Special Conditions: Gulfstream Aerospace Corporation Model GVII-G500 Series Airplanes; Flight Envelope Protection-High Incidence Protection System, 32759-32764 [2018-15071]

Download as PDF 32759 Rules and Regulations Federal Register Vol. 83, No. 136 Monday, July 16, 2018 This section of the FEDERAL REGISTER contains regulatory documents having general applicability and legal effect, most of which are keyed to and codified in the Code of Federal Regulations, which is published under 50 titles pursuant to 44 U.S.C. 1510. The Code of Federal Regulations is sold by the Superintendent of Documents. NUCLEAR REGULATORY COMMISSION 10 CFR Parts 30, 32, and 35 [NRC–2014–0030] RIN 3150–AI63 Medical Use of Byproduct Material— Medical Event; Definitions and Training and Experience Nuclear Regulatory Commission. ACTION: Final guidance; issuance. AGENCY: The U.S. Nuclear Regulatory Commission (NRC) is issuing a final guidance document entitled, ‘‘Final Guidance for the Rule ‘Medical Use of Byproduct Material—Medical Events Definitions, Training and Experience, and Clarifying Amendments.’ ’’ This guidance document addresses implementation of the NRC’s final rule amending its medical use of byproduct material regulations which is being published concurrently in Separate Part IV of this issue of the Federal Register. DATES: The guidance document is available on July 16, 2018. ADDRESSES: Please refer to Docket ID NRC–2014–0030 when contacting the NRC about the availability of information regarding this document. You may obtain publicly-available information related to this document using any of the following methods: • Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC–2014–0030. Address questions about NRC dockets to Carol Gallagher; telephone: 301–415–3463; email: Carol.Gallagher@nrc.gov. For technical questions, contact the individual listed in the FOR FURTHER INFORMATION CONTACT section of this document. • NRC’s Agencywide Documents Access and Management System (ADAMS): You may obtain publiclyavailable documents online in the ADAMS Public Documents collection at sradovich on DSK3GMQ082PROD with RULES SUMMARY: VerDate Sep<11>2014 16:38 Jul 13, 2018 Jkt 244001 https://www.nrc.gov/reading-rm/ adams.html. To begin the search, select ‘‘ADAMS Public Documents’’ and then select ‘‘Begin Web-based ADAMS Search.’’ For problems with ADAMS, please contact the NRC’s Public Document Room (PDR) reference staff at 1–800–397–4209, 301–415–4737, or by email to pdr.resource@nrc.gov. The final guidance document is available in ADAMS under Accession No. ML18176A377. • NRC’s PDR: You may examine and purchase copies of public documents at the NRC’s PDR, Room O1–F21, One White Flint North, 11555 Rockville Pike, Rockville, Maryland 20852. FOR FURTHER INFORMATION CONTACT: Donna-Beth Howe, Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Washington, DC 20555–0001; telephone: 301–415–5441; email: DonnaBeth.Howe@nrc.gov. SUPPLEMENTARY INFORMATION: The NRC published the draft guidance document in the Federal Register on July 21, 2014 (79 FR 42224). The NRC received seven comments on the draft guidance. The NRC’s response to the public comments received can be found in the fourth section of the final guidance. The guidance document is for use by applicants, licensees, Agreement States, and the NRC staff. This guidance document (ADAMS Accession No. ML18176A377) has four parts: the first two are revisions to existing information in the NUREG–1556, ‘‘Consolidated Guidance About Materials Licenses,’’ series of volumes for medical uses (Volume 9) and commercial nuclear pharmacies (Volume 13); the third part is a series of questions and answers to assist applicants and licensees in understanding and implementing the new regulatory changes; and the fourth is the comments received on the proposed guidance during the public comment period, and the NRC’s responses. The current NUREG–1556 documents provide guidance to applicants for the completion and submission of materials license applications to the NRC. The documents also include model procedures that an applicant may consider when developing its radiation safety program. The guidance document can be found on the NRC’s Medical Uses Licensee Toolkit website (https://www.nrc.gov/ materials/miau/med-use-toolkit.html). PO 00000 Frm 00001 Fmt 4700 Sfmt 4700 The NRC is publishing concurrently with this guidance document the final rule, ‘‘Medical Use of Byproduct Material—Medical Event Definitions, Training and Experience, and Clarifying Amendments’’ (RIN 3150–AI63, NRC– 2008–0175) in Separate Part IV of this issue of the Federal Register. In conjunction with the final rule, the NRC developed this final guidance document which provides guidance to licensees and applicants for implementing the revisions in the final rule. Dated at Rockville, Maryland, this 3rd day of July 2018. For the Nuclear Regulatory Commission. Daniel S. Collins, Director, Division of Materials Safety, Security, State, and Tribal Programs, Office of Nuclear Material Safety and Safeguards. [FR Doc. 2018–14853 Filed 7–13–18; 8:45 am] BILLING CODE 7590–01–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. FAA–2015–0310; Special Conditions No. 25–732–SC] Special Conditions: Gulfstream Aerospace Corporation Model GVII– G500 Series Airplanes; Flight Envelope Protection—High Incidence Protection System Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions. AGENCY: These special conditions are issued for the Gulfstream Aerospace Corporation (Gulfstream) Model GVII– G500 series airplanes. This airplane will have a novel or unusual design feature when compared to the state of technology and design envisioned in the airworthiness standards for transport category airplanes. This design feature is a high incidence protection system that limits the angle of attack at which the airplane can be flown during normal low speed operation. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level SUMMARY: E:\FR\FM\16JYR1.SGM 16JYR1 32760 Federal Register / Vol. 83, No. 136 / Monday, July 16, 2018 / Rules and Regulations of safety equivalent to that established by the existing airworthiness standards. DATES: This action is effective on July 16, 2018. FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, Airframe & Flight Crew Interface Section, AIR–671, Transport Standards Branch, Policy and Innovation Division, Aircraft Certification Service, Federal Aviation Administration, 2200 216th Street, Des Moines, Washington 98198; telephone and fax 206–231–3158; email Joe.Jacobsen@faa.gov. SUPPLEMENTARY INFORMATION: Background On June 30, 2013, Gulfstream Aerospace Corporation (Gulfstream) applied for a type certificate for its new Model GVII–G500 series airplane. The Gulfstream Model GVII–G500 series airplane will be a business jet with seating for up to 19 passengers. It will incorporate a low, swept-wing design with a T-tail. The powerplant will consist of two aft-fuselage-mounted turbofan engines. The Gulfstream Model GVII–G500 series airplane’s maximum takeoff weight will be approximately 79,600 pounds. The high incidence protection system prevents the airplane from stalling at low speeds and, therefore, a stall warning system is not needed during normal flight conditions. sradovich on DSK3GMQ082PROD with RULES Type Certification Basis Under the provisions of title 14, Code of Federal Regulations (14 CFR) 21.17, Gulfstream must show that the Model GVII–G500 series airplane meets the applicable provisions of 14 CFR part 25, as amended by amendments 25–1 through 25–137. If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for the Gulfstream Model GVII–G500 series airplane because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16. 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 the same novel or unusual design feature, these special conditions would also apply to the other model under § 21.101. In addition to the applicable airworthiness regulations and special conditions, the Gulfstream Model GVII– G500 series airplane must comply with the fuel vent and exhaust emission VerDate Sep<11>2014 16:38 Jul 13, 2018 Jkt 244001 requirements of 14 CFR part 34, and the noise certification requirements of 14 CFR part 36. The FAA issues special conditions, as defined in 14 CFR 11.19, in accordance with § 11.38, and they become part of the type certification basis under § 21.17(a)(2). Novel or Unusual Design Features The Gulfstream Model GVII–G500 series airplane will incorporate the following novel or unusual design feature: A high incidence protection system, which limits the angle of attack at which the airplane can be flown during normal low speed operation, prohibits the airplane from stalling, and cannot be overridden by the flightcrew. The application of this angle of attack limit influences the stall speed determination, stall characteristics, stall warning demonstration, and longitudinal handling characteristics of the airplane. Existing airworthiness regulations do not contain adequate standards to address this feature. Discussion The high incidence protection system prevents the airplane from stalling at low speeds and, therefore, a stall warning system is not needed during normal flight conditions. However, during failures, which are not shown to be extremely improbable, the requirements of §§ 25.203 and 25.207 apply, although slightly modified by these conditions. If there are failures of the high incidence protection system that are not shown to be extremely improbable, the flight characteristics at the angle of attack for CLMAX must be suitable in the traditional sense, and stall warning must be provided in a conventional manner. Part I of the special conditions is in lieu of §§ 25.21(b), 25.103, 25.145(a), 