[Federal Register Volume 69, Number 130 (Thursday, July 8, 2004)]
[Notices]
[Page 41326]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-15557]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Advisory Circular 25.1419-1A, Certification of Transport Category 
Airplanes for Flight in Icing Conditions

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of issuance of advisory circular.

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SUMMARY: The FAA announces the issuance of Advisory Circular 25.1419-
1A, ``Certification of Transport Category Airplanes in Flight Icing 
Conditions.'' The advisory circular provides guidance for certification 
of airframe ice detection and protection systems on transport category 
airplanes, including a revised description of information that an 
applicant should include in a certification plan.

DATES: AC 25.1419-1A was issued by the FAA Transport Airplane 
Directorate in Renton, Washington, on May 7, 2004.
    How To Obtain Copies: A copy of Advisory Circular 25.1419-1A can be 
downloaded from the Internet at http://www.airweb.faa.gov/rgl. A paper 
copy will be available in approximately 6-8 weeks from the U.S. 
Department of Transportation, Subsequent Distribution Office, M-30, 
Ardmore East Business Center, 3341 Q 75th Avenue, Landover, MD 20795.

FOR FURTHER INFORMATION CONTACT: Pat Siegrist, FAA Standardization 
Branch, ANM-113, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056; telephone (425) 227-2126.

Background

    Paragraph 3, Analyses, of AC 25.1419-1A, describes information that 
should be included in a certification plan submitted by the applicant.
    Applicants have erroneously thought this note allowed adequate 
analysis and testing to preclude the requirement for flight test 
demonstrations. However, 14 CFR 25.1419(b) at amendment level 25-72 
requires flight testing in natural icing conditions as a means to 
verify the analyses required by paragraph (a) to check for icing 
anomalies, and to demonstrate that the ice protection system and its 
components are effective. Guidance material may not supersede the rule 
and, therefore, Note 2 does not preclude the need for flight testing in 
natural icing conditions.
    As part of a new type certification program, flight in natural 
icing conditions is required to show compliance with Sec.  25.1419(b). 
In addition to flight in natural icing conditions, additional wind 
tunnel, laboratory, and other flight tests may be required to verify 
the analyses required by Sec.  25.1419(a). However, under some 
circumstances, flight test data acquired on a previous certification 
program may be found to be applicable to a new or modified airplane 
(such a derivative model). To use the previous flight test data, the 
applicant is required to provide supporting data and rationale that 
show:
    a. The original flight test data is applicable (similarity).
    b. The applicant possesses the flight test data.
    c. The new or modified configuration is safe for flight in icing 
conditions.
    Because of the erroneous interpretations, the AC has been revised 
to provide further clarification of this issue.

    Issued in Renton, Washington, on May 7, 2004.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-15557 Filed 7-7-04; 8:45 am]
BILLING CODE 4910-13-M