Concorde is a tailless aircraft design with a narrow fuselage permitting a 4-abreast seating for 92 to 128 passengers, an ogival delta wing and a droop nose for landing visibility. It is powered by four Rolls-Royce/Snecma Olympus 593 turbojets with variable engine intake ramps, and reheat for take-off and acceleration to supersonic speed. Constructed out of aluminium, it was the first airliner to have analogue fly-by-wire flight controls. The airliner could maintain a supercruise up to Mach 2.04 (2,167 km/h; 1,170 knots; 1,347 mph) at an altitude of 60,000 ft (18.3 km).