There's been an awful lot written about production issues at Boeing and Pratt & Whitney over the last couple of years relating to production and quality issues on the B737MAX, B787, and the Geared Turbo Fan programs.  But it isn't bad news for all members of the commercial aviation ecosystem, and aviation Maintenance, Repair, and Overhaul (MROs) as well as sellers of Used Serviceable Materials (USM) have seen robust business trends. This has happened as a result of programmatic quality and production issues, as well as the recovery from the impact of the COVID-19 pandemic on air travel (passenger traffic is now testing pre-pandemic peaks).  

How long will this trend last?  Given the magnitude of the production issues on the B737MAX and the Geared Turbo Fan, I expect to see above normal demand for MRO and USM for the B737NG, Airbus CEO (old engine option), and CFM56-5/7 for at least another 18 to 24 months while Pratt and Boeing resolve their respective production issues.  There is a silver lining in every cloud.