प्रयागराज एक्सप्रेस - जो भी हो तुम खुदा की कसम; लाजवाब हो

no,its not
a320 has theo speed of 900 kmph at 33000ft,but it can do much more if flown higher
the above screenshot is taken at around 39000ft,so it can fly at that speed,also keep in mind that air gets thinner which results in less drag
if you see click here you will find that sometimes see an a380{mostly dubai australia} flies at high as...
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42000ft
higher altitude also results in fuel efficiency
mostly the speed of aircraft is determined by its mach speed ie speed of sound
the above pics are taken at 0.85 mach,which is 0.15 mach slower than speed of sound at that particular altitude
mach 1= speed of sound at 30000ft{supersonic speed}