[Federal Register: November 4, 2005 (Volume 70, Number 213)]
[Notices]               
[Page 67303]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04no05-123]                         



[[Page 67303]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

 
Proposed Advisory Circular 25.21-1X, Performance and Handling 
Characteristics in the Icing Conditions Specified in Part 25, Appendix 
C

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of Availability of Proposed Advisory Circular (AC) 
25.21-1X and request for comments.

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SUMMARY: This notice announces the availability of and requests 
comments on a proposed advisory circular (AC) that provides methods 
acceptable to the Administrator related to the proposed certification 
requirements for performance and handling characteristics of transport 
category airplanes affected by flight in the icing conditions defined 
in appendix C of Title 14, Code of Federal Regulations (CFR) part 25. 
This notice is necessary to give all interested persons an opportunity 
to present their views on the proposed AC.

DATES: Comments must be received on or before January 3, 2006.

ADDRESSES: Send all comments on the proposed AC to: Federal Aviation 
Administration, Attention: Don Stimson, Airplane and Flight Crew 
Interface Branch, ANM-111, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue, SW., Renton, WA 98055-4056. 
Comments may also be submitted electronically to the following address: 
don.stimson@faa.gov. Comments may be inspected at the above address 

between 7:30 a.m. and 4 p.m. weekdays, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Don Stimson at the above address, 
telephone (425) 227-2143; facsimile (425) 227-1320, or e-mail at: 
don.stimson@faa.gov.


SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to comment on the proposed AC by 
submitting such written data, views, or arguments, as they may desire. 
Commenters should identify AC 25.21-1X, and submit comments, in 
duplicate, to the address specified above. The Transport Standards 
Staff will consider all communications received on or before the 
closing date for comments before issuing the final AC. The AC can be 
found and downloaded from the Internet at: http://www.airweb.faa.gov/rgl under 

``Draft Advisory Circulars.'' A paper copy of the proposed AC may be 
obtained by contacting the person named above under the caption FOR 
FURTHER INFORMATION CONTACT.

Harmonization of Standards and Guidance

    The proposed AC is based on recommendations submitted to the FAA by 
the Aviation Rulemaking Advisory Committee (ARAC). The FAA tasked ARAC 
(63 FR 50954, September 23, 1998) to provide advice and recommendations 
on ``harmonizing'' certain sections of part 25 (including section 
25.21) with the counterpart standards contained in Joint Aviation 
Requirements (JAR) 25. The goal of ``harmonization tasks,'' such as 
this, is to ensure that:
    1. Where possible, standards and guidance do not require domestic 
and foreign parties to manufacture or operate to different standards 
for each country involved; and
    2. The standards and guidance adopted are mutually acceptable to 
the FAA and the foreign aviation authorities;
    3. the guidance contained in the proposed AC has been harmonized 
with that of the JAA, and provides a method of compliance that has been 
found acceptable to both the FAA and JAA.

Discussion

    This proposed AC sets forth acceptable methods of compliance with 
the provisions of 14 CFR 25.21 dealing with the certification 
requirements for performance and handling characteristics of transport 
category airplanes affected by flight in icing conditions defined in 
appendix C.
    It is one means, but not the only means, of complying with the 
revisions proposed in Notice No. 05-10 entitled ``Airplane Performance 
and Handling Qualities in Icing Conditions,'' published in this same 
edition of the Federal Register. Issuance of AC 25-21-1 is contingent 
of final adoption of the proposed revisions to part 25. Other methods 
of compliance with the requirements may be acceptable.
    In addition, a separate Notice of Availability of Proposed 
Revisions to AC 25-7A, ``Flight Test Guide for Certification of 
Transport Category Airplanes,'' will be published in the Federal 
Register when issued. In that proposed AC, the FAA proposes removing 
the icing-related guidance from AC 25--7A because that material is 
addressed by the NPRM Notice No. 05-10, ``Airplane Performance and 
Handling Qualities In Icing Conditions'' and proposed AC 25.21-1, 
``Performance And Handling Characteristics In The Icing Conditions 
Specified In Part 25, Appendix C.''

    Issued in Washington, DC, on October 27, 2005.
John Hickey,
Director, Aircraft Certification Service.
[FR Doc. 05-21791 Filed 11-3-05; 8:45 am]

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