25.145(b)(6), 25.175(c) and (d), 25.201, 25.203, 25.207, and 25.1323(d). Part II is in lieu of §§ 25.21(g)(1), 25.105(a)(2)(i), 25.107(c) and (g), 25.121(b)(2)(ii)(A), 25.121(c)(2)(ii)(A), 25.121(d)(2)(ii), 25.123(b)(2)(i), 25.125(b)(2)(ii)(B), and 25.143(j). These special conditions address this novel or unusual design feature on the Gulfstream Model GVII–G500 series airplane, and contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards. These special conditions are different from special conditions previously issued on this topic. In Part I, sections 3.b.iv, 3.b.vi, 3.e.vi, 5.a.i.1, 5.a.i.4, 5.a.i.6, 5.a.i.7, 5.c.i.4, 5.c.i.5, 5.c.i.6, PO 00000 Frm 00002 Fmt 4700 Sfmt 4700 5.c.ii.4, and 5.c.ii.5, previously used verbiage was updated to reflect language recommended in the Aviation Rulemaking Advisory Committee (ARAC) Flight Test Harmonization Working Group (FTHWG) Phase 2 report. This language more accurately describes the actions required and formulas to be used to obtain the required result. In Part I, sections 3.b.ii and 5.a.ii.4, the ARAC FTHWG language was adapted to reflect specific Gulfstream design features. In several previous special conditions on this subject, we used the nomenclature VCLMAX. To avoid confusion with previous Gulfstream special conditions, we have changed the nomenclature to VCLMAX Demo to highlight a difference. The difference is not significant, but the change in nomenclature was considered clarifying and therefore was adopted in this instance. Discussion of Comments The FAA issued Notice of Proposed Special Conditions No. 25–18–02–SC for the Gulfstream Model GVII–G500 series airplane, which was published in the Federal Register on May 14, 2018 (83 FR 22214). The FAA received one comment that was not relevant to the subject of these special conditions. Therefore, the special conditions are adopted as proposed. Applicability As discussed above, these special conditions are applicable to the Gulfstream Model GVII–G500 series airplane. Should Gulfstream 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 standard practice, the effective date of final special conditions would be 30 days after the date of publication in the Federal Register. However, as the certification date for the Gulfstream Model GVII–G500 series airplane is imminent, the FAA finds that good cause exists to make these special conditions effective upon publication. Conclusion This action affects only certain novel or unusual design features on Gulfstream Model GVII–G500 series of airplanes. It is not a rule of general applicability. List of Subjects in 14 CFR Part 25 Aircraft, Aviation safety, Reporting and recordkeeping requirements. E:\FR\FM\16JYR1.SGM 16JYR1 Federal Register / Vol. 83, No. 136 / Monday, July 16, 2018 / Rules and Regulations Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702, 44704. The Special Conditions Accordingly, pursuant to the authority delegated to me by the Administrator, the following special conditions are issued as part of the type certification basis for Gulfstream Model GVII–G500 series airplanes. ■ Part I: Stall Protection and Scheduled Operating Speeds In the following sections, ‘‘in icing conditions,’’ means with ice accretions (relative to the relevant flight phase) as defined in appendix C to part 25, at amendment 25–121. 1. Definitions These special conditions use terminology that does not appear in 14 CFR part 25. For the purpose of these special conditions, the following terms describe certain aspects of this novel or unusual design feature: High-Incidence Protection System A system that operates directly and automatically on the airplane’s flight controls to limit the maximum angle of attack that can be attained to a value below that at which an aerodynamic stall would occur. Alpha-Limit The maximum angle of attack at which an airplane stabilizes with the high incidence protection system operating and the longitudinal control held on its aft stop. VMIN The minimum steady flight speed in the airplane’s configuration under consideration with the high incidence protection system operating. See Part I, Section 3, ‘‘Minimum Steady Flight Speed and Reference Stall Speed,’’ of these special conditions. sradovich on DSK3GMQ082PROD with RULES VMIN1g VMIN corrected to 1g acceleration of gravity conditions. See Part I, Section 3, ‘‘Minimum Steady Flight Speed and Reference Stall Speed,’’ of these special conditions. This is the minimum calibrated airspeed at which the airplane can develop a lift force normal to the flight path and equal to its weight when at an angle of attack not greater than that determined for VMIN. VerDate Sep<11>2014 16:38 Jul 13, 2018 Jkt 244001 The applicant must establish the capability and reliability of the high incidence protection system. The applicant may establish this capability and reliability by flight testing, simulation, or analysis as appropriate. The capability and reliability required are: a. It must not be possible to encounter a stall during the pilot-induced maneuvers required by Part I, section 5(a), ‘‘High Incidence Handling Demonstrations,’’ and the handling characteristics must be acceptable as required by Part I, section 5(b), ‘‘Characteristics in High Incidence Maneuvers’’ of these special conditions; b. The airplane must be protected against stalling due to the effects of wind shears and gusts at low speeds as required by Section 6, ‘‘Atmospheric Disturbances’’ of these special conditions; c. The ability of the high incidence protection system to accommodate any reduction in stalling incidence must be verified in icing conditions; d. The high incidence protection system must be provided in each abnormal configuration of the high lift devices that is likely to be used in flight following system failures; and e. The reliability of the system and the effects of failures must be acceptable in accordance with § 25.1309. 3. Minimum Steady Flight Speed and Reference Stall Speed In lieu of § 25.103, ‘‘Stall speed,’’ the following applies: a. The minimum steady flight speed, VMIN, is the final, stabilized, calibrated airspeed obtained when an airplane is decelerated until the longitudinal control is on its stop in such a way that the entry rate does not exceed 1 knot per second. b. The minimum steady flight speed, VMIN, must be determined in icing and non-icing conditions with: i. The high incidence protection system operating normally; ii. Idle thrust; iii. All combinations of flap settings and landing gear positions for which VMIN is required to be determined; iv. The weight used when the reference stall speed, VSR, is used as a factor to determine compliance with a required performance standard; v. The most unfavorable center of gravity (CG) allowable; and vi. The airplane trimmed for straight flight at a speed selected by the applicant, but not less than 1.13 VSR and not greater than 1.3 VSR. PO 00000 Frm 00003 Fmt 4700 Sfmt 4700 Where: VCLMAX Demo = Demonstrated calibrated airspeed obtained when the corrected lift coefficient of the load factor is first a maximum during the maneuver prescribed in section 3(e)(viii) of this special condition. nZW = Load factor normal to the flight path at VCLMAX Demo W = Airplane gross weight; S = Aerodynamic reference wing area; and q = Dynamic pressure. e. VCLMAX Demo is determined in nonicing conditions with: i. Engines idling, or, if that resultant thrust causes an appreciable decrease in stall speed, not more than zero thrust at the stall speed; ii. The airplane in other respects (such as flaps and landing gear) in the condition existing in the test or performance standard in which VSR is being used; iii. The weight used when VSR is being used as a factor to determine compliance with a required performance standard; iv. The CG position that results in the highest value of the reference stall speed; v. The airplane trimmed for straight flight at a speed selected by the applicant, but not less than 1.13 VSR and not greater than 1.3 VSR; vi. At the option of the applicant, the high incidence protection system can be disabled or adjusted to allow full development of the maneuver to the angle of attack corresponding to VSR; and vii. Starting from the stabilized trim condition, with an application of the longitudinal control to decelerate the airplane so that the speed reduction does not exceed 1 knot per second. E:\FR\FM\16JYR1.SGM 16JYR1 ER16JY18.013</GPH> The authority citation for these special conditions is as follows: c. The 1g minimum steady flight speed, VMIN1g, is the minimum calibrated airspeed at which an airplane can develop a lift force (normal to the flight path) equal to its weight, while at an angle of attack not greater than that at which the minimum steady flight speed referenced in section 3(a) of this special condition is determined. These minimum calibrated airspeeds must be determined for both icing and non-icing conditions. d. The reference stall speed, VSR, is a calibrated airspeed defined by the applicant. VSR may not be less than a 1g stall speed. VSR must be determined in non-icing conditions and expressed as: ER16JY18.012</GPH> 2. Capability and Reliability of the High Incidence Protection System Authority Citation 32761 32762 Federal Register / Vol. 83, No. 136 / Monday, July 16, 2018 / Rules and Regulations 4. Stall Warning In lieu of § 25.207, the following apply: a. Normal Operation If the design meets all conditions of Part I, section 2 of these special conditions, then the airplane need not provide stall warning during normal operation. The conditions of Part I, section 2 provide a level of safety equal to the intent of § 25.207, ‘‘Stall warning,’’ so the provision of an additional, unique warning device for normal operations