Document ID: FAA-2012-1211-0004
Agency: faa
Document Type: Rule
Title: Special Conditions: Embraer S.A., ModelEMB-550 Airplanes; Flight Envelope Protection: Pitch and Roll Limiting Functions
Posted Date: 2013-03-04T05:00Z

[Federal Register Volume 78, Number 42 (Monday, March 4, 2013)]
[Rules and Regulations]
[Pages 14005-14007]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-04855]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2012-1211; Special Conditions No. 25-486-SC]

Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight 
Envelope Protection: Pitch and Roll Limiting Functions

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 associated with pitch and roll limiting functions, specifically 
an electronic flight control system which contains fly-by-wire control 
laws, including envelope protections. 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: April 3, 2013.

FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, FAA, Airplane and Flight 
Crew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; telephone 425-227-2011; 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 a 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

[[Page 14006]]

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, aileron and rudder, controlled by the 
pilot or copilot sidestick.
    The airworthiness standards in Title 14, Code of Federal 
Regulations (14 CFR) part 25 do not specifically relate to flight 
characteristics associated with fixed attitude limits. Embraer S.A. 
will implement pitch and roll attitude protection functions through the 
normal modes of the electronic flight control system that will provide 
speed stability for high and low pitch angles. These functions also 
provide strong spiral stability for roll angles at high bank angles. In 
addition, bank angle limiting is introduced at speeds greater than 
VMO/MMO, up to VDF/MDF.

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-550 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 Model EMB-550 airplane will incorporate the following novel or 
unusual design feature: An electronic flight control system which 
contains fly-by-wire control laws, including envelope protections, 
which were not envisioned when part 25 was written.

Discussion

    We expect that high thrust-to-weight ratios will provide the most 
critical cases for the positive pitch limit. A margin in pitch control 
must be available to enable speed control in maneuvers such as climb 
after takeoff and balked landing climb. The pitch limit must not impede 
likely maneuvering made necessary by collision avoidance efforts. A 
negative pitch limit must similarly not interfere with collision 
avoidance capability or with attaining and maintaining speeds near 
VMO/MMO for emergency descent.
    Spiral stability must not restrict attaining roll angles up to 65 
degrees (i.e., an approximately 2.4g-level turn). This force must not 
require excessive pilot strength as stated in Sec.  25.143(f).
    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. 25-12-10-SC for the 
Embraer S.A. Model EMB-550 airplanes was published in the Federal 
Register on November 20, 2012 (77 FR 69569). We received one comment 
from Mr. Sokolow, who stated that these types of rules should be 
generic and not pertain to one model. He said that it splinters the 
regulations and can lead to abuse.
    We acknowledge Mr. Sokolow's concerns about issuing regulations for 
individual models. In the case of new technlogy or new designs that are 
not covered in the regulations, the FAA issues special conditions that 
are applicable to only one model of airplane. The Embraer S.A. Model 
EMB-550 airplane will have a novel or unusual design feature associated 
with pitch and roll limiting functions, specifically an electronic 
flight control system which contains fly-by-wire control laws, 
including envelope protections. 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.
    We agree with the commenter that the FAA should issue general 
rulemaking to cover general issues that affect many types of airplanes. 
Currently, the FAA is tasking an Aviation Rulemaking Advisory Committee 
(ARAC) to address this and other similar requirements for electronic 
flight control systems (EFCS). The goal is to develop general rules 
that could be applied to all designs. In the meantime, however, we will 
continue to issue special conditions to ensure an adequate level of 
safety for specific EFCS design features.
    We are adopting the special conditions 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 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

0
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.
    In addition to Sec.  25.143, the following requirements apply:
    1. Flight Envelope Protection: Pitch and Roll Limiting Functions.
    a. The pitch limiting function must not impede normal maneuvering 
for pitch angles up to the maximum required for normal maneuvering, 
including a normal all-engines operating takeoff, plus a suitable 
margin to allow for satisfactory speed control.
    b. The pitch and roll limiting functions must not restrict or 
prevent attaining pitch attitudes necessary for emergency maneuvering 
or roll angles up to 66 degrees with flaps up, or 60 degrees with flaps 
down. Spiral

[[Page 14007]]

stability, which is introduced above 33 degrees roll angle, must not 
require excessive pilot strength to achieve these roll angles. Other 
protections, which further limit the roll capability under certain 
extreme angle of attack or attitude or high speed conditions, are 
acceptable, as long as they allow at least 45 degrees of roll 
capability.
    c. A lower limit of roll is acceptable beyond the overspeed warning 
if it is possible to recover the aircraft to the normal flight envelope 
without undue difficulty or delay.

    Issued in Renton, Washington, on February 26, 2013.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-04855 Filed 3-1-13; 8:45 am]
BILLING CODE 4910-13-P