[Federal Register Volume 65, Number 32 (Wednesday, February 16, 2000)]
[Notices]
[Page 7904]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-3702]



[[Page 7904]]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Advisory Circular; Turbine Engine Power-Loss and Instability in 
Extreme Conditions of Rain and Hail

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of issuance Advisory Circular (AC) on turbine engine 
power-loss and instability in extreme conditions of rain and hail.

-----------------------------------------------------------------------

SUMMARY: This notice announces the issuance of Advisory Circular (AC), 
No. 33.78-1, Turbine Engine Power-Loss and Instability in Extreme 
Conditions of Rain and Hail. This AC may be used to demonstrate 
compliance with the requirements pertaining to Sec. 33.78(a)(2) for 
turbine engines in extreme rain and hail. This AC is meant to provide 
information and guidance concerning an acceptable method, but not the 
only method, for compliance. While guidelines in this AC are not 
mandatory, they are derived from extensive Federal Aviation 
Administration (FAA) and industry experience in determining compliance 
with the requirements.

DATES: Advisory Circular No. 33.78-1, was issued by the New England 
Aircraft Certification Service, Engine and Propeller Directorate on 
February 8, 2000.

FOR FURTHER INFORMATION CONTACT: John Fisher, Engine and Propeller 
Standards Staff, ANE-110, 12 New England Executive Park, Burlington, MA 
01803, telephone (781) 238-7149, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Background

    In 1988, the Aerospace Industries Association (AIA) initiated a 
study of airplane turbine engine power-loss and instability phenomena 
that were attributed to operating in inclement weather. AIA, working 
with the Association European des Constructeurs de Materiel Aerospatial 
(AECMA), concluded that potential flight safety threat exists for 
turbine engines installed on airplanes when operating in an extreme 
rain or hail environment. AIA and AECMA further concluded that the rain 
and hail ingestion requirements contained in Sec. 33.77 did not 
adequately address these threats. Consequently, the Federal Aviation 
Administration (FAA) and the Joint Aviation Authorities (JAA) have 
promulgated additional rain and hail ingestion standards.
    Interested parties were given the opportunity to review and comment 
on the draft AC during the proposal and development phases. Notice was 
published in the Federal Register on September 5, 1996 (61 FR 46893), 
to announce the availability of, and comment to the draft AC.
    This advisory circular, published under the authority granted to 
the Administrator by 49 U.S.C. 106(g), 4113, 44701-44702, 44704, 
provides guidance for these new requirements that were published in the 
Federal Register on March 26, 1998 (63 FR 14794).

    Issued in Burlington, Massachusetts, on February 8, 2000.
Thomas A. Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-3702 Filed 2-15-00; 8:45 am]
BILLING CODE 4910-13-M