Bombardier-Learjet

Pratt and Whitney Canada Corp. has provided Learjet with information that establishes an ending applicability for this proposed Airworthiness Directive for PW305A engines. According to an email from Edward Cox - PW300 Project Engineering, "any engine from CA0651 forward will be linked to the updated MM with the 7,000cy exducer life limit." Therefore, on behalf of Bombardier-Learjet, I request that the FAA validate this information with Pratt and Whitney and establish an ending serial number applicability for the proposed AD because engines that have entered/will enter service with the appropriate Airworthiness Limitations already included in their EMM will not be subject to this unsafe condition. To leave the AD applicability open ended would cause hours of unnecessary review and log book entries for OEMs and operators of engines that do not have an unsafe condition.