Rules and Regulations. Final special conditions; request for comments

Agency: Federal Aviation Administration (FAA), DOT
Action: Final special conditions; request for comments
Citation: FR Doc. 2017-16417 · Docket No. FAA-2017-0732; Special Conditions No. 25-697-SC · 14 CFR 25

Summary

These special conditions are issued for the Embraer S.A. (Embraer) Model ERJ 190-300 series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is an electronic flight control system (EFCS) that provides control of the airplane through pilot inputs to the flight computer. 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 of safety equivalent to that established by the existing airworthiness standards.

Dates

This action is effective on Embraer on August 4, 2017. We must receive your comments by September 18, 2017.

Supplementary Information

The FAA has determined that notice of, and opportunity for prior public comment on, these special conditions is impracticable because these procedures would delay issuance of the design approval and thus delivery of the affected airplane. In addition, the substance of these special conditions has been subject to the public comment process in several prior instances with no substantive comments received. The FAA finds it is unnecessary to delay the effective date and finds that good cause exists for adopting these special conditions upon publication in the Federal Register . Comments Invited The FAA is requesting comments to allow interested persons to submit views that may not have been submitted in response to the prior opportunities for comment described above. We invite interested people to take part in this rulemaking by sending written comments, data, or views. The most helpful comments reference a specific portion of the special conditions, explain the reason for any recommended change, and include supporting data. We will consider all comments we receive by the closing date for comments. We may change these special conditions based on the comments we receive. Background On September 13, 2013, Embraer applied for an amendment to Type Certificate (TC) no. A57NM to include the new Model ERJ 190-300 airplanes. The Model ERJ 190-300 airplane, which is a derivative of the Model ERJ 190-100 STD airplane currently approved under TC no. A57NM, is a 97-114 passenger transport-category airplane with two Pratt & Whitney Model PW1900G engines, a new wing design with a high aspect ratio and raked wingtip, and a digital fly-by-wire electronic flight-control system. The flight-control system for the Model ERJ 190-300 airplane does not have a direct mechanical link nor a linear gain between the airplane flight-control surface and the pilot's flight-deck control device, which is not accounted for in title 14, Code of Federal Regulations (14 CFR) 25.349(a). Instead, a flight-control computer commands the airplane flight-control surfaces, based on input received from the flight-deck control device. The flight-control computer modifies pilot input before the command is given to the flight-control surface. Type Certification Basis Under the provisions of 14 CFR 21.101, Embraer must show that the Model ERJ 190-300 airplane meets the applicable provisions of the regulations listed in Type Certificate No. A57NM or the applicable regulations in effect on the date of application for the change, except for earlier amendments as agreed upon by the FAA. 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 Model ERJ 190-300 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 features, or should any other model already included on the same type certificate be modified to incorporate 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 ERJ 190-300 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 § 11.38, and they become part of the type certification basis under § 21.101. Novel or Unusual Design Features The ERJ 190-300 will incorporate the following novel or unusual design features: An electronic flight control system that provides control of the airplane through pilot inputs to the flight computer. Current part 25 airworthiness regulations account for control laws where aileron deflection is proportional to control stick deflection. They do not address any nonlinearities, i.e., situations where output does not change in the same proportion as input, or other effects on aileron actuation that may be caused by electronic flight controls. Discussion These special conditions differ from current regulatory requirements in that they require that the roll maneuver result from defined movements of the cockpit roll control as opposed to defined aileron deflections. Also, these special conditions require an additional load condition at design maneuvering speed (V ^A ), in which the cockpit roll control is returned to neutral following the initial roll input. These special conditions differ from similar special conditions previously issued on this topic. These special conditions are limited to the roll axis only, whereas other special conditions also included pitch and yaw axes. Special conditions are no longer needed for the yaw axis because 14 CFR 25.351 was revised at Amendment 25-91 to take into account effects of an electronic flight control system. No special conditions are needed for the pitch axis because the method that Embraer proposed for the pitch maneuver takes into account effects of an electronic flight control system. These special conditions 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. Applicability As discussed above, these special conditions are applicable to the Model ERJ 190-300 airplanes. Should Embraer 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. Conclusion This action affects only certain novel or unusual design features on one model 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. The authority citation for these special conditions is as follows: Authority: 49 U.S.C. 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 the Embraer Model ERJ 190-300 series airplanes. In lieu of compliance to 14 CFR 25.349(a), the Embraer Model ERJ 190-300 airplane must comply with the following: The following conditions, speeds, and cockpit roll control motions (except as the motions may be limited by pilot effort) must be considered in combination with an airplane load factor of zero and of two-thirds of the positive maneuvering factor used in design. In determining the resulting control surface deflections, the torsional flexibility of the wing must be considered in accordance with 14 CFR 25.301(b). (a) Conditions corresponding to steady rolling velocities must be investigated. In addition, conditions corresponding to maximum angular acceleration must be investigated for airplanes with engines or other weight concentrations outboard of the fuselage. For the angular acceleration conditions, zero rolling velocity may be assumed in the absence of a rational time history investigation of the maneuver. (b) At V ^A , sudden movement of the cockpit roll control up to the limit is assumed. The position of the cockpit roll control must be maintained until a steady roll rate is achieved and then must be returned suddenly to the neutral position. (c) At V ^C , the cockpit roll control must be moved suddenly and maintained so as to achieve a roll rate not less than that obtained in paragraph (b). (d) At V ^D , the cockpit roll control must be moved suddenly and maintained so as to achieve a roll rate not less than one third of that obtained in paragraph (b). Issued in Renton, Washington. Victor Wicklund, Manager, Transport Standards Branch, Aircraft Certification Service. [FR Doc. 2017-16417 Filed 8-3-17; 8:45 am]