WASHINGTON—The FAA is proposing mandatory upgrades to Pratt & Whitney PW1500G and PW1900G engines that incorporates a redesigned component developed to eliminate the risk of a condition linked to four inflight shutdowns.
A draft airworthiness directive issued April 4 would require affected operators of the engines, which power Airbus A220s and Embraer E-Jet E2s, to install redesigned compressor intermediate case (CIC) assemblies during the next engine shop visit. The redesigned parts “incorporate a shortened bleed duct configuration” that will prevent acoustic resonance that Pratt determined was causing damage to low-pressure compressor stage 1 rotors.
The issue has been linked to four inflight shutdowns—the most recent occurring in early 2020. Pratt determined that settings in electronic engine control (EEC) software that adjust variable inlet guide vanes to maximize efficiency were contributing to the issue and modified the software. The FAA in 2021 mandated its installation.
Since then, “further analysis” by Pratt determined more work was needed. “The shortened bleed duct will address the unsafe condition by preventing the coincidence between bleed and the acoustic excitation,” the FAA said. “The manufacturer also updated the EEC ... software to provide compatibility with both current and future operation of engines and airplanes with the redesigned CIC assembly installed.”
Comments on the FAA proposal are due May 19.
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