[Federal Register Volume 70, Number 242 (Monday, December 19, 2005)]
[Notices]
[Pages 75235-75236]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-24157]


-----------------------------------------------------------------------

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; extension of comment period.

-----------------------------------------------------------------------

SUMMARY: This notice announces the extension of the comment period for 
Notice of availability of proposed Advisory Circular (AC) 25.21-1X, and 
request for comments, which was published in the Federal Register on 
November 4, 2005 (70 FR 67303), and closes on January 3, 2006. In that 
notice, the FAA invited public comment on a proposed AC which provides 
guidance on a means, but not the only means, of compliance with 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 extension of the comment period 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 February 2, 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 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 (206) 227-2143; facsimile (425) 227-1320; or e-mail at: 
[email protected].

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.

Background

    This proposed AC sets forth acceptable methods of compliance with 
the provisions of 14 CFR 25.21 and related regulations 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 the Federal 
Register on November 4, 2005 (70 FR 67278). Issuance of AC 25-21-1 is 
contingent on 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

[[Page 75236]]

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 25.21-1X, 
``Performance And Handling Characteristics In The Icing Conditions 
Specified In part 25, Appendix C.''
    Since publication of that notice, the FAA has received a request 
that the comment period for the notice be extended past its original 
closing date of January 3, 2006, to allow more time in which to study 
the proposal and to prepare comments on this very important issue.

Extension of Comment Period

    The FAA has reviewed the request for consideration of an additional 
amount of time to comment on proposed AC 25.21-1X, and has determined 
that extending the comment period would be in the public interest and 
that good cause exists for taking this action. Accordingly, the comment 
period of Notice of availability of proposed AC 25.21-1X, and request 
for comments, is extended until February 2, 2006.

    Issued in Renton, Washington, on December 9, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate Aircraft Certification Service.
[FR Doc. 05-24157 Filed 12-16-05; 8:45 am]
BILLING CODE 4910-13-M