At cruise altitude (35,000-40000 feet) it goes at Mach 0.85 (that is to say, 85% of the speed of sound) which translates in a ground speed of about 570 mph or 915 km/h, but it can go as fast as Mach 0.92 (614 mph, 988 km/h) should the need arise.
â¢ VAST (adjective). The adjective VAST has 1 sense: 1. unusually great in size or amount or degree or especially extent or scope. Familiarity information: VAST used as an adjective is very rare.
syn: huge, enormous, tremendous, immense imply great magnitude. huge, when used of concrete objects, usu. adds the idea of massiveness, bulkiness, or even lack of shape: a huge mass of rock. enormous applies to what exceeds a norm or standard in extent, magnitude, or degree: an enormous iceberg. tremendous suggests something so large as to be astonishing or to inspire awe: a tremendous amount of equipment.