Originally Posted by
CanadianAirbusPilot
In both those photos, why can't you just bug up to .78 or higher? We run our 321s frequently in smaller margins than that but I find having selected .79 or .80 to be the best way to not worry about it. I would probably not let the plane ride at that low of an airspeed.
I agree. The penetration mach number on the checklist is .76 but it’s definitely not the best course of action at high altitude on an heavy A321. Bette select a higher Mach number sitting nicely in the middle or even closer to MMO that taking the chance to enter the back side of the drag curve in case of sudden moderate/severe turbulence.