https://airleasereviewblog.com/2016/06/19/engine-thrust-at-delivery-and-return/ https://airleasereviewblog.com/2016/06/19/engine-thrust-at-d... It seems like a

https://airleasereviewblog.com/2016/06/19/engine-thrust-at-delivery-and-return/ https://airleasereviewblog.com/2016/06/19/engine-thrust-at-d... It seems like a system that can't be easily changed mid flight and it's leased from the manufacturer as an alternative to buying the 'upgrade'.