Appendix I of Part 25. The currently approved APR system automatically makes additional thermodynamic power and torque available on the operating engine after engine failure during takeoff and for approach climb (go-around). For certain ambient temperature ranges, the proposed CPR system automatically increases the engine's EGT limit and torque available on the operating engine for final take-off climb and en route flight phases after failure of one engine. The CPR-related increased EGT limit, which is above the two-engines-operating EGT maximum continuous power and take-off limits, enables the operating engine to achieve the flat-rated maximum continuous power (torque) level at higher outside air temperature (OAT). Engine operation in the APR and CPR modes requires application of engine hour and cycle maintenance factors as specified in engine Type C Certificate Data Sheet E18NE. As discussed above, these special conditions are applicable to the Jetstream Model 4101. Should Jetstream Aircraft Limited apply at a later date for a change to the type certificate to include another model incorporating the same novel or unusual design feature, these special conditions would apply to that model as well under the provisions of Sec. 21.101(a)(1). Conclusion This action affects only certain novel or unusual design features on one model of airplane. 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 airplane. List of Subjects in 14 CFR Part 25 Air transportation, Aircraft, Aviation safety, Safety. The authority citation for these special conditions is as follows: Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704. The Proposed Special Conditions Accordingly, the Federal Aviation Administration (FAA) proposes the following special conditions as part of the type certification basis for the Jetstream Model 4101 airplane. [[Page 12121]] Installation of a Continuous Power Reserve (CPR) System (a) General. With the CPR system functioning normally as designed, all applicable requirements of part 25 must be met without requiring any unusual action (other than arming the system prior to dispatch) by the crew to set power or thrust. (b) Performance and Reliability Requirements. (1) A CPR failure or combination of failures. (i) That prevents the automatic insertion of CPR thrust or power must be shown to be an improbable event; (ii) That prevents the automatic insertion of APR thrust or power during the critical time interval defined in Appendix I of Part 25 must be shown to be an improbable event; and (iii) Shall not result in the significant loss or reduction in thrust or power, or must be shown to be an extremely improbable event. (2) All applicable performance requirements of part 25 must be met with an engine failure occurring at the most critical time with the CPR system functioning. (c) Thrust Setting. The maximum continuous thrust or power setting specified for use with all engines operating may not be less than any of the following: (1) Ninety (90) percent of the thrust or power set by the CPR system for which AFM performance credit is approved; (2) That required to permit normal operation of all safety-related systems and equipment dependent upon engine thrust or power lever position; or (3) That shown to be free of hazardous engine response characteristics when thrust or power is advanced from the initial all- engines-operating thrust or power setting to the maximum approved maximum continuous/CPR mode thrust or power setting. (d) Powerplant Controls. (1) In addition to the requirements of Sec. 25.1141, no single failure or malfunction, or probable combination thereof, of the CPR, including associated systems, may cause the failure of any powerplant function necessary for safety. (2) The CPR system must be designed to: (i) In the event of a CPR system failure, permit manual decrease or increase in thrust or power up to the highest maximum continuous thrust or power approved for the airplane under existing conditions through the use of the power lever. For airplanes equipped with limiters that automatically prevent engine operating limits from being exceeded under existing ambient conditions, other means may be used to increase the thrust or power in the event of a CFR failure provided the means is located on or forward of the power levers; is easily identified and operated under all operating conditions by a single action of either pilot with the hand that is normally used to actuate the power levels; and meets the requirements of Sec. 25.777 (a),(b), and (c). (ii) Provide a means for the flightcrew to deactivate the automatic CPR function. This means must be designed to prevent inadvertent deactivation. (iii) Provide a means for the flightcrew to verify that the CFR system is in a condition to operate. (e) Powerplant Instruments. In addition to the requirements of Sec. 25.1305, a means must be provided to indicate when the CPR is in the armed or ready condition. Issued in Renton, Washington, on March 6, 1997. Neil D. Schalekamp, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service, ANM-100. [FR Doc. 97-6528 Filed 3-13-97; 8:45 am] BILLING CODE 4910-13-M