de Havilland DH.88
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|G-ACSS Grosvenor House on display at the Farnborough Air Show in September 1988|
|Status||Two in restoration|
The de Havilland DH.88 Comet was a twin-engined British aircraft designed for the 1934 MacRobertson Air Race. Three examples took part in the race and one of them won it. The type set many aviation records during the race and afterwards, as a pioneer mail plane. The modern features and clean lines of the DH.88, especially in the striking colours of Grosvenor House, the race winner, make it a true design classic.
- 1 Design and development
- 2 Operational history
- 3 Airworthy replicas
- 4 Operators
- 5 Specifications
- 6 In popular culture
- 7 See also
- 8 References
- 9 External links
Design and development
The MacRobertson International Air Race, a race between London and Melbourne to be held in October 1934 to celebrate the 100th anniversary of the State of Victoria, was announced in 1933. Despite previous British air racing successes, culminating in 1931 in the outright winning of the Schneider Trophy, there was no British aeroplane capable of putting up a challenge over the MacRobertson course with its long overland stages. In January 1934, the de Havilland company stepped into the breach when it offered to design a 200 mph (322 km/h) aircraft to compete in the race and produce a limited run if three were ordered by February 1934. The sale price of £5,000 each would by no means cover the development costs.
Three orders were indeed received, and de Havilland set to work. The airframe consisted of a wooden skeleton clad with spruce plywood, with a final fabric covering on the wings. A long streamlined nose held the main fuel tanks, with the low-set and fully glazed central two-seat cockpit faired into an unbroken line to the tail. The wings were of a thin cantilever monoplane design for high-speed flight, and as such would require stressed-skin construction to achieve sufficient strength. While other designers were turning to metal to provide this extra strength, de Havilland took the unusual approach of increasing the strength of all-wood construction. De Havilland achieved the skin profile using many thin, shaped pieces set side by side, and then overlaid in the manner of plywood. This was made possible only by the recent development of high-strength synthetic bonding resins and its success took many in the industry by surprise.
The engines were uprated versions of the standard Gipsy Six, being tuned for best performance with a higher compression ratio. The DH.88 could maintain altitude up to 4,000 ft (1,200 m) on one engine. The propellers were two-position variable pitch, manually set to fine before takeoff using a bicycle pump and changed automatically to coarse by a pressure sensor. The main undercarriage retracted upwards and backwards into the engine nacelles, while the tailskid did not retract. Later examples and rebuilds would feature a castoring tail wheel.
Landing flaps were placed slightly forward of the inboard wing trailing edge and continued in to the aircraft centre line. The forward fuselage was occupied by two large fuel tanks, with a third small tank located behind the cockpit.
With de Havilland managing to meet the challenging production schedule, testing of the DH.88 began six weeks before the start date of the race.
In 1935, de Havilland proposed a high-speed bomber version of the DH.88 to the RAF, but the proposal was rejected.
The DH.88 might have been the only wooden British high-performance monoplane, but for a shortage of metal for aircraft construction during the Second World War. Experience with the DH.88 would later be put to use in designing the DH.98 Mosquito, also a twin-engined monoplane of wooden construction. The Mosquito was not simply the 1935 proposal revisited but was a much bigger and more powerful aircraft powered by two Rolls-Royce Merlin engines delivering over twice the power of the Gipsy Sixes.
First to take off at 6.30 a.m. on 20 October were Jim and Amy Mollison in their own G-ACSP Black Magic. They made a faultless journey to Baghdad, and reached Karachi at around 10 a.m. on the second race day, setting a new England-India record. Problems began for the Mollisons when their landing gear failed to retract, and after returning Karachi for repairs, they were again delayed by an inability to navigate at night.
Further problems followed when they made an unscheduled refuelling stop at Jobbolpore but found no aviation fuel. Running instead on fuel used by the local bus company, an engine piston seized and an oil line ruptured. They flew on to Allahabad and retired.
The scarlet G-ACSS was the property of Mr A.O.Edwards and was named Grosvenor House after the hotel which he managed. The crew were C. W. A. Scott and Tom Campbell Black. When the Mollisons ran into problems at Karachi, Scott and Campbell Black took over the lead and were first into Allahabad. Despite a severe storm over the Bay of Bengal they reached Singapore safely, eight hours ahead of the DC-2.
They took off for Darwin, but over the Timor Sea lost power in the port engine when the oil pressure dropped to zero. Repairs at Darwin got them going again, although continuing oil warnings caused them to fly the last two legs with one engine throttled back. Their lead was unassailable despite this, and after the final mandatory stop and more engine work at Charleville they flew on to cross the finish line at Flemington Racecourse at 3.33 p.m. (local time) on 23 October. Their official time was 71 hours 18 seconds.
