Federal Register / Vol. 70, No. 213 / Friday, November 4, 2005 / Notices 67303 

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. 

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: 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] 

BILLING CODE 4910–13–P