[Federal Register Volume 76, Number 101 (Wednesday, May 25, 2011)]
[Proposed Rules]
[Pages 30294-30295]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-12943]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM457; Notice No. 25-11-14-SC]


Special Conditions: Gulfstream Aerospace LP (GALP) Model G250 
Airplane Pilot Compartment View--Hydrophobic Coatings in Lieu of 
Windshield 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 Gulfstream 
Aerospace LP (GALP) Model G250 airplane. This airplane will have a 
novel or unusual design feature associated with the pilot-compartment 
view through a hydrophobic windshield coating, in lieu of windshield 
wipers. 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 July 11, 2011.

ADDRESSES: You must mail two copies of your comments to: Federal 
Aviation Administration, Transport Airplane Directorate, Attn: Rules 
Docket (ANM-113), Docket No. NM457, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356. You may deliver two copies to the Transport 
Airplane Directorate at the above address. You must mark your comments: 
Docket No. NM457. 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: Loran Haworth, Transport Airplane 
Directorate, Aircraft Certification Service, 1601 Lind Avenue, SW., 
Renton, Washington 98057-3356; telephone (425) 227-1133; facsimile 
(425) 227-1149.

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 7:30 a.m. and 4:00 p.m., Monday through Friday, except Federal 
holidays.
    We will consider all comments we receive on or before the closing 
date for comments. We may change these special conditions based on the 
comments we receive.
    If you want us to acknowledge receipt of your comments on this 
proposal, include with your comments a self-addressed, stamped postcard 
on which you have written the docket number. We will stamp the date on 
the postcard and mail it back to you.

Background

    On March 30, 2006, GALP applied for a type certificate for their 
new Model G250 airplane. The G250 is an 8-10 passenger (19 maximum), 
twin-engine airplane with a maximum operating altitude of 45,000 feet 
and a range of approximately 3,400 nautical miles. Airplane dimensions 
are 61.69-foot wing span, 66.6-foot overall length, and 20.8-foot tail 
height. Maximum takeoff weight is 39,600 pounds and maximum landing 
weight 32,700 pounds. Maximum cruise speed is mach 0.85, dive speed is 
mach 0.92. The avionics suite will be the Rockwell Collins Pro Line 
Fusion.
    The Model G250 airplane incorporates novel or unusual design

[[Page 30295]]

features involving hydrophobic window coatings in lieu of windshield 
wipers.

Type Certification Basis

    Under the provisions of 14 CFR 21.17, GALP must show that the Model 
G250 airplane meets the applicable provisions of part 25 as amended by 
Amendments 25-1 through 25-117.
    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 G250 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, the special conditions would also apply to the 
other model.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model G250 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 Model G250 will incorporate the following novel or unusual 
design features:
    The GALP Model G250 airplane flight-deck design incorporates a 
hydrophobic coating to provide adequate pilot-compartment view in the 
presence of precipitation. 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 that provide the level of safety equivalent to that 
established by the regulations.

Discussion

    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. 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 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.

Applicability

    As discussed above, these special conditions are applicable to the 
GALP Model G250 airplane. Should GALP 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 GALP Model G250 airplane. It is not a rule of general 
applicability and it affects only the applicant who applied to the FAA 
for approval of these features on the airplane.

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 the GALP Model G250 airplane.
    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 
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 May 19, 2011.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-12943 Filed 5-24-11; 8:45 am]
BILLING CODE 4910-13-P