is not required. sradovich on DSK3GMQ082PROD with RULES b. High Incidence Protection System Failure For any failures of the high incidence protection system that the applicant cannot show to be extremely improbable, and that result in the capability of the system no longer satisfying any part of sections 2(a), (b), and (c) of Part I of these special conditions: The design must provide stall warning that protects against encountering unacceptable characteristics and against encountering stall. i. This stall warning, with the flaps and landing gear in any normal position, must be clear and distinctive to the pilot, and must meet the requirements specified in sections 4(b)(iv) and 4(b)(v) of Part I of these special conditions. ii. The design must also provide this stall warning in each abnormal configuration of the high lift devices that is likely to be used in flight following system failures. iii. The design may furnish this stall warning either through the inherent aerodynamic qualities of the airplane or by a device that will provide clearly distinguishable indications to the flightcrew under all expected conditions of flight. However, a visual stall warning device that requires the attention of the flightcrew within the flight deck is not acceptable by itself. If a warning device is used, it must provide a warning in each of the airplane configurations prescribed in section 4(b)(i), above, and for the conditions prescribed in sections 4(b)(iv) and 4(b)(v) of part I of these special conditions. iv. In non-icing conditions, the stall warning must provide sufficient margin to prevent encountering unacceptable characteristics and encountering stall in the following conditions: 1. In power-off straight deceleration not exceeding 1 knot per second to a speed of 5 knots or 5 percent calibrated airspeed (CAS), whichever is greater, below the warning onset; and VerDate Sep<11>2014 16:38 Jul 13, 2018 Jkt 244001 2. In turning flight, stall deceleration at entry rates up to 3 knots per second when recovery is initiated not less than 1 second after the warning onset. v. In icing conditions, the stall warning must provide sufficient margin to prevent encountering unacceptable characteristics and encountering stall in power-off straight and turning flight decelerations not exceeding 1 knot per second, when the pilot starts a recovery maneuver not less than three seconds after the onset of stall warning. vi. An airplane is considered stalled when the behavior of the airplane gives the pilot a clear, distinctive, and acceptable indication that the airplane is stalled. Acceptable indications of a stall, occurring either individually or in combination, are: 1. A nose-down pitch that cannot be readily arrested; 2. Buffeting of a magnitude and severity that is strong and thereby an effective deterrent to further speed reduction; or 3. The pitch control reaches the aft stop, and no further increase in pitch attitude occurs when the control is held full aft for a short time before recovery is initiated. vii. An airplane exhibits unacceptable characteristics during straight or turning flight decelerations if it is not always possible to produce and to correct roll and yaw by unreversed use of aileron and rudder controls, or abnormal noseup pitching occurs. 5. Handling Characteristics at High Incidence a. High Incidence Handling Demonstrations In lieu of § 25.201, ‘‘Stall demonstration,’’ the following is required: i. Maneuvers to the limit of the longitudinal control, in the nose-up sense, must be demonstrated in straight flight and in 30-degree banked turns with: 1. The high incidence protection system operating normally; 2. Initial power conditions of: a. Power off; and b. Power necessary to maintain level flight at 1.5 VSR1, where VSR1 is the reference stall speed with flaps in approach position, landing gear retracted, and maximum landing weight; 3. None; 4. Flaps, landing gear, and deceleration devices in any likely combination of positions not prohibited by the airplane flight manual (AFM); 5. Representative weights within the range for which certification is requested; PO 00000 Frm 00004 Fmt 4700 Sfmt 4700 6. The most adverse CG for recovery; and 7. The airplane trimmed for straight flight at the speed prescribed in section 3(e)(v) of these special conditions. ii. The following procedures must be used to show compliance in non-icing and icing conditions: 1. Starting at a speed sufficiently above the minimum steady flight speed to ensure that a steady rate of speed reduction can be established, apply the longitudinal control so that the speed reduction does not exceed 1 knot per second until the control reaches the stop. 2. The longitudinal control must be maintained at the stop until the airplane has reached a stabilized flight condition, and must then be recovered by normal recovery techniques. 3. Maneuvers with increased deceleration rates: a. In non-icing conditions, the requirements must also be met with increased rates of entry to the incidence limit, up to the maximum rate achievable. b. In icing conditions, with the antiice system working normally, the requirements must also be met with increased rates of entry to the incidence limit, up to three knots per second. 4. Maneuvers with ice accretion prior to normal operation of the ice protection system: For flight in icing conditions before the ice protection system has been activated and is performing its intended function, the handling demonstration requirements identified in section 5(a)(i) must be satisfied using the procedures specified in sections 5(a)(ii)(1) and 5(a)(ii)(2) of these special conditions. The airplane configurations required to be tested must be in accordance with the limitations and procedures for operating the ice protection system provided in the AFM, per § 25.21(g)(1), as modified by and Part II of these special conditions. b. Characteristics in High Incidence Maneuvers In lieu of § 25.203, ‘‘Stall characteristics,’’ the following apply: i. Throughout maneuvers with a rate of deceleration of not more than 1 knot per second, both in straight flight and in 30-degree banked turns, the airplane’s characteristics must be as follows: 1. There must not be any abnormal nose-up pitching; 2. There must not be any uncommanded nose-down pitching, which would be indicative of stall. However, reasonable attitude changes associated with stabilizing the incidence at Alpha limit, as the longitudinal E:\FR\FM\16JYR1.SGM 16JYR1 Federal Register / Vol. 83, No. 136 / Monday, July 16, 2018 / Rules and Regulations control reaches the stop would be acceptable; 3. There must not be any uncommanded lateral or directional motion, and the pilot must retain good lateral and directional control by conventional use of the controls throughout the maneuver; and 4. The airplane must not exhibit buffeting of a magnitude and severity that would act as a deterrent from completing the maneuver specified in section 5(a)(i) of these special conditions. ii. In maneuvers with increased rates of deceleration, some degradation of characteristics is acceptable, associated with a transient excursion beyond the stabilized Alpha limit. However, the airplane must not exhibit dangerous characteristics or characteristics that would deter the pilot from holding the longitudinal control on the stop for a period of time appropriate to the maneuver. iii. It must always be possible for flightcrew to reduce incidence by conventional use of the controls. iv. The rate at which the airplane can be maneuvered from trim speeds, associated with scheduled operating speeds such as V2 and VREF up to Alpha limit, must not be unduly damped or be significantly slower than can be achieved on conventionally controlled transport airplanes. sradovich on DSK3GMQ082PROD with RULES c. Characteristics up to the Maximum Lift Angle of Attack In addition to the requirements in section 5(b) of this special condition, the following requirements apply: i. In non-icing conditions, maneuvers with a rate of deceleration of not more than 1 knot per second, up to the angle of attack corresponding to VSR obtained using sections 3(d) and (e) of this special condition, must be demonstrated in straight flight and in 30-degree banked turns in the following configurations: 1. The high incidence protection system deactivated or adjusted, at the option of the applicant, to allow higher incidence than is possible with the normal production system; 2. Automatic-thrust-increase system inhibited (if applicable); 3. Engines idling; 4. Flaps, landing gear, and deceleration devices in any likely combination of positions not prohibited by the AFM; 5. The most adverse CG for recovery; and 6. The airplane trimmed for straight flight at the speed prescribed in section 3(e)(v) of this special condition. VerDate Sep<11>2014 16:38 Jul 13, 2018 Jkt 244001 ii. In icing conditions, maneuvers with a rate of deceleration of not more than 1 knot per second up to the maximum angle of attack reached during maneuvers from section 5(a)(ii)(3)(b) must be demonstrated in straight flight with: 1. The high incidence protection system deactivated or adjusted, at the option of the applicant, to allow higher incidence than is possible with the normal production system; 2. Automatic-thrust-increase system inhibited (if applicable); 3. Engines idling; 4. Flaps, landing gear, and deceleration devices in any likely combination of positions not prohibited by the AFM; 5. The most adverse CG for recovery; and 6. The airplane trimmed for straight flight at the speed prescribed in section 3(e)(v) of this special condition. iii. During the maneuvers used to show compliance with sections 5(c)(i) and 5(c)(ii) of Part I of these special conditions, the airplane must not exhibit dangerous characteristics and it must always be possible for flightcrew to reduce angle of attack by conventional use of the controls. The pilot must retain good lateral and directional control, by conventional use of the controls, throughout the maneuver. 