Proposed Advisory Circular; Instructions for Continued Airworthiness: Focused Inspection of Safety Critical Turbine Engine Parts at Piece-Part Opportunity

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

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

SUMMARY:

This notice announces the availability of draft Advisory Circular (AC) No. 33.4-2, Instructions for Continued Airworthiness: Focused Inspection of Safety Critical Turbine Engine Parts at Piece-Part Opportunity.

DATES:

Comments must be received on or before May 16, 2000.

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:

Mark Liptak, Engine and Propeller Standards Staff, ANE-110, at the above address, telephone (781) 238-7749, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

A copy of the subject AC may be obtained by contacting the person named above under FOR FURTHER INFORMATION CONTACT or by downloading the draft AC from the following Internet website: www.faa.gov/avr/air/acs/draftach.htm. Interested persons are invited to comment on the proposed AC and to submit such written data, views, or arguments as they desire. Commenters must identify the subject of the AC and submit comments in duplicate to the address specified above. All communications received on or before the closing date for comments will be considered by the Engine and Propeller Directorate, Aircraft Certification Service, before issuance of the final AC.

Background

This proposed AC provides guidance and acceptable methods, but not the only methods, that may be used to demonstrate compliance with the requirements of 14 CFR 33.4, Instructions for Continued Airworthiness (ICA), relating to focused inspections of safety critical turbine engine parts. Analysis of ten years of transport aircraft accident and incident data shows that the leading turbine engine unsafe condition is the uncontained failure of safety critical parts. The failure of safety critical parts can present a significant hazard to an aircraft by releasing fragments that can penetrate the cabin or fuel tanks, damage control surfaces, or sever flammable fluid or hydraulic lines. To reduce the occurrence of these incidents, parts and part features most critical to safety should be subjected to focused inspections at piece-part opportunities, using methods that detect flaws that could lead to failure.