[Federal Register Volume 67, Number 191 (Wednesday, October 2, 2002)]
[Notices]
[Pages 61947-61948]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-25053]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Proposed Advisory Circular; Continued Airworthiness Assessments 
of Powerplant and Auxiliary Power Unit Installations on Transport 
Category Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of availability of proposed advisory circular and 
request for comments.

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SUMMARY: This notice announces the availability of proposed Advisory 
Circular (AC) No. 39.XX, Continued Airworthiness Assessments of Power 
plant and Auxiliary Power Unit Installations on Transport Category 
Airplanes.

DATES: Comments must be received on or before November 1, 2002.

ADDRESSES: Send all comments on the proposed AC to the Federal Aviation 
Administration, Attn: Engine and Propeller Standards Staff, ANE-110, 
Engine and Propeller Directorate, Aircraft Certification Service, 12 
New England Executive Park, Burlington, MA, 01803-5299.

FOR FURTHER INFORMATION CONTACT: Ann Azevedo, Engine and Propeller 
Standards Staff, ANE-110, at the above address, telephone (781) 238-
7117, fax (781) 238-7199. A copy of the subject AC may also be obtained 
electronically by writing to the following Internet address: 
[email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    A copy of the subject AC may be obtained by contacting the person 
named under FOR FURTHER INFORMATION CONTACT or by downloading the 
proposed AC from the following Internet website: http://www.airweb.faa.gov/rgl. The FAA invites interested parties to comment 
on the proposed AC. Comments should identify the subject of the AC and 
be submitted to the individual identified under FOR FURTHER INFORMATION 
CONTACT. The FAA will consider all communications received by the 
closing date before issuing the final AC.

Background

    The proposed Advisory Circular (AC) describes the Continued 
Airworthiness Assessment Methodologies (CAAM). The Federal Aviation 
Administration (FAA) Engine and Propeller Directorate (EPD) and the 
Transport Airplane Directorate (TAD) may use CAAM to identify unsafe 
conditions and

[[Page 61948]]

determine when an ``unsafe condition is likely to exist or develop in 
other products of the same type design'' before prescribing corrective 
action in accordance with Title 14 of the Code of Federal Regulations 
(14 CFR) part 39. CAAM is used for products associated with the 
Powerplant or Auxiliary Power Unit (APU) Installations on Transport 
Category Airplanes.
    Continued airworthiness requires that safety concerns within the 
existing fleet be addressed, and the knowledge gained applied for the 
benefit of future fleets as well. This proposed AC also provides CAAM 
guidance for estimating the risks associated with identified unsafe 
conditions; defining prioritizing, and selecting suitable corrective 
actions for all identified unsafe conditions; and verifying that the 
corrective actions were effective. This proposed AC is intended to 
present a tangible means of logically assessing and responding to the 
safety risks posed by unsafe conditions.
    This proposed AC does not establish any requirement that the FAA 
must perform a risk assessment before issuing an AD, or that the FAA 
must wait to issue an AD until the design approval holder performs a 
risk assessment, or that the FAA must accept the findings of a risk 
assessment performed by the design approval holder. CAAM, as described 
in this proposed AC, assists the FAA in making decisions concerning the 
priority in which unsafe conditions should be addressed. The FAA may 
issue an AD for a particular unsafe condition before a risk assessment 
is performed, or without having an assessment performed at all.
    In this regard, CAAM does not define ``unsafe condition'' in a 
powerplant or APU installation. Rather, CAAM is a tool that the FAA 
usually will sue to make the kinds of decisions described above.
    Note that the descriptive level of the CAAM process contained in 
this AC is aimed at the individual, whether from the FAA or the 
manufacturer, who is without extensive risk analysis experience. Some 
of the material within this AC will therefore seem very basic to the 
experienced analyst. Additionally, this proposed AC recognizes that an 
analysis must sometimes be performed without the benefit of readily-
available information from the manufacturer. Typically, it is expected 
that more specific information will be available to the analyst, thus 
eliminating the need for some of the process steps that are described.
    While information may be provided by and the assessment performed 
by the applicant, decisions as to whether an unsafe condition exists, 
and the appropriate responses to that unsafe condition, are exclusively 
the responsibility of the Administrator.
    This proposed advisory circular, published under the authority 
granted to the Administrator by 49 U.S.C. 106(g), 40113, 44701-44702, 
44704, provides guidance for the use of CAAM.

    Dated: Issued in Burlington, Massachusetts, on September 24, 
2002.
Francis Favara,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 02-25053 Filed 10-1-02; 8:45 am]
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