The FAA has proposed an airworthiness directive (AD) for some Pratt & Whitney Canada Corp. turboprop engines to address instances of engine-case perforation caused by the liberation of power-turbine blades and the fracturing or displacement of the power turbine containment ring. Comments will be accepted until March 10, as provided below.
The proposed AD would require installation of a reinforcement liner to the power turbine containment ring, and for certain power turbine containment rings, adding scallops, the FAA said in a Federal Register notice published Jan. 7.
The AD would affect an estimated 1,000 engines of U.S. registry, each engine requiring approximately three hours of labor and parts that cost $1,655.
Transport Canada Civil Aviation, the aviation authority for Canada, issued AD CF-2013-33R1 on Nov. 14, 2013, and notified the FAA of the unsafe condition pursuant to a bilateral agreement. "We are proposing this AD because we evaluated all information provided by Transport Canada Civil Aviation and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design," the FAA said.
Please include "Docket No. FAA-2013-1009; Directorate Identifier 2013-NE-35-AD" at the beginning of your comments. Comments may be submitted until March 10, and may be filed online or mailed to Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.