FAA has issued airworthiness directive 2021-14-13 for all Pratt & Whitney PW2037s, PW2037Ms, PW2040s and F117-PW-100s, requiring fluorescent penetrant inspections and visual inspections of the high-pressure turbine 2nd-stage air seal assembly and, depending on results, replacement of the 2nd-stage air seal assembly with a part eligible for installation, and this replacement, depending on engine model, must be made at either the next engine shop visit or the next piece-part opportunity, effective Sept. 1, 2021.