The Valiant had a shoulder-mounted wing and four Rolls-Royce Avon RA.3 turbojet engines, each providing up to 6,500 pounds-force (29 kN) of thrust, installed in pairs in fireproof bays in each wing root.
The design of the Valiant gave an overall impression of a clean aircraft with swept-wing aerodynamics.
George Edwards described the Valiant appropriately and simply as an "unfunny" aircraft.
The root chord thickness ratio of 12% allowed the Avon engines to be within the wing rather than on pods as in the contemporary Boeing B-47.
This "buried engine" installation contributed to the aircraft's aerodynamic cleanness, and was British practice at the time.
It made engine access for maintenance and repair difficult and increased the risk that an uncontained failure of one engine would cause damage to the adjacent engine; it also increased the complexity of the design of the main spar which had to be routed around the engines.

The wing of the Valiant used a "compound sweep" configuration, devised by Vickers aerodynamicist Elfyn Richards.
Richards found that it would be advantageous to increase the sweep on the inboard section of the wing, a discovery which he later patented; the Valiant's wing had 37° sweepback for the inner third of the wing, which reduced to 21° at the tips.
This was because the thickness/chord ratio could be reduced closer to the tips.
The choice to have mild sweepback around the aerodynamic control surfaces meant that in-service speeds were limited to Mach 0.84 and a typical cruise of Mach 0.75 at heights up to 55,000 feet (17,000 m) when lightly loaded.
A drogue parachute was deemed unnecessary even operating from runways as short as 6,000 feet (1,800 m).

The wing was mounted high on the aircraft's fuselage and the placement of the engines and main landing gear within the wing limited the fuel that the wing could carry.
The trailing edge of the wing had two-section ailerons with trim tabs, and inboard of the ailerons were double-slotted flaps.
Direct electrical drives were used to move the flaps and other hydraulically-operated equipment was used.

Production aircraft were powered by four Avon 201 turbojet engines, with 9,500 pounds-force (42 kN) thrust.

In addition to providing thrust for flight, the engines also provided bleed air for the pressurization, ice protection, and air conditioning systems.
The aircraft's DC electrical generators were also driven by the engines.
Napier Spraymat electric heaters were installed in the engine inlets to prevent engine damage due to ice.
The shape of the engine inlets were long rectangular slots in the first prototype, whereas production Valiants had oval or "spectacle" shaped inlets designed to pass greater airflow for the more powerful engines that were installed.
The jet exhausts emerged from fairings above the trailing edge of the wings.

For required takeoff performance from short tropical dispersal bases, a jettisonable rocket booster engines pack was developed for the Valiant.
Trials were performed with two underwing de Havilland Sprite boosters; these were ultimately deemed unnecessary when more powerful variants of the Avon engine became available.
Also, there was an increased risk of accidents if one booster rocket failed on takeoff, resulting in asymmetric thrust.
Some Valiant engines had water injection, which increased takeoff thrust by about 1,000 pounds (450 kg) per engine.

The crew were in a pressurized compartment in the forward fuselage and consisted of a pilot, co-pilot, two navigators, and air signaller (later called an air electronics officer (AEO)).
 Manufacture of this pressurized section was subcontracted to Saunders-Roe.
The pilot and co-pilot were located side-by-side on an upper level, the remaining three crew sat at stations lower in the cockpit, and faced to the rear.
A crew of five had been enabled by the discontinuation of defensive gun turrets and accompanying air gunners, a design philosophy proved by the successful De Havilland Mosquito bomber of World War II.
The pilot and copilot were provided with Martin-Baker Mk.3 ejector seats,
The Valiant had a shoulder-mounted wing and four Rolls-Royce Avon RA.3 turbojet engines, each providing up to 6,500 pounds-force (29 kN) of thrust, installed in pairs in fireproof bays in each wing root. The design of the Valiant gave an overall impression of a clean aircraft with swept-wing aerodynamics. George Edwards described the Valiant appropriately and simply as an "unfunny" aircraft. The root chord thickness ratio of 12% allowed the Avon engines to be within the wing rather than on pods as in the contemporary Boeing B-47. This "buried engine" installation contributed to the aircraft's aerodynamic cleanness, and was British practice at the time. It made engine access for maintenance and repair difficult and increased the risk that an uncontained failure of one engine would cause damage to the adjacent engine; it also increased the complexity of the design of the main spar which had to be routed around the engines.
The wing of the Valiant used a "compound sweep" configuration, devised by Vickers aerodynamicist Elfyn Richards. Richards found that it would be advantageous to increase the sweep on the inboard section of the wing, a discovery which he later patented; the Valiant's wing had 37° sweepback for the inner third of the wing, which reduced to 21° at the tips. This was because the thickness/chord ratio could be reduced closer to the tips. The choice to have mild sweepback around the aerodynamic control surfaces meant that in-service speeds were limited to Mach 0.84 and a typical cruise of Mach 0.75 at heights up to 55,000 feet (17,000 m) when lightly loaded. A drogue parachute was deemed unnecessary even operating from runways as short as 6,000 feet (1,800 m).
The wing was mounted high on the aircraft's fuselage and the placement of the engines and main landing gear within the wing limited the fuel that the wing could carry. The trailing edge of the wing had two-section ailerons with trim tabs, and inboard of the ailerons were double-slotted flaps. Direct electrical drives were used to move the flaps and other hydraulically-operated equipment was used.
Production aircraft were powered by four Avon 201 turbojet engines, with 9,500 pounds-force (42 kN) thrust. 
In addition to providing thrust for flight, the engines also provided bleed air for the pressurization, ice protection, and air conditioning systems. The aircraft's DC electrical generators were also driven by the engines. Napier Spraymat electric heaters were installed in the engine inlets to prevent engine damage due to ice. The shape of the engine inlets were long rectangular slots in the first prototype, whereas production Valiants had oval or "spectacle" shaped inlets designed to pass greater airflow for the more powerful engines that were installed. The jet exhausts emerged from fairings above the trailing edge of the wings.
For required takeoff performance from short tropical dispersal bases, a jettisonable rocket booster engines pack was developed for the Valiant. Trials were performed with two underwing de Havilland Sprite boosters; these were ultimately deemed unnecessary when more powerful variants of the Avon engine became available. Also, there was an increased risk of accidents if one booster rocket failed on takeoff, resulting in asymmetric thrust. Some Valiant engines had water injection, which increased takeoff thrust by about 1,000 pounds (450 kg) per engine.
The crew were in a pressurized compartment in the forward fuselage and consisted of a pilot, co-pilot, two navigators, and air signaller (later called an air electronics officer (AEO)).  Manufacture of this pressurized section was subcontracted to Saunders-Roe. The pilot and co-pilot were located side-by-side on an upper level, the remaining three crew sat at stations lower in the cockpit, and faced to the rear. A crew of five had been enabled by the discontinuation of defensive gun turrets and accompanying air gunners, a design philosophy proved by the successful De Havilland Mosquito bomber of World War II. The pilot and copilot were provided with Martin-Baker Mk.3 ejector seats, 
Vickers Valiant