[Federal Register Volume 80, Number 65 (Monday, April 6, 2015)]
[Rules and Regulations]
[Pages 18305-18307]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-07713]
========================================================================
Rules and Regulations
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains regulatory documents
having general applicability and legal effect, most of which are keyed
to and codified in the Code of Federal Regulations, which is published
under 50 titles pursuant to 44 U.S.C. 1510.
The Code of Federal Regulations is sold by the Superintendent of Documents.
Prices of new books are listed in the first FEDERAL REGISTER issue of each
week.
========================================================================
Federal Register / Vol. 80, No. 65 / Monday, April 6, 2015 / Rules
and Regulations
[[Page 18305]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2015-0177; Special Conditions No. 25-579-SC]
Special Conditions: Cessna Aircraft Company Model 680A Airplane,
Pilot-Compartment View Through Hydrophobic Windshield Coatings in Lieu
of Windshield Wipers
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions, request for comment.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for the Cessna Model 680A
airplane. This airplane will have a novel or unusual design feature
when compared to the state of technology envisioned in the
airworthiness standards for transport-category airplanes. This design
feature is hydrophobic windshield coatings in lieu of windshield
wipers. 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: This action is effective on Cessna Aircraft
Company on April 6, 2015. We must receive your comments by May 21,
2015.
ADDRESSES: Send comments identified by docket number FAA-2015-0177
using any of the following methods:
Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending
your comments electronically.
Mail: Send comments to Docket Operations, M-30, U.S.
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
Hand Delivery or Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: The FAA will post all comments it receives, without
change, to http://www.regulations.gov/, including any personal
information the commenter provides. Using the search function of the
docket Web site, anyone can find and read the electronic form of all
comments received into any FAA docket, including the name of the
individual sending the comment (or signing the comment for an
association, business, labor union, etc.). DOT's complete Privacy Act
Statement can be found in the Federal Register published on April 11,
2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/ gov/.
Docket: Background documents or comments received may be read at
http://www.regulations.gov/ at any time. Follow the online instructions
for accessing the docket or go to Docket Operations in Room W12-140 of
the West Building Ground Floor at 1200 New Jersey Avenue SE.,
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays.
FOR FURTHER INFORMATION CONTACT: Bob Hettman, ANM-112, Transport
Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue
SW., Renton, Washington 98057-3356; telephone (425) 227-2683; facsimile
(425) 227-1149.
SUPPLEMENTARY INFORMATION:
Background
On January 25, 2012, Cessna Aircraft Company applied for an amended
type certificate for a new Model 680A airplane.
The Model 680A, a derivative of the Cessna Model 680 airplane
currently approved under type-certificate number T00012WI, is intended
to be a nine-passenger executive airplane with a maximum takeoff weight
of 30,300 pounds and a maximum operating altitude of 45,000 feet. The
Model 680A airplane uses a hydrophobic windshield coating, in lieu of
windshield wipers, for an unobstructed outside view from the pilot
compartment.
Type Certification Basis
Under the provisions of Title 14, Code of Federal Regulations (14
CFR) 21.101, Cessna Aircraft Company must show that the Model 680A
airplane meets the applicable provisions of the regulations listed in
type-certificate no. T00012WI, or the applicable regulations in effect
on the date of application for the change except for earlier amendments
as agreed upon by the FAA. The regulations listed in the type
certificate are commonly referred to as the ``original type-
certification basis.''
The certification basis includes certain special conditions,
exemptions, or later amended sections of the applicable part that are
not relevant to these special conditions.
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 680A 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 novel or
unusual design feature, or should any other model already included on
the same type certificate be modified to incorporate the same or
similar novel or unusual design feature, these 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 680A airplane must comply with the fuel-vent and
exhaust-emission requirements of part 34, and the noise-certification
requirements of part 36.
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. 21.101.
Novel or Unusual Design Features
The Cessna Model 680A airplane will incorporate the following novel
or unusual design features:
[[Page 18306]]
The airplane flight-deck design incorporates a hydrophobic
windshield coating that, during precipitation, provides an adequate
outside view from the pilot compartment. Sole reliance on such a
coating, without windshield wipers, constitutes a novel or unusual
design feature for which the applicable airworthiness regulations do
not contain adequate or appropriate safety standards. Therefore,
special conditions are required to provide a level of safety equivalent
to that established by the regulations.
Discussion
Section 25.773(b)(1) requires a means to maintain a clear portion
of the windshield for both pilots of a transport-category airplane to
have a sufficiently extensive view along the flight path during
precipitation conditions. The regulations require this means to
maintain such an area clear vision during heavy-rain precipitation at
airplane speeds up to 1.5 VSR1.
This requirement has existed in principle since 1953 in part 4b of
the ``Civil Air Regulations'' (CAR). Section 4b.351(b)(1) of CAR 4b
required that ``Means shall be provided for maintaining a sufficient
portion of the windshield clear so that both pilots are afforded a
sufficiently extensive view along the flight path in all normal flight
attitudes of the airplane. Such means shall be designed to function
under the following conditions without continuous attention on the part
of the crew: (i) In heavy rain at speeds up to 1.6 VS1, flaps
retracted.''
Effective December 26, 2002, Amendment 25-108 changed the speed for
effectiveness of the means to maintain an area of clear vision from up
to 1.6 VS1 to 1.5 VSR1 to accommodate the
redefinition of the reference stall speed from the minimum speed in the
stall, VS1, to greater than or equal to the 1g stall speed,
VSR1. As noted in the preamble to the final rule for that
amendment, the reduced factor of 1.5 on VSR1 is to maintain
approximately the same speed as the 1.6 factor on VS1.
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 125.213(b) to provide ``a
windshield wiper or equivalent for each pilot station'' has remained
unchanged since at least 1953.
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
conditions 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 existing regulations.
Hydrophobic windshield coatings may depend to some degree on
airflow to maintain a clear-vision area. The heavy rain and high speed
conditions specified in the current rule do not necessarily represent
the limiting condition 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-vision
area of the windshield in low-speed flight or during surface
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 windshield.
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.
The current regulations identify speed and precipitation rate
requirements that represent limiting conditions for windshield wipers
and blowers, but not for hydrophobic coatings. Likewise, 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 the coating to be effective at low speeds
and low precipitation rates, as well as at the higher speeds and
precipitation rates identified in the current regulation. These are the
only new or changed requirements relative to those in Sec.
25.773(b)(1) at Amendment 25-108.
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.
Applicability
As discussed above, these special conditions are applicable to the
Cessna Model 680A airplane. Should Cessna 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 the Cessna Model 680A 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 prior 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 good cause exists for adopting
these special conditions upon publication in the Federal Register. 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 Cessna Model 680A airplanes.
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
[[Page 18307]]
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 March 27, 2015.
Michael Kazycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2015-07713 Filed 4-3-15; 8:45 am]
BILLING CODE 4910-13-P