Concerned about an increased rate of in-flight shutdowns (IFSDs) of PW305A engines powering Bombardier Learjet 60s, Transport Canada has issued a civil aviation safety alert (CASA) advising operators to follow Pratt & Whitney Canada service instructions for upgrades to remedy the situation. Released last week, the CASA cites “a notable increase in engine IFSD events” that were attributed to failures of electronic engine control (EEC) units manufactured by Smiths (P/N 31B4741/vendor P/N 1240KDC).
The affected parts are on Learjet 60 S/N 001 to 128. Bombardier produced 400 Learjet 60s in all from 1991 to 2012.
A P&WC investigation found that the in-flight shutdowns stemmed from aging-related issues associated with internal components of the EECs. Compounding the issue is the fact that P&WC support for the repair of the older EEC units will not be available in the near future, Transport Canada said. As a result, P&WC issued a Service Information Letter (SIL) PW300-201 recommending an upgrade of the EEC to the latest configuration in line with its service bulletin PW300-72-24434.
“Transport Canada recommends that owners, operators, and maintainers of the affected PW305A engines familiarize themselves with P&WC’s SIL PW300-201 and follow the recommendations therein,” the agency said.