6. Atmospheric Disturbances Operation of the high incidence protection system must not adversely affect airplane control during expected levels of atmospheric disturbances, nor impede the application of recovery procedures in case of wind shear. This must be demonstrated in non-icing and icing conditions. 7. None 8. Proof of Compliance Add the following requirement to that of § 25.21: (b) The flying qualities will be evaluated at the most unfavorable CG position. 9. The Design Must Meet the Following Modified Requirements 14 CFR section Change 25.145(a) ......... ‘‘VMIN’’ in lieu of ‘‘stall identification.’’ ‘‘VMIN’’ in lieu of ‘‘VSW.’’ ‘‘VMIN’’ in lieu of ‘‘VSW.’’ 25.145(b)(6) ..... 25.175(c) and (d). 25.1323(d) ....... PO 00000 Frm 00005 ‘‘From 1.23 VSR to VMIN’’ in lieu of ‘‘From 1.23 VSR to the speed at which stall warning begins;’’ and ‘‘speeds below VMIN’’ in lieu of ‘‘speeds below stall warning speed.’’ Fmt 4700 Sfmt 4700 32763 Part II: Credit for Robust Envelope Protection in Icing Conditions 1. In lieu of § 25.21(g)(1), the following applies: (g) The requirements of this subpart associated with icing conditions apply only if certification for flight in icing conditions is desired. If certification for flight in icing conditions is desired, the following requirements also apply (see AC 25–25): (1) Each requirement of this subpart, except §§ 25.121(a), 25.123(c), 25.143(b)(1) and (b)(2), 25.149, 25.201(c)(2), 25.207(c) and (d), and 25.251(b) through (e), must be met in icing conditions. Compliance must be shown using the ice accretions defined in appendix C to part 25, assuming normal operation of the airplane and its ice protection system in accordance with the operating limitations and operating procedures established by the applicant and provided in the airplane flight manual. 2. In lieu of § 25.103, ‘‘Stall speed,’’ define the stall speed as provided in Special Conditions Part I, section 3, ‘‘Minimum Steady Flight Speed and Reference Stall Speed.’’ 3. In lieu of § 25.105(a)(2)(i) to read as follows: (2) In icing conditions, if in the configuration of § 25.121(b) with the ‘‘Takeoff Ice’’ accretion defined in appendix C to part 25: (i) The V2 speed scheduled in nonicing conditions does not provide the maneuvering capability specified in § 25.143(h) for the takeoff configuration, or 4. In lieu of § 25.107(c) and (g), the following apply, with additional sections (c’) and (g’): (c) In non-icing conditions, V2, in terms of calibrated airspeed, must be selected by the applicant to provide at least the gradient of climb required by § 25.121(b) but may not be less than— 1. V2MIN; 2. VR plus the speed increment attained (in accordance with § 25.111(c)(2)) before reaching a height of 35 feet above the takeoff surface; and 3. A speed that provides the maneuvering capability specified in § 25.143(h). (c’) In icing conditions with the ‘‘Takeoff Ice’’ accretion defined in appendix C to part 25, V2 may not be less than— 1. The V2 speed determined in nonicing conditions. 2. A speed that provides the maneuvering capability specified in § 25.143(h). (g) In non-icing conditions, VFTO, in terms of calibrated airspeed, must be E:\FR\FM\16JYR1.SGM 16JYR1 sradovich on DSK3GMQ082PROD with RULES 32764 Federal Register / Vol. 83, No. 136 / Monday, July 16, 2018 / Rules and Regulations selected by the applicant to provide at least the gradient of climb required by § 25.121(c), but may not be less than— 1. 1.18 VSR; and 2. A speed that provides the maneuvering capability specified in § 25.143(h). (g’) In icing conditions with the ‘‘Final Takeoff Ice’’ accretion defined in appendix C to part 25, VFTO may not be less than— 1. The VFTO speed determined in nonicing conditions. 2. A speed that provides the maneuvering capability specified in § 25.143(h). 5. In lieu of §§ 25.121(b)(2)(ii)(A), 25.121(c)(2)(ii)(A), and 25.121(d)(2)(ii), the following apply: § 25.121 Climb: one-engine inoperative: (b) Takeoff; landing gear retracted. In the takeoff configuration existing at the point of the flight path at which the landing gear is fully retracted, and in the configuration used in § 25.111, but without ground effect, * * * * * 2. The requirements of subparagraph (b)(1) of this section must be met: * * * * * (ii) In icing conditions with the ‘‘Takeoff Ice’’ accretion defined in appendix C of part 25, if in the configuration of § 25.121(b) with the ‘‘Takeoff Ice’’ accretion: (A) The V2 speed scheduled in nonicing conditions does not provide the maneuvering capability specified in § 25.143(h) for the takeoff configuration; or (c) Final takeoff. In the en route configuration at the end of the takeoff path determined in accordance with § 25.111: * * * * * 2. The requirements of subparagraph (c)(1) of this section must be met: * * * * * (ii) In icing conditions with the ‘‘Final Takeoff Ice’’ accretion defined in appendix C of part 25, if: (A) The VFTO speed scheduled in nonicing conditions does not provide the maneuvering capability specified in § 25.143(h) for the en route configuration; or (d) Approach. In a configuration corresponding to the normal all-engines operating procedure in which VSR for this configuration does not exceed 110 percent of the VSR for the related allengines-operating landing configuration: * * * * * 2. The requirements of sub-paragraph (d)(1) of this section must be met: * * * * * VerDate Sep<11>2014 16:38 Jul 13, 2018 Jkt 244001 (ii) In icing conditions with the ‘‘Approach Ice’’ accretion defined in appendix C to part 25, in a configuration corresponding to the normal all-enginesoperating procedure in which VMIN1g for this configuration does not exceed 110% of the VMIN1g for the related all engines-operating landing configuration in icing, with a climb speed established with normal landing procedures, but not more than 1.4 VSR (VSR determined in non-icing conditions). 6. In lieu of § 25.123 (b)(2)(i), the following applies: § 25.123 En route flight paths: (b) The one-engine-inoperative net flight path data must represent the actual climb performance diminished by a gradient of climb of 1.1 percent for two-engine airplanes, 1.4 percent for three-engine airplanes, and 1.6 percent for four-engine airplanes. * * * * * 2. In icing conditions with the ‘‘En route Ice’’ accretion defined in appendix C to part 25 if: (i) The minimum en route speed scheduled in non-icing conditions does not provide the maneuvering capability specified in § 25.143(h) for the en route configuration, or 7. In lieu of § 25.125(b)(2)(ii)(B) and § 25.125(b)(2)(ii)(C), the following applies: § 25.125 Landing (b) In determining the distance in (a): * * * * * 2. A stabilized approach, with a calibrated airspeed of not less than VREF, must be maintained down to the 50-foot height. * * * * * (ii) In icing conditions, VREF may not be less than: (A) The speed determined in subparagraph (b)(2)(i) of this section; (B) A speed that provides the maneuvering capability specified in § 25.143(h) with the ‘‘Landing Ice’’ accretion defined in appendix C to part 25. 8. In lieu of § 25.143(j), the following applies: § 25.143 General (j) For flight in icing conditions— before the ice protection system has been activated and is performing its intended function—the following requirements apply: (1) If activating the ice protection system depends on the pilot seeing a specified ice accretion on a reference surface (not just the first indication of icing), the requirements of § 25.143 apply with the ice accretion defined in part II(e) of appendix C to part 25. (2) For other means of activating the ice protection system, it must be PO 00000 Frm 00006 Fmt 4700 Sfmt 4700 demonstrated in flight with the ice accretion defined in part II(e) of appendix C to part 25 that: (i) The airplane is controllable in a pull-up maneuver up to 1.5 g load factor or lower if limited by AOA protection; and (ii) There is no reversal of pitch control force during a pushover maneuver down to 0.5 g load factor. 9. In lieu of § 25.207, ‘‘Stall warning,’’ to read as the requirements defined in Part I of these special conditions. Issued in Des Moines, Washington, on July 9, 2018. Victor Wicklund, Manager, Transport Standards Branch, Policy and Innovation Division, Aircraft Certification Service. [FR Doc. 2018–15071 Filed 7–13–18; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 97 [Docket No. 31203; Amdt. No. 3808] Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures; Miscellaneous Amendments Federal Aviation Administration (FAA), DOT. ACTION: Final rule. AGENCY: This rule amends, suspends, or removes Standard Instrument Approach Procedures (SIAPs) and associated Takeoff Minimums and Obstacle Departure Procedures for operations at certain airports. These regulatory actions are needed because of the adoption of new or revised criteria, or because of changes occurring in the National Airspace System, such as the commissioning of new navigational facilities, adding new obstacles, or changing air traffic requirements. These changes are designed to provide for the safe and efficient use of the navigable airspace and to promote safe flight operations under instrument flight rules at the affected airports. DATES: This rule is effective July 16, 2018. The compliance date for each SIAP, associated Takeoff Minimums, and ODP is specified in the amendatory provisions. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of July 16, 2018. SUMMARY: E:\FR\FM\16JYR1.SGM 16JYR1

