The first fortnight in August he was due at Martlesham Heath, to fly the Sopwith Antelope through the Air Ministry Competition.
On August 4th, 10th, and 11th, he was to steer Maple Leaf V. in the British International Trophy at Cowes, and on August 2nd he was to drive the 12-cylinder Sunbeam racing car at the Brooklands Meeting.
As it was necessary to spend a good deal of time in practise and trial before each of these events, some idea of the effort required to carry them through may be gathered.
The Air Ministry had offered prizes of £64,000 for speed and reliability of the various types of aircraft, and the Sopwith Aviation Company entered the Antelope, fitted with a Wolseley Viper engine, to compete in the small type of machines. This machine had an enclosed saloon for its two passengers, fitted with two comfortable armchairs, sliding windows, a sliding panel in the roof, by which when sitting in the raised chair one could have the benefit of an open machine if required. A hot and cold air regulator was fitted and also a speaking-tube to the pilot in front.
The tests consisted of slow flying, speed, economy (a comparison between useful load carried, in pounds, not including weight of pilot, oil, and petrol, and the amount of fuel and lubricant consumed), landing and getting-off tests, and self-controlled flights.
In the slow flying test the Antelope got down to 43 miles per hour, the lowest recorded, and in speed attained 110·35 miles per hour, the second best performance. It also put up a good performance in the landing tests in which the machine had to land in a given circle over a row of balloons tethered 50 feet from the ground by means of threads. The Antelope, in landing in 187·7 yards, beat all the others by a good margin, the second being the Westland Napier, taking 235 yards.
In economy the Antelope took second place, and also in the getting-off test, taking 23 feet as against the Westland’s 22·75 feet.
Harry arrived from Cowes on the monoplane and was soon up with the Antelope on the reliability tests, which consisted of two three-and-a-half-hour periods at a speed of not less than 80 miles per hour and at above 3,000 feet up. Harry took Mr. Sopwith as passenger and carried out both periods himself, although a different pilot was allowed for the second three-and-a-half-hour test.
In the uncontrolled test the Antelope flew for five minutes by itself.
The result of these competitions was very hard to judge, the Sopwith and the Westland running very close together, but the official result showed the Westland first, thus winning the prize of £10,000, and the Sopwith gaining the second prize of £3,000.