The "Mach number" is the speed of the aircraft as a percentage of the speed of sound. So an aircraft going at Mach 0.74 is traveling at 74% of the speed of sound. (Mach 0.74 is a typical airliner speed.)
If it is civil , its mach 1.- mach 2 ,name is Concorde & in defence they go beyond mach 2
The speed of a commercial airplane is about 0.8 mach
Mach 3.5 by SR-71.
According to Boeing's website, "the 747-400ER is now the largest and fastest commercial airplane in the sky - cruising at Mach 0.85, or 85 percent of the speed of sound."
An aircraft that flies faster than Mach 1- or about 770 miles an hour at sea level.
Critical Mach Number, or Mcr, refers to the lowest Mach number that air going over and around an aircraft can reach the speed of sound. If an airplane goes over its Mcr, handling might be greatly affected.
A Boeing 787 airplane can travel at the top speed of mach 0.89! Mach 0.89=677 mph The Boeing 787 can reach the top speed of 677 miles per hour!
The SR-71 recon airplane holds that record. Top speed classified, but admitted as at least mach 3.3, The X-15 rocket plane is the very fastest at Mach 6.6, but was purely a research aircraft.
Every airplane has its own speed limits. Most small and commercial planes fly below Mach (the speed of sound). Military fighters and some other planes, like Concorde, fly above Mach, or supersonically.
Mach 1 is the speed at which you break the sound barrier. The speed of sound, or Mach 1, at sea level and under "standard condition" is:1,116.4 ft/s340.3 m/s761.2 mph1,225.1 km/hRead more: How_fast_do_you_have_to_be_moving_to_break_the_sound_barrier
Twice the speed of sound. That's the definition of mach number.Mach number is a more useful measurement of speed than miles per hour in some ways (especially if you're designing an airplane), but not so good for answering questions like "So when are we getting to Denver?" since the speed of sound varies depending on the density of the air.the actual speed of mach 2 is 2472 km/h which is twice mach 1 (1236km/h) at this speed the airplane is roughly 2 meters shorter. planes that can travel this fast are;e111-a ravenmig 25 foxbatf22- raptorf22- strike raptoryf 12a blackbirdconcordef 35 c
* Maximum Speed: 568mph / MACH .86 (913km/h , 439kn) at 35,000 ft. * Maxiumum Cruise Speed: 530mph / MACH .80 (851km/h , 470kn) at 35,000ft. Link: http://en.wikipedia.org/wiki/Boeing_767#Specifications