Agencies

[Federal Register Volume 83, Number 136 (Monday, July 16, 2018)]
[Rules and Regulations]
[Pages 32759-32764]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-15071]


=======================================================================
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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2015-0310; Special Conditions No. 25-732-SC]


Special Conditions: Gulfstream Aerospace Corporation Model GVII-
G500 Series Airplanes; Flight Envelope Protection--High Incidence 
Protection System

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

-----------------------------------------------------------------------

SUMMARY: These special conditions are issued for the Gulfstream 
Aerospace Corporation (Gulfstream) Model GVII-G500 series airplanes. 
This airplane will have a novel or unusual design feature when compared 
to the state of technology and design envisioned in the airworthiness 
standards for transport category airplanes. This design feature is a 
high incidence protection system that limits the angle of attack at 
which the airplane can be flown during normal low speed operation. The 
applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for this design feature. These special 
conditions contain the additional safety standards that the 
Administrator considers necessary to establish a level

[[Page 32760]]

of safety equivalent to that established by the existing airworthiness 
standards.

DATES: This action is effective on July 16, 2018.

FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, Airframe & Flight Crew 
Interface Section, AIR-671, Transport Standards Branch, Policy and 
Innovation Division, Aircraft Certification Service, Federal Aviation 
Administration, 2200 216th Street, Des Moines, Washington 98198; 
telephone and fax 206-231-3158; email [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    On June 30, 2013, Gulfstream Aerospace Corporation (Gulfstream) 
applied for a type certificate for its new Model GVII-G500 series 
airplane. The Gulfstream Model GVII-G500 series airplane will be a 
business jet with seating for up to 19 passengers. It will incorporate 
a low, swept-wing design with a T-tail. The powerplant will consist of 
two aft-fuselage-mounted turbofan engines. The Gulfstream Model GVII-
G500 series airplane's maximum takeoff weight will be approximately 
79,600 pounds.
    The high incidence protection system prevents the airplane from 
stalling at low speeds and, therefore, a stall warning system is not 
needed during normal flight conditions.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.17, Gulfstream must show that the Model GVII-G500 series 
airplane meets the applicable provisions of 14 CFR part 25, as amended 
by amendments 25-1 through 25-137.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Gulfstream Model GVII-G500 series 
airplane because of a novel or unusual design feature, special 
conditions are prescribed under the provisions of Sec.  21.16.
    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 the same novel or 
unusual design feature, these special conditions would also apply to 
the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Gulfstream Model GVII-G500 series airplane must comply 
with the fuel vent and exhaust emission requirements of 14 CFR part 34, 
and the noise certification requirements of 14 CFR part 36.
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The Gulfstream Model GVII-G500 series airplane will incorporate the 
following novel or unusual design feature:
    A high incidence protection system, which limits the angle of 
attack at which the airplane can be flown during normal low speed 
operation, prohibits the airplane from stalling, and cannot be 
overridden by the flightcrew. The application of this angle of attack 
limit influences the stall speed determination, stall characteristics, 
stall warning demonstration, and longitudinal handling characteristics 
of the airplane. Existing airworthiness regulations do not contain 
adequate standards to address this feature.

Discussion

    The high incidence protection system prevents the airplane from 
stalling at low speeds and, therefore, a stall warning system is not 
needed during normal flight conditions. However, during failures, which 
are not shown to be extremely improbable, the requirements of 
Sec. Sec.  25.203 and 25.207 apply, although slightly modified by these 
conditions. If there are failures of the high incidence protection 
system that are not shown to be extremely improbable, the flight 
characteristics at the angle of attack for CLMAX must be 
suitable in the traditional sense, and stall warning must be provided 
in a conventional manner.
    Part I of the special conditions is in lieu of Sec. Sec.  25.21(b), 
25.103, 25.145(a), 25.145(b)(6), 25.175(c) and (d), 25.201, 25.203, 
25.207, and 25.1323(d). Part II is in lieu of Sec. Sec.  25.21(g)(1), 
25.105(a)(2)(i), 25.107(c) and (g), 25.121(b)(2)(ii)(A), 
25.121(c)(2)(ii)(A), 25.121(d)(2)(ii), 25.123(b)(2)(i), 
25.125(b)(2)(ii)(B), and 25.143(j).
    These special conditions address this novel or unusual design 
feature on the Gulfstream Model GVII-G500 series airplane, and contain 
the additional safety standards that the Administrator considers 
necessary to establish a level of safety equivalent to that established 
by the existing airworthiness standards.
    These special conditions are different from special conditions 
previously issued on this topic. In Part I, sections 3.b.iv, 3.b.vi, 
3.e.vi, 5.a.i.1, 5.a.i.4, 5.a.i.6, 5.a.i.7, 5.c.i.4, 5.c.i.5, 5.c.i.6, 
5.c.ii.4, and 5.c.ii.5, previously used verbiage was updated to reflect 
language recommended in the Aviation Rulemaking Advisory Committee 
(ARAC) Flight Test Harmonization Working Group (FTHWG) Phase 2 report. 
This language more accurately describes the actions required and 
formulas to be used to obtain the required result. In Part I, sections 
3.b.ii and 5.a.ii.4, the ARAC FTHWG language was adapted to reflect 
specific Gulfstream design features.
    In several previous special conditions on this subject, we used the 
nomenclature VCLMAX. To avoid confusion with previous 
Gulfstream special conditions, we have changed the nomenclature to 
VCLMAX Demo to highlight a difference. The difference is not 
significant, but the change in nomenclature was considered clarifying 
and therefore was adopted in this instance.

