[BwanaNdege]

It takes a specially thick reinforced runway long enough to take off again and there ain’t to many of em around the world 7 feet thick with concrete.

For reference, Boeing has a limit of a 6000 foot runway for Boeing-operated 777 operations.

The 777 has a lower landing weight than the 747, which lands all over the world.

The "7 feet of concrete" might be needed for landing, not so much for takeoff.

http://www.boeing.com/assets/pdf/commercial/airports/faqs/boeing_pavement_surface_types.pdf

"Rigid Pavement- A runway, taxiway, or ramp that is surfaced with a mixture of concrete materials (Portland cement, sand, coarse aggregate, and water) of from 6 to 20 inches (15 to 51 centimeters) or more in thickness. Typical narrow body runways usually have 11 to 13 inches (28 to 33 centimeters) of concrete thickness, and runways that serve wide body aircraft usually have 17 to 20 inches (43 to 51 centimeters) of concrete thickness. This type of construction qualifies a runway to be referred to as "hard surfaced" or "paved". (Also known as a "concrete" pavement.)"

[pansgold]

Perhaps I misspoke on the dimensions. Being a former airman in the military, I know the C5A Galaxy needs a 7,000 foot runway 7 feet thick. I have not com paired the size of the 777 to the C5A but they are both HUGE as is the A380.

The weight of the plane plus cargo , fuel and passengers is in the 100 ton range.