Originally Posted by
Lotetu
Good evening,
I'm looking for information about the Mach trim on A320. Any hint welcome.
Thanks
I think you are trying to know about what's known as Mach tuck. This was pronounced on B707 where the beyond certain Mach aircraft pitches down and Mach trim prevents that. Modern aerofoils have much less this phenomenon. In A320 since it is flight path stable aircraft flight control system maintains the flight path by doing whatever it takes even in manual flight. There's no manual trimming unless in direct law.