Sixto, isn't it the case that the earth rotates in the same direction that you were going on a flight from asia? That would mean that your speed in relation to the surface of the earth was much less than 704 mph - in fact, you may have been going backward!
The C5 is bigger, but the 747 weighs a little more. Keep in mind that there are now several reiterations of 747 which is continually being modified to fend off the market intrusion of competitors, notably the Airbus A380 which is another big boy.
All of them are too tubby to fly - defies logic and basic rules of physics. They must come down. Save yourself by staying well away from such monstrosities!!