Three aircraft were ordered to Specification N.9/47 for a naval fighter, and, configurationally similar to the Type 505 apart from the undercarriage. In February 1950, the contract covering the third prototype was amended to introduce sweptback wings, and this, as the Type 525, became, in effect, the prototype of the Scimitar.
The Type 525 has an all-moving tail with narrow-chord elevators and a tail-braking parachute in the streamlined fairing of the tail-plane and fin. A V-type arrester hook is housed in clamshell doors below the rear fuselage, and there is a fuel tank of 58 gal. capacity in the fuselage between the two jet pipes. The 525 has slotted ailerons, of a similar type to those of the Swift.
Very large flap area is provided for deck-landing, wing flaps being of the chord-increasing type with a slot effect, and extra area is gained by two additional hinged surfaces below the fuselage. The wing also has full-span slats which are extended for slow- speed control. Since the long-stroke undercarriage with its large-diameter wheels retracts into the fuselage for-ward of the flaps, fairing doors for the wheel wells are provided and close to preserve the airflow after the undercarriage is extended. The 525 also has fuselage -mounted air-brake flaps hingeing forward just below the leading edge of the wing on the fuselage.
2 x RR Avon