09/30/2010. Remarks by Johan Visschedijk: "To tackle an envisaged shortage of popular Rolls-Royce Merlin engines, the Bristol Hercules was introduced in the Lancaster B.Mk.II. Eventually the shortage did not materialize, and of the 7,377 Lancasters produced, only 301 were B.Mk.IIs.

The prototype (s/n DT810, first flown November 26, 1941) and the first 26 production aircraft were powered by four 1,650 hp Bristol Hercules VI fourteen-cylinder air-cooled radial engines, the remaining 274 were fitted with Hercules XVI, which featured an A.I.T. 132ME carburetor with automatic mixture strength regulation.

Of all-metal construction, the aircraft carried a crew of seven: Pilot, Navigator, Air Bomber, Wireless Operator, Flight Engineer, and two Air Gunners. The armament consisted of ten 0.303 in (7.7 mm) Browning machine guns, two each in the nose, dorsal, and ventral turrets, and four in the tail turret, while a bomb load of up to 14,000 lb (6,350 kg) could be carried."