Discussion of Comments

    The FAA issued Notice of Proposed Special Conditions No. 25-18-02-
SC for the Gulfstream Model GVII-G500 series airplane, which was 
published in the Federal Register on May 14, 2018 (83 FR 22214). The 
FAA received one comment that was not relevant to the subject of these 
special conditions. Therefore, the special conditions are adopted as 
proposed.

Applicability

    As discussed above, these special conditions are applicable to the 
Gulfstream Model GVII-G500 series airplane. Should Gulfstream 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 standard practice, the effective date of final special 
conditions would be 30 days after the date of publication in the 
Federal Register. However, as the certification date for the Gulfstream 
Model GVII-G500 series airplane is imminent, the FAA finds that good 
cause exists to make these special conditions effective upon 
publication.

Conclusion

    This action affects only certain novel or unusual design features 
on Gulfstream Model GVII-G500 series of airplanes. It is not a rule of 
general applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

[[Page 32761]]

Authority Citation

    The authority citation for these special conditions is as follows:

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

The Special Conditions

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Gulfstream Model GVII-G500 series 
airplanes.

Part I: Stall Protection and Scheduled Operating Speeds

    In the following sections, ``in icing conditions,'' means with ice 
accretions (relative to the relevant flight phase) as defined in 
appendix C to part 25, at amendment 25-121.
1. Definitions
    These special conditions use terminology that does not appear in 14 
CFR part 25. For the purpose of these special conditions, the following 
terms describe certain aspects of this novel or unusual design feature:

High-Incidence Protection System

    A system that operates directly and automatically on the airplane's 
flight controls to limit the maximum angle of attack that can be 
attained to a value below that at which an aerodynamic stall would 
occur.

Alpha-Limit

    The maximum angle of attack at which an airplane stabilizes with 
the high incidence protection system operating and the longitudinal 
control held on its aft stop.

VMIN

    The minimum steady flight speed in the airplane's configuration 
under consideration with the high incidence protection system 
operating. See Part I, Section 3, ``Minimum Steady Flight Speed and 
Reference Stall Speed,'' of these special conditions.

VMIN1g

    VMIN corrected to 1g acceleration of gravity conditions. 
See Part I, Section 3, ``Minimum Steady Flight Speed and Reference 
Stall Speed,'' of these special conditions. This is the minimum 
calibrated airspeed at which the airplane can develop a lift force 
normal to the flight path and equal to its weight when at an angle of 
attack not greater than that determined for VMIN.
2. Capability and Reliability of the High Incidence Protection System
    The applicant must establish the capability and reliability of the 
high incidence protection system. The applicant may establish this 
capability and reliability by flight testing, simulation, or analysis 
as appropriate. The capability and reliability required are:
    a. It must not be possible to encounter a stall during the pilot-
induced maneuvers required by Part I, section 5(a), ``High Incidence 
Handling Demonstrations,'' and the handling characteristics must be 
acceptable as required by Part I, section 5(b), ``Characteristics in 
High Incidence Maneuvers'' of these special conditions;
    b. The airplane must be protected against stalling due to the 
effects of wind shears and gusts at low speeds as required by Section 
6, ``Atmospheric Disturbances'' of these special conditions;
    c. The ability of the high incidence protection system to 
accommodate any reduction in stalling incidence must be verified in 
icing conditions;
    d. The high incidence protection system must be provided in each 
abnormal configuration of the high lift devices that is likely to be 
used in flight following system failures; and
    e. The reliability of the system and the effects of failures must 
be acceptable in accordance with Sec.  25.1309.
3. Minimum Steady Flight Speed and Reference Stall Speed
    In lieu of Sec.  25.103, ``Stall speed,'' the following applies:
    a. The minimum steady flight speed, VMIN, is the final, 
stabilized, calibrated airspeed obtained when an airplane is 
decelerated until the longitudinal control is on its stop in such a way 
that the entry rate does not exceed 1 knot per second.
    b. The minimum steady flight speed, VMIN, must be 
determined in icing and non-icing conditions with:
    i. The high incidence protection system operating normally;
    ii. Idle thrust;
    iii. All combinations of flap settings and landing gear positions 
for which VMIN is required to be determined;
    iv. The weight used when the reference stall speed, VSR, 
is used as a factor to determine compliance with a required performance 
standard;
    v. The most unfavorable center of gravity (CG) allowable; and
    vi. The airplane trimmed for straight flight at a speed selected by 
the applicant, but not less than 1.13 VSR and not greater 
than 1.3 VSR.
    c. The 1g minimum steady flight speed, VMIN1g, is the 
minimum calibrated airspeed at which an airplane can develop a lift 
force (normal to the flight path) equal to its weight, while at an 
angle of attack not greater than that at which the minimum steady 
flight speed referenced in section 3(a) of this special condition is 
determined. These minimum calibrated airspeeds must be determined for 
both icing and non-icing conditions.
    d. The reference stall speed, VSR, is a calibrated 
airspeed defined by the applicant. VSR may not be less than 
a 1g stall speed. VSR must be determined in non-icing 
conditions and expressed as:
[GRAPHIC] [TIFF OMITTED] TR16JY18.012

Where:

VCLMAX Demo = Demonstrated calibrated airspeed obtained 
when the corrected lift coefficient of the load factor
[GRAPHIC] [TIFF OMITTED] TR16JY18.013

 is first a maximum during the maneuver
 prescribed in section 3(e)(viii) of this
 special condition.
nZW = Load factor normal to the flight path at 
VCLMAX Demo
W = Airplane gross weight;
S = Aerodynamic reference wing area; and
q = Dynamic pressure.

    e. VCLMAX Demo is determined in non-icing conditions 
with:
    i. Engines idling, or, if that resultant thrust causes an 
appreciable decrease in stall speed, not more than zero thrust at the 
stall speed;
    ii. The airplane in other respects (such as flaps and landing gear) 
in the condition existing in the test or performance standard in which 
VSR is being used;
    iii. The weight used when VSR is being used as a factor 
to determine compliance with a required performance standard;
    iv. The CG position that results in the highest value of the 
reference stall speed;
    v. The airplane trimmed for straight flight at a speed selected by 
the applicant, but not less than 1.13 VSR and not greater 
than 1.3 VSR;
    vi. At the option of the applicant, the high incidence protection 
system can be disabled or adjusted to allow full development of the 
maneuver to the angle of attack corresponding to VSR; and
    vii. Starting from the stabilized trim condition, with an 
application of the longitudinal control to decelerate the airplane so 
that the speed reduction does not exceed 1 knot per second.

[[Page 32762]]

