A High Speed Racing Monoplane which holds Many Long-Distance Flying Records
The aircraft was a twin-engined low-wing monoplane. Retractable undercarriage units were provided which drew up into the engine nascelles. The engines originally fitted to the Comet were De Havilland Gipsy Six of a specially tuned type. These legitimately may be said to have been the forerunners of the Gipsy Six Series II engines which were fitted in the Comets that made some of the later long-distance flights.
Two seats were provided in the fuselage aft of the wings and were fitted with an enclosing cover. Short trailing edge flaps were provided between the fuselage and the engine nascelles. To retract, the wheels moved directly backwards and upwards.
The wings of the Comet tapered towards their tips and had a stressed skin covering on a wooden framework. Plywood covering was used for the wings, which had a final layer of fabric. Similarly the fuselage was a wooden frame covered with plywood. The retractable undercarriage units were hand-operated by a screw jack controlled from the cockpit by a continuous cable. Wheel brakes were also provided.
The MacRobertson Trophy, won
by the Comet in 1934
The special Gipsy Six engines developed 220 horse-power each at 2,350 revolutions a minute at sea level. The petrol tanks had a total capacity of 255 gallons. This supply was carried in two petrol tanks in the forepart of the fuselage and in a small tank behind the cockpit. Engine oil was carried in the engine nascelles. The engines were fitted with automatically-operated two-position variable-pitch airscrews; the pitch was set fine for take-off using a bicycle pump, then coarsened automatically with air pressure as the aircraft climbed.
The initial difference between the special Gipsy Six engines and the standard Gipsy Six Series I engine was in the increased compression ratio. The span of the mail plane was 44 feet, the overall length of the aircraft 29 feet and the overall height nine feet. The maximum permissible all-up weight of the Comet was 5,550 lb. This included an allowance of 400 lb for the crew and their parachutes.
The maximum speed of the aeroplane with full load was 225 miles an hour at sea level, and the cruising speed about 200 miles an hour at 10,000 feet. At this height and speed the maximum range of the aircraft was 2,950 miles; at full throttle at 10,000 feet, and at a speed of 220 miles an hour the range was 2,550 miles. The initial rate of climb was 1,100 feet a minute and the time taken to climb to 10,000 feet 13 minutes. Both these figures were obtained with the airscrew set to fine pitch.
The take-off run was about 450 yards and the landing run about 350 yards, with a load of 5,000 lb. The ceiling of the Comet was 21,000 feet and the absolute ceiling on one engine 4,000 feet. The normal stalling speed of the aircraft with the flaps in use was 78 miles an hour, but with a light load was reduced to 63 miles an hour.
Back in service
Having been built for, and won, the 1934 MacRobertson Trophy Race, DH88 Comet G-ACSS (Grosvenor House) performed various other tasks before ending up in storage during and after WWII. Eventually it was handed over to The Shuttleworth Collection at Old Warden in Bedfordshire as a static exhibit in 1965.
That could have been the end for this classic machine, parked in a hangar as a walk-round exhibit. However, it was restored to former flying glory helped by grants from the Transport Trust and Hawker Siddeley Aviation (the company which had taken over de Havilland's) and from about fifty organisations in the aviation and allied industries.
Grosvenor House flew again in its original colour scheme for the first time in 49 years on Sunday May 17, 1987, and has since proved to be a popular performer at the Old Warden classic displays. One difference between the original and the rebuild - the 1934 Grosvenor House had a tailskid, which on the 'modern' version has been replaced with a tailwheel.
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Sir Geoffrey de Havilland (1882-1965)
By 1908, when the flying of aircraft was just beginning to be noticed in Britain, he persuaded his grandfather to loan him £1,000 from which he could fund the construction of an aeroplane. Along with his assistant, Frank Herle, de Havilland built an engine and a biplane, which were ready to test by 1909.
This aircraft managed to hop a few times before crashing, and so a second machine was built in 1910. This was in the style of a box-kite, typical of the period, and in no way revolutionary, but in 1910 it was one of Britain's few domestically-produced flyable aircraft.
Of the aeroplane, one newspaper reported: "Its speed is great, possibly 30 miles an hour!" The success of this machine, in which de Havilland taught himself to fly, brought him to the attention of the British military which bought his aircraft for £400 and offered him a job at HM Balloon Factory at Farnborough.
At the government factory he produced such aircraft as the FE-2, SE-1, BE-1 and BE-2. In 1914 he joined the Aircraft Manufacturing Company (Airco) as chief designer and test-pilot. Interestingly, he test-flew all of his own designs until 1918.
His most notable achieve-ments at Airco were the DH-4, DH-9 and the DH-10. These aircraft were all considerably larger than the average fighter of the day and gave de Havilland important experi-ence in designing aircraft with high payload capacity. At the end of the First World War, he put this knowledge to use.
Airco folded in 1920 and that same year, in September, de Havilland founded his own company. De Havilland decided to target the commercial market and reject, for the most part, the military one. His factory, first at Stag Lane, Edgeware, and later at Hatfield, produced a steady stream of well-designed, though perhaps not spectacular, biplanes for the civil and commercial markets.
De Havilland's long-time interest in engines led to the creation of the Cirrus 60hp engine using cheap parts from war-surplus Renault engines. The successful mating of this unit to a simple biplane led to the widespread ownership of private aircraft. This plane was the classic DH-60 Moth.
To conserve vital materials during World War II, de Havilland's company designed the Mosquito fighter using less important wood for its structure. The Mossie is considered by some to have been the best all-round aircraft of World War II.
Even before the end of World War II, de Havilland had produced both airframes and engines for early Allied jet fighters. Some D.H. Vampires were still flying at the end of the 20th Century.
Not all of de Havilland's aviation life was happy, though. Two of his three sons were killed in test flying crashes, and in 1966 his company was forced to merge into the Hawker Siddely Group.
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Born the son of a clergyman, de Havilland was the most successful of all British aviation pioneers. Before his 20th birthday he designed a motorcycle and after graduating from the Crystal Palace Engineering School began a short-lived career in the automotive industry.
Moths achieved innumerable aviation awards. De Havilland's aircraft grew increasingly larger during the 1930s, typified by the DH-91 Albatross of 1937 with its 104-ft wingspan. Like many de Havilland aircraft, the Albatross was as much noted for its aesthetic lines as its technical achievement.