[Federal Register: January 30, 1998 (Volume 63, Number 20)] [Rules and Regulations] [Page 4563-4564] From the Federal Register Online via GPO Access [wais.access.gpo.gov] [DOCID:fr30ja98-4] [[Page 4563]] ======================================================================= ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 23 [Docket No. 143CE; Special Conditions No. SC-23-ACE-93] Special Conditions: EXTRA Flugzeugbau GmbH, Model EA-400; Heat Capability of the Engine Mount and the Fuselage Connection Joint AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions. ----------------------------------------------------------------------- SUMMARY: These special conditions are issued for the EXTRA Flugzeugbau GmbH, Model EA-400 airplane. This airplane will have a novel or unusual design feature associated with the Heat Capability of the Engine Mount and the Fuselage Connection Joint. 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. EFFECTIVE DATE: March 2, 1998. FOR FURTHER INFORMATION CONTACT: Kenneth W. Payauys, Aerospace Engineer, Standards Office (ACE-110), Small Airplane Directorate, Aircraft Certification Service, Federal Aviation Administration, 601 East 12th Street, Kansas City, Missouri 64106; telephone (816) 426-5688. SUPPLEMENTARY INFORMATION: Background On April 6, 1993, EXTRA Flugzeugbau GmbH applied for a type certificate for their new Model EA-400. The EA-400 design is a two- place (side-by-side), all composite material, cantilevered high-wing, retractable gear, unpressurized, single reciprocating engine airplane with a maximum design weight of 3,974 pounds (1800 kilograms). It is intended for 14 CFR part 91 operation as a day-VFR normal category airplane. The proposed type design of the EXTRA Flugzeugbau GmbH Model EA-400 airplane incorporates certain novel and unusual design features for which the exiting airworthiness regulations do not contain adequate or appropriate safety standards. These features include certain performance characteristics necessary for this type of airplane design that were not foreseen by the existing regulations. This special condition addresses the flight safety of the EA-400 in case of an engine compartment fire with resulting heat conduction through the engine-mounts to composite structure joints beyond the firewall. The type certificate applicant shall demonstrate that the airplane structure design, especially the engine-mount attachments to the structure beyond the firewall, is able to retain the engine while withstanding the following: 1. An engine compartment fire, the loss of the most highly loaded composite joint, and heating of the next most highly loaded composite joint from those that remain; 2. Maximum continuous power for 5 minutes; and 3. Combined airplane flight maneuver and gust limit loads for at least 15 minutes. Note: The engine-mount attachments at the firewall are not the same as the engine-to-engine-mount attachments, which contain vibration dampers. Type Certification Basis Under the provisions of 14 CFR part 21, Sec. 21.17, EXTRA Flugzeugbau GmbH must show that the Model EA-400 meets the applicable provisions of 14 CFR part 23, effective February 1, 1965, through amendment 23-45, effective August 6, 1993; 14 CFR part 36, effective December 1, 1969, through amendment 36-21 effective December 28, 1995; exemptions, if any; equivalent level of safety findings, if any; and the special conditions adopted by this rulemaking action. Special conditions are issued, as appropriate, under 14 CFR part 11 Sec. 11.49 after public notice, as required by Sec. 11.28 and Sec. 11.29(b), and become part of the type certification basis in accordance with 14 CFR part 21, Sec. 21.17(a)(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 the same novel or unusual design feature, the special conditions would also apply to the other model under the provisions of 14 CFR part 21, Sec. 21.101(a)(1)). Novel or Unusual Design Features The Model EA-400 will incorporate the following novel or unusual design features: Heat Capability of the Engine Mount and the Fuselage Connection Joint. Discussion of Comments Notice of proposed special conditions No. SC-23-ACE-93 for the EXTRA Flugzeugbau GmbH EA-400 airplanes was published on November 20, 1997 (62 FR 61926). No comments were received and the special conditions are adopted as proposed. Applicability As discussed above, these special conditions are applicable to the Model A-400. Should EXTRA Flugzeugbau GmbH apply at a later date for a change to the type certificate to include another model incorporating the same level or unusual design feature, the 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 23 Aircraft, Aviation safety, Signs and symbols. Citation The authority citation for these special conditions is as follows: Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and 21.17; and 14 CFR 11.28 and 11.49. 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 EXTRA Flugzeugbau GmbH Model EA-400 airplanes: Heat Capability of the Engine Mount and the Fuselage Connection Joint (a) Modify the airworthiness standards given in 14 CFR part 23, POWERPLANT FIRE PROTECTION, Nacelle areas behind firewalls (Sec. 23.1182), by making the most critical composite engine-mount attachment ineffective (assumed destroyed by heat). Then, for 15 minutes, apply an additional flame test of 500 deg. C (932 deg. F) to the next most structurally critical engine-mount of those remaining. The flame shall encompass the whole engine-mount structural attach fitting. Conductive heat will affect the metallic and composite joint structural capability beyond the firewall. Test the joint structural capability with these simultaneous limit load conditions (under these conditions, the engine shall remain attached to the airplane): [[Page 4564]] (1) The combined thrust, torque and gyroscopic loads resulting from the engine and propeller at maximum continuous power for the first 5 minutes, and (2) The airplane normal inertial limit loads that result from the following: (i) A maneuver load factor equal to that obtained from a constant altitude 30 deg. bank, combined with (ii) The positive and negative vertical design gust load factors that occur at the design maneuvering speed and the minimum flying weight, and (iii) A factor-of-safety equal to one. Issued in Kansas City, Missouri on January 22, 1998. Marvin Nuss, Assistant Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-2399 Filed 1-29-98; 8:45 am] BILLING CODE 4910-13-M