4. Stall Warning
    In lieu of Sec.  25.207, the following apply:
a. Normal Operation
     If the design meets all conditions of Part I, section 2 of these 
special conditions, then the airplane need not provide stall warning 
during normal operation. The conditions of Part I, section 2 provide a 
level of safety equal to the intent of Sec.  25.207, ``Stall warning,'' 
so the provision of an additional, unique warning device for normal 
operations is not required.
b. High Incidence Protection System Failure
     For any failures of the high incidence protection system that the 
applicant cannot show to be extremely improbable, and that result in 
the capability of the system no longer satisfying any part of sections 
2(a), (b), and (c) of Part I of these special conditions: The design 
must provide stall warning that protects against encountering 
unacceptable characteristics and against encountering stall.
    i. This stall warning, with the flaps and landing gear in any 
normal position, must be clear and distinctive to the pilot, and must 
meet the requirements specified in sections 4(b)(iv) and 4(b)(v) of 
Part I of these special conditions.
    ii. The design must also provide this stall warning in each 
abnormal configuration of the high lift devices that is likely to be 
used in flight following system failures.
    iii. The design may furnish this stall warning either through the 
inherent aerodynamic qualities of the airplane or by a device that will 
provide clearly distinguishable indications to the flightcrew under all 
expected conditions of flight. However, a visual stall warning device 
that requires the attention of the flightcrew within the flight deck is 
not acceptable by itself. If a warning device is used, it must provide 
a warning in each of the airplane configurations prescribed in section 
4(b)(i), above, and for the conditions prescribed in sections 4(b)(iv) 
and 4(b)(v) of part I of these special conditions.
    iv. In non-icing conditions, the stall warning must provide 
sufficient margin to prevent encountering unacceptable characteristics 
and encountering stall in the following conditions:
    1. In power-off straight deceleration not exceeding 1 knot per 
second to a speed of 5 knots or 5 percent calibrated airspeed (CAS), 
whichever is greater, below the warning onset; and
    2. In turning flight, stall deceleration at entry rates up to 3 
knots per second when recovery is initiated not less than 1 second 
after the warning onset.
    v. In icing conditions, the stall warning must provide sufficient 
margin to prevent encountering unacceptable characteristics and 
encountering stall in power-off straight and turning flight 
decelerations not exceeding 1 knot per second, when the pilot starts a 
recovery maneuver not less than three seconds after the onset of stall 
warning.
    vi. An airplane is considered stalled when the behavior of the 
airplane gives the pilot a clear, distinctive, and acceptable 
indication that the airplane is stalled. Acceptable indications of a 
stall, occurring either individually or in combination, are:
    1. A nose-down pitch that cannot be readily arrested;
    2. Buffeting of a magnitude and severity that is strong and thereby 
an effective deterrent to further speed reduction; or
    3. The pitch control reaches the aft stop, and no further increase 
in pitch attitude occurs when the control is held full aft for a short 
time before recovery is initiated.
    vii. An airplane exhibits unacceptable characteristics during 
straight or turning flight decelerations if it is not always possible 
to produce and to correct roll and yaw by unreversed use of aileron and 
rudder controls, or abnormal nose-up pitching occurs.
5. Handling Characteristics at High Incidence
a. High Incidence Handling Demonstrations
    In lieu of Sec.  25.201, ``Stall demonstration,'' the following is 
required:
    i. Maneuvers to the limit of the longitudinal control, in the nose-
up sense, must be demonstrated in straight flight and in 30-degree 
banked turns with:
    1. The high incidence protection system operating normally;
    2. Initial power conditions of:
    a. Power off; and
    b. Power necessary to maintain level flight at 1.5 VSR1, 
where VSR1 is the reference stall speed with flaps in 
approach position, landing gear retracted, and maximum landing weight;
    3. None;
    4. Flaps, landing gear, and deceleration devices in any likely 
combination of positions not prohibited by the airplane flight manual 
(AFM);
    5. Representative weights within the range for which certification 
is requested;
    6. The most adverse CG for recovery; and
    7. The airplane trimmed for straight flight at the speed prescribed 
in section 3(e)(v) of these special conditions.
    ii. The following procedures must be used to show compliance in 
non-icing and icing conditions:
    1. Starting at a speed sufficiently above the minimum steady flight 
speed to ensure that a steady rate of speed reduction can be 
established, apply the longitudinal control so that the speed reduction 
does not exceed 1 knot per second until the control reaches the stop.
    2. The longitudinal control must be maintained at the stop until 
the airplane has reached a stabilized flight condition, and must then 
be recovered by normal recovery techniques.
    3. Maneuvers with increased deceleration rates:
    a. In non-icing conditions, the requirements must also be met with 
increased rates of entry to the incidence limit, up to the maximum rate 
achievable.
    b. In icing conditions, with the anti-ice system working normally, 
the requirements must also be met with increased rates of entry to the 
incidence limit, up to three knots per second.
    4. Maneuvers with ice accretion prior to normal operation of the 
ice protection system:
    For flight in icing conditions before the ice protection system has 
been activated and is performing its intended function, the handling 
demonstration requirements identified in section 5(a)(i) must be 
satisfied using the procedures specified in sections 5(a)(ii)(1) and 
5(a)(ii)(2) of these special conditions. The airplane configurations 
required to be tested must be in accordance with the limitations and 
procedures for operating the ice protection system provided in the AFM, 
per Sec.  25.21(g)(1), as modified by and Part II of these special 
conditions.
b. Characteristics in High Incidence Maneuvers
    In lieu of Sec.  25.203, ``Stall characteristics,'' the following 
apply:
    i. Throughout maneuvers with a rate of deceleration of not more 
than 1 knot per second, both in straight flight and in 30-degree banked 
turns, the airplane's characteristics must be as follows:
    1. There must not be any abnormal nose-up pitching;
    2. There must not be any uncommanded nose-down pitching, which 
would be indicative of stall. However, reasonable attitude changes 
associated with stabilizing the incidence at Alpha limit, as the 
longitudinal

[[Page 32763]]

control reaches the stop would be acceptable;
    3. There must not be any uncommanded lateral or directional motion, 
and the pilot must retain good lateral and directional control by 
conventional use of the controls throughout the maneuver; and
    4. The airplane must not exhibit buffeting of a magnitude and 
severity that would act as a deterrent from completing the maneuver 
specified in section 5(a)(i) of these special conditions.
    ii. In maneuvers with increased rates of deceleration, some 
degradation of characteristics is acceptable, associated with a 
transient excursion beyond the stabilized Alpha limit. However, the 
airplane must not exhibit dangerous characteristics or characteristics 
that would deter the pilot from holding the longitudinal control on the 
stop for a period of time appropriate to the maneuver.
    iii. It must always be possible for flightcrew to reduce incidence 
by conventional use of the controls.
    iv. The rate at which the airplane can be maneuvered from trim 
speeds, associated with scheduled operating speeds such as 
V2 and VREF up to Alpha limit, must not be unduly 
damped or be significantly slower than can be achieved on 
conventionally controlled transport airplanes.
c. Characteristics up to the Maximum Lift Angle of Attack
    In addition to the requirements in section 5(b) of this special 
condition, the following requirements apply:
    i. In non-icing conditions, maneuvers with a rate of deceleration 
of not more than 1 knot per second, up to the angle of attack 
corresponding to VSR obtained using sections 3(d) and (e) of 
this special condition, must be demonstrated in straight flight and in 
30-degree banked turns in the following configurations:
    1. The high incidence protection system deactivated or adjusted, at 
the option of the applicant, to allow higher incidence than is possible 
with the normal production system;
    2. Automatic-thrust-increase system inhibited (if applicable);
    3. Engines idling;
    4. Flaps, landing gear, and deceleration devices in any likely 
combination of positions not prohibited by the AFM;
    5. The most adverse CG for recovery; and
    6. The airplane trimmed for straight flight at the speed prescribed 
in section 3(e)(v) of this special condition.
    ii. In icing conditions, maneuvers with a rate of deceleration of 
not more than 1 knot per second up to the maximum angle of attack 
reached during maneuvers from section 5(a)(ii)(3)(b) must be 
demonstrated in straight flight with:
    1. The high incidence protection system deactivated or adjusted, at 
the option of the applicant, to allow higher incidence than is possible 
with the normal production system;
    2. Automatic-thrust-increase system inhibited (if applicable);
    3. Engines idling;
    4. Flaps, landing gear, and deceleration devices in any likely 
combination of positions not prohibited by the AFM;
    5. The most adverse CG for recovery; and
    6. The airplane trimmed for straight flight at the speed prescribed 
in section 3(e)(v) of this special condition.
    iii. During the maneuvers used to show compliance with sections 
5(c)(i) and 5(c)(ii) of Part I of these special conditions, the 
airplane must not exhibit dangerous characteristics and it must always 
be possible for flightcrew to reduce angle of attack by conventional 
use of the controls. The pilot must retain good lateral and directional 
control, by conventional use of the controls, throughout the maneuver.
6. Atmospheric Disturbances
    Operation of the high incidence protection system must not 
adversely affect airplane control during expected levels of atmospheric 
disturbances, nor impede the application of recovery procedures in case 
of wind shear. This must be demonstrated in non-icing and icing 
conditions.
7. None
8. Proof of Compliance
    Add the following requirement to that of Sec.  25.21:
    (b) The flying qualities will be evaluated at the most unfavorable 
CG position.
9. The Design Must Meet the Following Modified Requirements

