How fast can a 777 go whilst maintaining structural integrity?

Question

Assume the 777 has unlimited power.

Answer 1

900km/h

Answer 2

a 777 under its own power without  being in a dive will never reach such a speed that it will break up. stresses will develop in the structure but nothing will separate.

Max operating speed for a 777 is .86 mach. flying any extended period of time past this speed will cause stresses in the structure. for break-up speed, no one really knows because no one actually tested it. however, we can safely assume that it is past .86mach and less than mach 1 give or take 0.01-0.03 (aircraft might exceed mach 1 while breaking up---after WWII, this has happened)

an aircraft not designed for supersonic flight will start to shake, become unstable, and eventually break up. we know this since the era when Chuck Yeager broke the sound barrier.

I would guess around mach 0.95 to 1.00 for the 777. A 747 once entered an uncontrollable dive and reached mach 0.95 without breaking up to a point of becoming  unairworthy. (check records for japan airlines 747-200)

Answer 3

that has never been tested. they only do a structural load test for the wings where they bend it till it breaks and it was found to exceed the required limit by about 150%. aircraft (not the B777) that have crashed have dive bombed at speeds in excess of mach 1 before breaking up. that's about the best info as we can get.