[Federal Register Volume 64, Number 189 (Thursday, September 30, 1999)]
[Pages 52819-52820]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25456]



Federal Aviation Administration

Proposed Advisory Circular 25-XX, Transport Airplane Propulsion 
Engine and Auxiliary Power Unit Installation Certification Handbook--
The Propulsion Mega AC

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of availability of proposed Advisory Circular (AC) 25-XX 
and request for comments.


SUMMARY: This document announces the availability of and requests 
comment on a proposed advisory circular (AC) that provides guidance on 
methods acceptable to the Administrator for showing compliance with the 
type certification requirements for propulsion engine and auxiliary 
power unit (APU) installations as they apply to transport category 
airplanes. This notice is necessary to give all interested persons an 
opportunity to present their views on the proposed AC.

DATE: Comments must be received on or before December 29, 1999.

ADDRESS: Send all comments on the proposed AC to: Federal Aviation 
Administration (FAA), Attention: Steve Happenny, Propulsion/Mechanical 
Systems Branch, ANM-112, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98055-
4056. Comments may be inspected at the above address between 7:30 a.m. 
and 4:00 p.m. weekdays, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Jill DeMarco, Program Management 
Branch, ANM-114, FAA, Transport Airplane Directorate, 1601 Lind Avenue 
SW., Renton, Washington 98055-4056; telephone (425) 227-1313; fax (425) 


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 must identify the AC by title and submit comments in 
duplicate to the address specified above. The Transport Airplane 
Directorate of the Federal Aviation Administration (FAA) will consider 
all communications received on or before the closing date for comments 
before issuing the final AC.

Availability of Proposed AC

    The proposed AC can be found and downloaded from the Internet at 
http://www.faa.gov/avr/air/airhome.htm, at the link titled ``Draft 
Advisory Circulars.''
    Requests for copies should be directed to the person named above 
under the caption FOR FURTHER INFORMATION CONTACT. Please specify 
whether a paper copy or a CD-ROM (Microsoft Word Version 6.0/Windows 95 
format) copy is needed. Because of the large size of this proposed AC 
(approximately 1,200 pages) and the time necessary for copying the 
document, expect extra time for fulfilling requests for paper copies.


    The proposed advisory circular (AC) provides one comprehensive 
source of FAA policy and guidance on various methods acceptable to the 
Administrator for showing compliance with the type certification 
requirements for propulsion engine and auxiliary power unit (APU) 
installations on transport category airplanes.
    The proposed AC contains information and material concerning all 
facets of propulsion system certification that have been derived from 
various sources, such as:
     Title 14, Code of Federal Regulations (commonly referred 
to as the Federal Aviation Regulations),
     FAA Issue Papers,
     Special Conditions,
     Technical Standard Orders (TSO),
     FAA internal policy memos,
     FAA technical reports,
     documents issued by the Society of Automotive Engineers 
(SAE), and
     General Aviation Manufacturers Association (GAMA) 
    The material contained in the proposed AC is intended for use 
during propulsion certification activities by airplane manufacturers, 
modifiers, foreign regulatory authorities, and Federal Aviation 
Administration (FAA) airplane type certification engineers. The policy 
and guidance provided in the document has been applied previously and 
found to be acceptable to the FAA for demonstrating compliance with the 
certification regulations pertaining to propulsion (engine and APU) 
installations on transport category airplanes. The methods and 
procedures described have evolved through many years and represent 
current certification practice.
    The FAA's objective in issuing this AC is to formalize existing 
policy and guidance so that the public and FAA

[[Page 52820]]

personnel have access to this information in one document. In gathering 
all relevant material into one document, the consequent size of the 
proposed AC is necessarily large; for this reason, the informal title 
of ``The Propulsion Mega AC'' is used throughout the document to 
distinguish it from others that are referenced.

    Issued in Renton, Washington, on September 23, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
[FR Doc. 99-25456 Filed 9-29-99; 8:45 am]