This colour plate previously appeared as the cover to part 14.
This week’s cover shows one of the United States Boeing YB-17 heavy bombers during a landing approach with flaps down/ This type of aircraft has four 1,000 horse-power Wright Cyclone nine-cylinder radial air-cooled engines.
The cover was later used as the colour plate with part 34.
THE UPPER COMPONENT of the Short-Mayo composite aircraftMercury, undergoing flight trials at Rochester, Kent, where it was built. Every aircraft has to be passed by Air Ministry pilots before a Certificate of Airworthiness is granted. After certain flight tests have been completed the aircraft has to undergo full-load tests. On its tests the Mercury carried 1,200 gallons of petrol for the full-load separation trails from Maia, the lower component of the Short-Mayo composite aircraft. After the separation 1,000 gallons of petrol had to be jettisoned to permit the Mercury to alight with a light load. Thus the jettisoning valves and the inter-compartment valves of the petrol tank - which runs through the wings - were tested at the same time during the trials.
This plate was used as the cover design for part 14.