Part 21 of Wonders of World Aviation was published on Tuesday 26th July 1938, price 7d.
This part was the first in volume 2. It included a colour plate (acting as the frontispiece to volume 2) showing a Hawker Hind diving. This had previously appeared as the cover to Part 20.
This week’s cover shows one of the six Shark aeroplanes built by The Blackburn Aircraft Ltd, at Brough, Yorkshire, for the Portugues Navy. The Blackburn Shark bomber-reconnaissance seaplane is a staggered folding biplane, with a metal monocoque fuselage. The span is 46 feet, the length 35 ft 2 in, and the height 12 ft 1 in. The aircraft is powered by a 670- 700 horse-power Armstrong Siddeley fourteen-cylinder radial air-cooled engine. The maximum speed is 152 miles an hour at 5,500 feet and the alighting speed is 62 miles an hour.
THE SYNCHRONIZED GUNS fire through the propeller of the Hawker Hind, a light day bomber used in the Royal Air Force. These guns are accommodated in slots in the nose cowling of the aircraft. A third gun with flexible mounting is provided for the back cockpit to protect the machine from behind. Bomb racks are fitted on both sides of the fuselage below the bottom wings. Two 250-lb bombs can be carried, or a larger number of smaller ones. The pilot aims his two guns by pointing the aeroplane in the direction in which he wishes to fire. The Hawker Hind has a 640 horse-power Rolls-Royce Kestrel V water-cooled engine which gives the aeroplane a maximum speed of 187 miles an hour. The engine radiator is of the retractable type and is slung beneath the fuselage in front of the undercarriage.