05-24157. 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 [phone]; facsimile [phone]; or e-mail at: [e-mail].

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 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.