07-1809. Special Conditions: Dassault Aviation, Model Falcon 7X; Design Roll Maneuvering Conditions

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final special conditions; request for comments.

SUMMARY:

These special conditions are issued for the Dassault Aviation Falcon 7X airplane. This airplane will have a novel or unusual design feature associated with an electronic fly-by-wire flight control system. 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:

The effective date of these special conditions is April 4, 2007. We must receive your comments by May 16, 2007.

ADDRESSES:

You must mail two copies of your comments to: Federal Aviation Administration, Transport Airplane Directorate, Attn: Rules Docket (ANM-113), Docket No. NM374, 1601 Lind Avenue, SW., Renton, Washington, 98057-3356. You may deliver two copies to the Transport Airplane Directorate at the above address. You must mark your comments: Docket No. NM374. You can inspect comments in the Rules Docket weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT:

Rich Yarges, FAA, Airframe/Cabin Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; facsimile [phone].

SUPPLEMENTARY INFORMATION:

The FAA has determined that notice and opportunity for prior public comment hereon are impracticable because these procedures would significantly delay issuance of the approval design and thus delivery of the affected aircraft. 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 therefore finds that good cause exists for making these special conditions effective upon issuance.

Comments Invited

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 ask that you send us two copies of written comments.

We will file in the docket all comments we receive as well as a report summarizing each substantive public contact with FAA personnel about these special conditions. You can inspect the docket before and after the comment closing date. If you wish to review the docket in person, go to the address in the ADDRESSES section of this preamble between 7:30 a.m. and 4 p.m., Monday through Friday, except Federal holidays.

We will consider all comments we receive by the closing date for comments. We will consider comments filed late if it is possible to do so without incurring expense or delay. We may change these special conditions based on the comments we receive.

If you want us to let you know we received your comments on these special conditions, send us a pre-addressed, stamped postcard on which the docket number appears. We will stamp the date on the postcard and mail it back to you.

Background

On June 4, 2002, Dassault Aviation, 9 rond Point des Champs Elysees, 75008, Paris, France, applied for a type certificate for its new Model Falcon 7X. The Dassault Aviation Falcon 7X is a 19 passenger transport category airplane, powered by three aft mounted Pratt & Whitney PW307A high bypass ratio turbofan engines. The airplane is operated using a fly-by-wire electronic flight control system. This flight control system does not provide a mechanical link between the airplane flight control surface and the pilot's cockpit control device as there is on more conventional airplanes. This will be the first application of such a system in an airplane primarily intended for private or corporate use. However, several models of airplanes certificated under part 25 have incorporated fly-by-wire electronic flight control systems.

Type Certification Basis

Under the provisions of 14 CFR 21.17, Dassault Aviation must show that the Model Falcon 7X meets the applicable provisions of Part 14 CFR part 25, as amended by Amendment 25-1 through 25-107.

If the Administrator finds that the applicable airworthiness regulations do not contain adequate or appropriate safety standards for the Model Falcon 7X because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16.

In addition to the applicable airworthiness regulations and special conditions, the Dassault Model Falcon 7X 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, and the FAA must issue a finding of regulatory adequacy under § 611 of Public Law 92-574, the “Noise Control Act of 1972.”

The FAA issues special conditions, as defined in § 11.19, under § 11.38, and they become part of the type certification basis under § 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.

Novel or Unusual Design Features

The Falcon 7X is equipped with an electronic flight control system. In this system, there is not a direct mechanical link between the airplane flight control surface and the pilot's cockpit control device as there is on more conventional airplanes. Instead, a flight control computer commands the airplane flight control surfaces, based on input received from the cockpit control device. The pilot input is modified by the flight control computer—based on the current airplane flight parameters—before the command is given to the flight control surface.

Discussion

The formulation of airplane design load conditions in 14 CFR part 25 is based on the assumption that the airplane is equipped with a control system in which there is a direct mechanical linkage between the pilot's cockpit control and the control surface. Thus, for roll maneuvers, the regulation specifies a displacement for the aileron itself and does not envision any modification of the pilot's control input. Since such a system will affect the airplane flight loads and thus the structural strength of the airplane, special conditions appropriate for this type of control system are needed.

In particular, the special condition adjusts the design roll maneuver requirements specified in § 25.349(a), so that they take into account the effect of the Falcon 7X's electronic flight control computer on the control surface deflection. The special condition requires that the roll maneuver be performed by deflection of the cockpit roll control, as opposed to specifying a deflection of the aileron itself as the current regulation does. The deflection of the control surface would then be determined from the cockpit input, based on the computer's flight control laws and the current airplane flight parameters.

Applicability

As discussed above, these special conditions are applicable to the Dassault Aviation Model Falcon 7X. Should Dassault Aviation apply at a later date for a change to the type certificate to include another model incorporating the same novel or unusual design feature, the special conditions would apply to that model as well.

Conclusion

This action affects only certain novel or unusual design features of the Dassault Aviation Model Falcon 7X of airplane. It is not a rule of general applicability.

The substance of these special conditions has been subjected to the notice and comment period in several prior instances and has been derived without substantive change from those previously issued. It is unlikely that public comment would result in a significant change from the substance contained herein. Therefore, because a delay would significantly affect the certification of the airplane, which is imminent, the FAA has determined that prior public notice and comment are unnecessary and impracticable and that good cause exists for adopting these special conditions upon issuance. 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.

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 Dassault Aviation Model Falcon 7X airplanes.

Design Roll Maneuvering Conditions

In lieu of compliance with 14 CFR 25.349(a), the following special conditions apply:

Maneuvering: 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 the two-thirds of limit positive maneuvering load factor. In determining the resulting control surface deflections, the torsional flexibility of the wing must be considered in accordance with 14 CFR 25.301(b):

(1) Conditions corresponding to maximum steady rolling velocities and conditions corresponding to maximum angular accelerations must be investigated. For the angular acceleration conditions, zero rolling velocity may be assumed in the absence of a rational time history investigation of the maneuver.

(2) At V_A, 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.

(3) 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 sub-paragraph (2) of this paragraph.

(4) 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 sub-paragraph (2) of this paragraph.

Issued in Renton, Washington, on April 4, 2007.

Stephen P. Boyd,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.