Some sites that have information regarding the engine
https://www.federalregister.gov/articles/2008/12/22/E8-29722/airworthiness-directives-general-electric-company-ge-ct7-8a-turboshaft-engines
http://www.geaviation.com/engines/commercial/ct7/ct7-8.html
http://www.thefederalregister.com/d.p/2008-03-19-E8-5492