Emergency AD Issued For PT6 Turbine Blade Failures

Transport Canada issued an emergency Airworthiness Directive (AD) on Feb. 15 mandating the grounding of aircraft equipped with certain Pratt & Whitney Canada (P&WC) PT6 turboprop engines until turbine blade replacements are conducted. 

The move comes as there have been reports of three PT2 blade failures, which were all contained. P&WC says it is investigating the root cause of the failures but in its preliminary investigation, the power turbine modules in all event engines contained newly manufactured part number blades from the same raw material. All had also accumulated less than 25 hours air time since new. 

According to the AD, “Failure of PT2 blades could lead to engine power loss or in-flight shut down, potentially resulting in reduced control of the aeroplane.” 

P&WC parent company RTX said the order affects some 160-180 PT6A and PT6E turboprops. Affected PT2 blades are listed in the AD and “have accumulated less than 50 hours air time since new, or since shop visit, or since second-stage power turbine repair.” 

Operators are required to replace the affected blades “prior to the next flight,” according to the AD.