[Federal Register Volume 78, Number 26 (Thursday, February 7, 2013)]
[Rules and Regulations]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-02740]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2012-1200; Special Conditions No. 25-475-SC]
Special Conditions: Embraer S.A., Model EMB-550 Airplane;
Hydrophobic Coatings in Lieu of Windshield Wipers
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 hydrophobic coatings. 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 11, 2013.
FOR FURTHER INFORMATION CONTACT: Paul Bernado, FAA, Airplane and Flight
Crew Interface Branch, ANM-111, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue SW., Renton,
Washington, 98057-3356; telephone 425-227-1209; facsimile 425-227-1320.
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, aileron and rudder, controlled by the pilot or
The Model EMB-550 airplane will use a hydrophobic coating on the
windshield in lieu of windshield wipers. The existing regulation, Title
14, Code of Federal Regulations (14 CFR) 25.773(b)(1), requires a means
to maintain a sufficiently clear portion of the windshield for both
pilots to have sufficiently extensive view along the flight path during
precipitation conditions in heavy rain at speeds up to 1.5
VSR1. The heavy rain and high speed conditions in the rule
do not necessarily represent the limiting condition for this new
technology. For example, airflow over the windshield may be necessary
to remove moisture, but may not be adequate to maintain a sufficiently
clear area of the windshield in low speed flight or during surface
operations. Alternatively, airflow over the windshield may be disturbed
during critical times such as the approach to land, where the airplane
is at higher-than-normal pitch angle.
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 Embraer S.A. 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 Sec. 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
has a hydrophobic coating on the windshield to provide adequate pilot
compartment view in precipitation in lieu of windshield wipers.
14 CFR 25.773(b)(1) requires a means to maintain a clear portion of
the windshield for both pilots to have a sufficiently extensive view
along the flight path during precipitation conditions. The regulations
require this means to maintain such an area during precipitation in
heavy rain at speeds up to 1.5 VSR1. The requirement that
the means to maintain a clear area of forward vision must function at
high speeds and high precipitation rates is based on the use of
windshield wipers as the means to maintain an adequate area of clear
vision in precipitation conditions. The requirement in 14 CFR
121.313(b), and in 14 CFR 125.213(b), to provide ``a windshield wiper
or equivalent for each pilot station'' has remained unchanged since at
The effectiveness of windshield wipers to maintain an area of clear
vision normally degrades as airspeed and precipitation rates increase.
It is assumed that because high speeds and high precipitation rates
represent limiting conditions for windshield wipers, they will also be
effective at lower speeds and precipitation levels. Accordingly, Sec.
25.773(b)(1)(i) does not require maintenance of a clear area of forward
vision at lower speeds or lower precipitation rates.
A forced airflow blown directly over the windshield has also been
used to maintain an area of clear vision in precipitation. The limiting
for this technology are comparable to those for windshield wipers.
Accordingly, introduction of this technology did not present a need for
special conditions to maintain the level of safety embodied in the
Hydrophobic windshield coatings may depend to some degree on
airflow directly over the windshield to maintain a clear vision area.
The heavy rain and high-speed conditions specified in the current rule
do not necessarily represent the limiting conditions for this new
technology. For example, airflow over the windshield, which may be
necessary to remove moisture from the windshield, may not be adequate
to maintain a sufficiently clear area of the windshield in low speed
flight or during ground operations. Alternatively, airflow over the
windshield may be disturbed during such critical times as the approach
to land, where the airplane is at a higher than normal pitch attitude.
In these cases, areas of airflow disturbance or separation on the
windshield could cause failure to maintain a clear vision area on the
In addition to potentially depending on airflow to function
effectively, hydrophobic coatings may also be dependent on water
droplet size for effective precipitation removal. For example,
precipitation in the form of a light mist may not be sufficient for the
coating's properties to result in maintaining a clear area of vision.
In summary, the current regulations identify speed and
precipitation rate requirements that represent limiting conditions for
windshield wipers and blowers, but not for hydrophobic coatings, so it
is necessary to issue special conditions to maintain the level of
safety represented by the current regulations.
These special conditions provide an appropriate safety standard for
the hydrophobic coating technology as the means to maintain a clear
area of vision by requiring it to be effective at low speeds and
precipitation rates as well as the higher speeds and precipitation
rates identified in the current regulation.
Discussion of Comments
Notice of proposed special conditions No. 25-12-07-SC for the
Embraer S.A. Model EMB-550 airplanes was published in the Federal
Register on November 9, 2012, (77 FR 67308). No comments were received,
and the special conditions are adopted as proposed.
As discussed above, these special conditions are applicable to the
Embraer S.A. 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 of airplanes. It is not a rule of general applicability.
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.
Hydrophobic Coatings in Lieu of Windshield Wipers
The airplane must have a means to maintain a clear portion of the
windshield, during precipitation conditions, enough for both pilots to
have a sufficiently extensive view along the ground or flight path in
normal taxi and flight attitudes of the airplane. This means must be
designed to function, without continuous attention on the part of the
flightcrew, in conditions from light misting precipitation to heavy
rain at speeds from fully stopped in still air, to 1.5 VSR1
with lift and drag devices retracted.
Issued in Renton, Washington, on February 4, 2013.
Manager, Transport Airplane Directorate, Aircraft Certification
[FR Doc. 2013-02740 Filed 2-6-13; 8:45 am]
BILLING CODE 4910-13-P