[Federal Register Volume 78, Number 33 (Tuesday, February 19, 2013)]
[Rules and Regulations]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-03658]
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.
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.
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
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.
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
load condition at design maneuvering speed (VA), in which
the cockpit roll control is returned to neutral following the initial
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.
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.
This action affects only certain novel or unusual design features
on one model EMB-550 of airplanes. It is not a rule of general
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
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
(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.
Manager, Transport Airplane Directorate, Aircraft Certification
[FR Doc. 2013-03658 Filed 2-15-13; 8:45 am]
BILLING CODE 4910-13-P