Different airliners are optimized for different cruise speeds, too. Large planes like the 747 and A380 tend to fly faster by default than smaller planes like th

Different airliners are optimized for different cruise speeds, too. Large planes like the 747 and A380 tend to fly faster by default than smaller planes like the 737. A large passenger jet with an airspeed close to Mach 0.9 in strong tail wind can sometimes show ground speed very close to, or even a bit over, what we normally take as Mach 1.