Document ID: FAA-2012-1241-0002
Agency: faa
Document Type: Rule
Title: Special Conditions: Embraer S.A., Model EMB-550 Airplane; Design Roll Maneuver for Electronic Flight Controls
Posted Date: 2013-02-19T05:00Z

[Federal Register Volume 78, Number 33 (Tuesday, February 19, 2013)]
[Rules and Regulations]
[Pages 11555-11556]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-03658]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2012-1241; Special Conditions No. 25-480-SC]

Special Conditions: Embraer S.A., Model EMB-550 Airplane; Design 
Roll Maneuver for Electronic Flight Controls

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

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SUMMARY: These special conditions are issued for the Embraer S.A. Model 
EMB-550 airplane. This airplane will have a novel or unusual design 
feature(s) associated with the design roll maneuver for electronic 
flight controls, specifically an electronic flight control system that 
provides control of the aircraft 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: Effective Date: March 21, 2013.

FOR FURTHER INFORMATION CONTACT: Todd Martin, FAA, Airframe and Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington, 98057-
3356; telephone 425-227-1178; facsimile 425-227-1149.

SUPPLEMENTARY INFORMATION:

Background

    On May 14, 2009, Embraer S.A. applied for a type certificate for 
their new Model EMB-550 airplane. The Model EMB-550 airplane is the 
first of a new family of jet airplanes designed for corporate flight, 
fractional, charter, and private owner operations. The aircraft has a 
conventional configuration with low wing and T-tail empennage. The 
primary structure is metal with composite empennage and control 
surfaces. The Model EMB-550 airplane is designed for 8 passengers, with 
a maximum of 12 passengers. It is equipped with two Honeywell HTF7500-E 
medium bypass ratio turbofan engines mounted on aft fuselage pylons. 
Each engine produces approximately 6,540 pounds of thrust for normal 
takeoff. The primary flight controls consist of hydraulically powered 
fly-by-wire elevators, ailerons, and rudder, controlled by the pilot or 
copilot sidestick.
    The flight control system for the Model EMB-550 airplane does not 
have a direct mechanical link or a linear gain between the airplane 
flight control surface and the pilot's cockpit 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 cockpit 
control device. The pilot input is modified by the flight control 
computer before the command is given to the flight control surface.

Type Certification Basis

    Under the provisions of 14 CFR 21.17, Embraer S.A. must show that 
the Model EMB-550 airplane meets the applicable provisions of part 25, 
as amended by Amendments 25-1 through 25-127 thereto.
    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 EMB-500 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 or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model EMB-550 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 and the FAA must issue a 
finding of regulatory adequacy under section 611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''
    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 Embraer S.A. Model EMB-550 airplane will incorporate the 
following novel or unusual design features: The Model EMB-550 airplane 
is equipped with an electronic flight control system that provides 
control of the aircraft 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

[[Page 11556]]

load condition at design maneuvering speed (VA), 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 S.A. 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.

Discussion of Comments

    Notice of proposed special conditions No. 25-12-15-SC for the 
Embraer S.A. EMB-550 airplanes was published in the Federal Register on 
November 26, 2012 (77 FR 70384). No comments were received, and the 
special conditions are adopted as proposed.

Applicability

    As discussed above, these special conditions are applicable to the 
Model EMB-550 airplane. Should Embraer S.A. 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 
on one model EMB-550 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.

0
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 Embraer S.A. Model EMB-550 airplanes.
    1. Design Roll Maneuver for Electronic Flight Controls.
    In lieu of compliance to 14 CFR 25.349(a), the Embraer S.A. Model 
EMB-550 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 VA, 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 VC, 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 VD, 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, on February 12, 2013.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-03658 Filed 2-15-13; 8:45 am]
BILLING CODE 4910-13-P