longer range missions would sometimes be flown with only a crew of two. A prone position for bombing missions was also provisioned for, which included a watertight hatch and a hinged course-setting bomb sight. The bomb fusing controls were placed within reach of both the pilot and observer positions; ammunition was stowed in ten ammunition pans within the gunner's cockpit. Armament consisted of one fixed, forward-firing .303 in (7.7 mm) Vickers machine gun, plus a .303 in (7.7 mm) Vickers K machine gun or Lewis Gun mounted on a Scarff ring in the rear cockpit, with provision for a torpedo or equivalent bombload carried externally. The fuselage was strengthened to withstand catapult launches and divided into watertight compartments. Structural elements included stainless steel tubular spars and light alloy ribs; similar materials were used for the entire tail section save for the Alclad-plated fin. The majority of the flying surfaces had fabric coverings; the wing tips were detachable as to allow their easy replacement if damaged. The main fuel tanks were not integral to the structure; instead, two detachable tanks composed of duralumin were carried in separate watertight compartments forward of the pilot, housing up to 182.5 gallons of fuel. The aircraft had a range of 623 miles normally, but this could be extended to 1,130 miles via the use of a cylindrical tank, attached to the torpedo crutches, that was capable of holding up to 150 gallons of additional fuel. Into flight On 24 August 1933, Blackburn's B-6 prototype, powered by with a Armstrong Siddeley Tiger IV engine, made its maiden flight at Brough. Following the completion of manufacturer trials, during which the engine was enclosed in a long-chord cowling, this prototype was delivered to the Aeroplane and Armament Experimental Establishment (A&AEE) at RAF Martlesham Heath for an official performance evaluation on 26 November 1933. During the following year, after the conclusion of testing at Martlesham, it was transferred to Gosport ahead of deck landing trials on board the aircraft carrier . These having been deemed successful as well, the prototype was taken up by the Directorate of Technical Development. During August 1934, Blackburn received an initial production order for 16 aircraft to be produced for the FAA. One month later, limited production had already commenced. During October 1934, the name Shark I was officially sanctioned; around this time, a series of modifications were implemented, the most visible of which