[Federal Register: July 12, 2006 (Volume 71, Number 133)]
[Proposed Rules]
[Page 39235-39237]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr12jy06-21]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM348; Notice No. 25-06-07-SC]
Special Conditions: Dassault Aviation Model Falcon 7X Airplane,
Windshield Coating in Lieu of Wipers
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
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SUMMARY: This action proposes special conditions for the Dassault
Aviation Model Falcon 7X airplane. This airplane will have a novel or
unusual design feature(s) associated with use of a hydrophobic coating,
rather than windshield wipers, as the means to maintain a clear portion
of the windshield during precipitation conditions, as required by the
airworthiness standards for transport category airplanes. The
applicable airworthiness regulations do not contain adequate or
appropriate safety standards for this design feature. These proposed
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: We must receive your comments by August 28, 2006.
ADDRESSES: You must mail two copies of your comments to: Federal
Aviation Administration, Transport Airplane Directorate, Attn: Rules
Docket (ANM-113), Docket No. NM348, 1601 Lind Avenue, SW., Renton,
Washington 98057-3356. You may deliver two copies to the Transport
Airplane
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Directorate at the above address. You must mark your comments: Docket
No. NM348 You can inspect comments in the Rules Docket weekdays, except
Federal holidays, between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: John McConnell, Airplane and Flight
Crew Interface Branch, ANM-111, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-1365; facsimile (425) 227-
1320, e-mail john.mcconnell@faa.gov.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite interested people to take part in this rulemaking by
sending written comments, data, or views. The most helpful comments
reference a specific portion of the special conditions, explain the
reason for any recommended change, and include supporting data. We ask
that you send us two copies of written comments.
We will file in the docket all comments we receive, as well as a
report summarizing each substantive public contact with FAA personnel
concerning these special conditions. You can inspect the docket before
and after the comment closing date. If you wish to review the docket in
person, go to the address in the ADDRESSES section of this preamble
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays.
We will consider all comments we receive on or before the closing
date for comments. We will consider comments filed late if it is
possible to do so without incurring expense or delay. We may change
these special conditions based on the comments we receive.
If you want the FAA to acknowledge receipt of your comments on this
proposal, include with your comments a pre-addressed, stamped postcard
on which the docket number appears. We will stamp the date on the
postcard and mail it back to you.
Background
On June 4, 2002, Dassault Aviation applied for a type certificate
for its new Model Falcon 7X airplane. The Model Falcon 7X is a 19
passenger transport category airplane, powered by three aft mounted
Pratt & Whitney PW307A high bypass ratio turbofan engines. Operation of
the airplane is accomplished using a fly-by-wire (FBW) primary flight
control system. This will be the first application of a FBW primary
flight control system in a private/corporate use airplane.
The Dassault Aviation Model Falcon 7X flightdeck design
incorporates a hydrophobic coating to provide adequate pilot
compartment view in the presence of precipitation. Primary 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 that provide the level of
safety equivalent to that established by the regulations.
Type Certification Basis
Under the provisions of 14 CFR 21.17, Dassault Aviation must show
that the Model Falcon 7X airplane meets the applicable provisions of
part 25, as amended by Amendment 25-1 through Amendment 25-108 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 Falcon 7X because of a novel
or unusual design feature, special conditions are prescribed under the
provisions of Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Model Falcon 7X 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 Sec. 11.19, under
Sec. 11.38, and they become part of the type certification basis under
Sec. 21.17(a)(2).
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.
Novel or Unusual Design Features
The Model Falcon 7X will incorporate the following novel or unusual
design feature:
Hydrophobic windshield coating as the primary means to maintain a
clear portion of the windshield, during precipitation conditions,
sufficient for both pilots to have a sufficiently extensive view along
the flight path.
Discussion
Section 25.773(b)(1) requires that both pilots of a transport
category airplane be provided a means to maintain a sufficiently clear
portion of the windshield during precipitation conditions, and that
this clear portion of the windshield must have a sufficiently extensive
view along the flight path. The regulations require this means to
maintain such an area during precipitation in heavy rain at 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 1-g stall speed, VSR1, as the 1-g stall speed. 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 in 14 CFR 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
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of safety embodied in the existing regulations.
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
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.
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. These are the only new or
changed requirements relative to those in Sec. 25.773(b)(1) at
Amendment 25-108.
Applicability
As discussed above, these special conditions are applicable to the
Model Falcon 7X. Should Dassault Aviation 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 airplane. 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 Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for Dassault Aviation Model Falcon 7X airplanes.
Pilot Compartment View--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 flight path in normal
flight attitudes of the airplane. This means must be designed to
function, without continuous attention on the part of the crew, 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 July 3, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E6-10894 Filed 7-11-06; 8:45 am]
BILLING CODE 4910-13-P