------------------------------------------------------------------------
           14 CFR section                           Change
------------------------------------------------------------------------
25.145(a)...........................  ``VMIN'' in lieu of ``stall
                                       identification.''
25.145(b)(6)........................  ``VMIN'' in lieu of ``VSW.''
25.175(c) and (d)...................  ``VMIN'' in lieu of ``VSW.''
25.1323(d)..........................  ``From 1.23 VSR to VMIN'' in lieu
                                       of ``From 1.23 VSR to the speed
                                       at which stall warning begins;''
                                       and ``speeds below VMIN'' in lieu
                                       of ``speeds below stall warning
                                       speed.''
------------------------------------------------------------------------

Part II: Credit for Robust Envelope Protection in Icing Conditions

    1. In lieu of Sec.  25.21(g)(1), the following applies:
    (g) The requirements of this subpart associated with icing 
conditions apply only if certification for flight in icing conditions 
is desired. If certification for flight in icing conditions is desired, 
the following requirements also apply (see AC 25-25):
    (1) Each requirement of this subpart, except Sec. Sec.  25.121(a), 
25.123(c), 25.143(b)(1) and (b)(2), 25.149, 25.201(c)(2), 25.207(c) and 
(d), and 25.251(b) through (e), must be met in icing conditions. 
Compliance must be shown using the ice accretions defined in appendix C 
to part 25, assuming normal operation of the airplane and its ice 
protection system in accordance with the operating limitations and 
operating procedures established by the applicant and provided in the 
airplane flight manual.
    2. In lieu of Sec.  25.103, ``Stall speed,'' define the stall speed 
as provided in Special Conditions Part I, section 3, ``Minimum Steady 
Flight Speed and Reference Stall Speed.''
    3. In lieu of Sec.  25.105(a)(2)(i) to read as follows:
    (2) In icing conditions, if in the configuration of Sec.  25.121(b) 
with the ``Takeoff Ice'' accretion defined in appendix C to part 25:
    (i) The V2 speed scheduled in non-icing conditions does not provide 
the maneuvering capability specified in Sec.  25.143(h) for the takeoff 
configuration, or
    4. In lieu of Sec.  25.107(c) and (g), the following apply, with 
additional sections (c') and (g'):
    (c) In non-icing conditions, V2, in terms of calibrated 
airspeed, must be selected by the applicant to provide at least the 
gradient of climb required by Sec.  25.121(b) but may not be less 
than--
    1. V2MIN;
    2. VR plus the speed increment attained (in accordance 
with Sec.  25.111(c)(2)) before reaching a height of 35 feet above the 
takeoff surface; and
    3. A speed that provides the maneuvering capability specified in 
Sec.  25.143(h).
    (c') In icing conditions with the ``Takeoff Ice'' accretion defined 
in appendix C to part 25, V2 may not be less than--
    1. The V2 speed determined in non-icing conditions.
    2. A speed that provides the maneuvering capability specified in 
Sec.  25.143(h).
    (g) In non-icing conditions, VFTO, in terms of 
calibrated airspeed, must be

[[Page 32764]]

selected by the applicant to provide at least the gradient of climb 
required by Sec.  25.121(c), but may not be less than--
    1. 1.18 VSR; and
    2. A speed that provides the maneuvering capability specified in 
Sec.  25.143(h).
    (g') In icing conditions with the ``Final Takeoff Ice'' accretion 
defined in appendix C to part 25, VFTO may not be less 
than--
    1. The VFTO speed determined in non-icing conditions.
    2. A speed that provides the maneuvering capability specified in 
Sec.  25.143(h).
    5. In lieu of Sec. Sec.  25.121(b)(2)(ii)(A), 25.121(c)(2)(ii)(A), 
and 25.121(d)(2)(ii), the following apply:
    Sec.  25.121 Climb: one-engine inoperative:
    (b) Takeoff; landing gear retracted. In the takeoff configuration 
existing at the point of the flight path at which the landing gear is 
fully retracted, and in the configuration used in Sec.  25.111, but 
without ground effect,
* * * * *
    2. The requirements of subparagraph (b)(1) of this section must be 
met:
* * * * *
    (ii) In icing conditions with the ``Takeoff Ice'' accretion defined 
in appendix C of part 25, if in the configuration of Sec.  25.121(b) 
with the ``Takeoff Ice'' accretion:
    (A) The V2 speed scheduled in non-icing conditions does 
not provide the maneuvering capability specified in Sec.  25.143(h) for 
the takeoff configuration; or
    (c) Final takeoff. In the en route configuration at the end of the 
takeoff path determined in accordance with Sec.  25.111:
* * * * *
    2. The requirements of subparagraph (c)(1) of this section must be 
met:
* * * * *
    (ii) In icing conditions with the ``Final Takeoff Ice'' accretion 
defined in appendix C of part 25, if:
    (A) The VFTO speed scheduled in non-icing conditions 
does not provide the maneuvering capability specified in Sec.  
25.143(h) for the en route configuration; or
    (d) Approach. In a configuration corresponding to the normal all-
engines operating procedure in which VSR for this 
configuration does not exceed 110 percent of the VSR for the 
related all-engines-operating landing configuration:
* * * * *
    2. The requirements of sub-paragraph (d)(1) of this section must be 
met:
* * * * *
    (ii) In icing conditions with the ``Approach Ice'' accretion 
defined in appendix C to part 25, in a configuration corresponding to 
the normal all-engines-operating procedure in which VMIN1g 
for this configuration does not exceed 110% of the VMIN1g 
for the related all engines-operating landing configuration in icing, 
with a climb speed established with normal landing procedures, but not 
more than 1.4 VSR (VSR determined in non-icing 
conditions).
    6. In lieu of Sec.  25.123 (b)(2)(i), the following applies:
    Sec.  25.123 En route flight paths:
    (b) The one-engine-inoperative net flight path data must represent 
the actual climb performance diminished by a gradient of climb of 1.1 
percent for two-engine airplanes, 1.4 percent for three-engine 
airplanes, and 1.6 percent for four-engine airplanes.
* * * * *
    2. In icing conditions with the ``En route Ice'' accretion defined 
in appendix C to part 25 if:
    (i) The minimum en route speed scheduled in non-icing conditions 
does not provide the maneuvering capability specified in Sec.  
25.143(h) for the en route configuration, or
    7. In lieu of Sec.  25.125(b)(2)(ii)(B) and Sec.  
25.125(b)(2)(ii)(C), the following applies:
    Sec.  25.125 Landing
    (b) In determining the distance in (a):
* * * * *
    2. A stabilized approach, with a calibrated airspeed of not less 
than VREF, must be maintained down to the 50-foot height.
* * * * *
    (ii) In icing conditions, VREF may not be less than:
    (A) The speed determined in sub-paragraph (b)(2)(i) of this 
section;
    (B) A speed that provides the maneuvering capability specified in 
Sec.  25.143(h) with the ``Landing Ice'' accretion defined in appendix 
C to part 25.
    8. In lieu of Sec.  25.143(j), the following applies:
    Sec.  25.143 General
    (j) For flight in icing conditions--before the ice protection 
system has been activated and is performing its intended function--the 
following requirements apply:
    (1) If activating the ice protection system depends on the pilot 
seeing a specified ice accretion on a reference surface (not just the 
first indication of icing), the requirements of Sec.  25.143 apply with 
the ice accretion defined in part II(e) of appendix C to part 25.
    (2) For other means of activating the ice protection system, it 
must be demonstrated in flight with the ice accretion defined in part 
II(e) of appendix C to part 25 that:
    (i) The airplane is controllable in a pull-up maneuver up to 1.5 g 
load factor or lower if limited by AOA protection; and
    (ii) There is no reversal of pitch control force during a pushover 
maneuver down to 0.5 g load factor.
    9. In lieu of Sec.  25.207, ``Stall warning,'' to read as the 
requirements defined in Part I of these special conditions.

    Issued in Des Moines, Washington, on July 9, 2018.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division, 
Aircraft Certification Service.
[FR Doc. 2018-15071 Filed 7-13-18; 8:45 am]
 BILLING CODE 4910-13-P

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