Records set by G-ACSS 'Grosvenor House'
|Date of Record||Record achieved|
|20-23 October 1934||C. W. A. Scott and Tom Campbell Black went from Mildenhall, England to Melbourne, Australia (11000 miles) in 70 hrs 55 min. Still held in 2010.|
|14-16 November 1937||A.E. Clouston and Mrs Kirby-Green went from London to Cape Town (7091 miles) in 45 hrs 6 min.|
|18-20 November 1937||The return trip was completed in 57 hrs 23 min.|
|15-20 March 1938||A.E. Clouston and V. Ricketts went from London to New Zealand (13179 miles) in 104 hrs 20 min.|
|20-26 March 1938||The return trip was completed in 140 hrs 12 min. Here the times to and from Sydney, Australia en route to New Zealand were also confirmed as records.|
The third Comet, G-ACSR had been paid for by racing driver Bernard Rubin and was flown by Owen Cathcart Jones and Ken Waller. They had to make a second unscheduled stop at Baghdad after they found that they had had a serious oil leak. They were forced to delay for repairs which were carried out by T.J.Holmes. They caught up with the Mollisons at Karachi. They were the fourth aircraft to reach Melbourne, in a time of 108 h 13 min 45 s. Cathcart Jones and Waller promptly collected film of the Australian stages of the race and set off to carry it back to Britain. Their return time of 13½ days set a new record.
Grosvenor House was taken charge of by the Air Ministry and flown to Martlesham Heath for evaluation. Repainted silver and given the military serial K-5084 it made several flights before being written off and sold for scrap after a heavy landing. It was subsequently sold on, rebuilt and fitted with Gypsy Six series II engines and a castoring tailwheel, in which form it made several race and record attempts under various names. It claimed fourth place in the 1937 Istres-Damascus-Paris race, and later the same year lowered the out-and-home record to the Cape to 15 days 17 hours. In March 1938, Arthur Edmond Clouston and Victor Anthony Ricketts made a return trip to New Zealand covering 26,450 mi (42,570 km) in 10 days 21 hours 22 minutes.
G-ACSR was renamed Reine Astrid and flew the Christmas mail from Brussels to Leopoldville in the Belgian Congo in 1934. It was then sold to the French government as F-ANPY and set a Croydon-Le Bourget record of 52 minutes on 5 July 1935. It subsequently made Paris–Casablanca and Paris—Algiers high-speed proving flights. F-ANPY was destroyed in a hangar fire, alongside F-ANPZ (see below), at Istres in France in June 1940.
Black Magic was sold to Portugal for a projected flight from Lisbon to Rio de Janeiro. Re-registered CS-AAJ and renamed Salazar it made various flights from London to Lisbon, setting a time of 5 hr, 17 min in July 1937. It was re-discovered in a ruinous condition in Portugal in 1979 and is currently undergoing restoration in Derby, England.
Following the French government's acquisition of F-ANPY (see above), they ordered a fourth Comet, F-ANPZ, with a mail compartment in the nose. Both were destroyed in a hangar fire at Istres in France in June 1940.
The fifth and last Comet, registered G-ADEF and named "Boomerang," was built for Cyril Nicholson. it was piloted by Tom Campbell Black (of Grosvenor House fame) and J.C. McArthur in an attempt on the London-Cape Town record. It reached Cairo in a record 11 hr, 18 min but the Cape Town attempt was abandoned due to oil trouble. G-ADEF crashed in Sudan on 22 September 1935, the crew escaping by parachute.
CS-AAJ has been rediscovered after being lost for more than 40 years in Portugal and is currently under restoration to its original identity as Black Magic, hopefully to flying condition, by the Comet Racer Project Group based at Derby Airfield in England.
An airworthy full-scale replica of the DH.88 Comet was built in 1993 by Thomas W. Wathen of Santa Barbara, California, USA. N88XD flies wearing the full colours and registration of G-ACSS Grosvenor House.
- Air Ministry for evaluation
Data from De Havilland Aircraft since 1909
- Crew: two
- Length: 29 ft 0 in (8.84 m)
- Wingspan: 44 ft 0 in (13.41 m)
- Height: 10 ft 0 (3.05 m)
- Wing area: 212.5 sq ft (19.75 m2)
- Airfoil: RAF 34
- Empty weight: 2,930 lb (1,332 kg)
- Loaded weight: 5,550 lb (2,523 kg)
- Powerplant: 2 × de Havilland Gipsy Six R six-cylinder air-cooled inverted inline engine, 230 hp (172 kW) each
- Maximum speed: 237 mph (206 kn, 382 km/h)
- Cruise speed: 220 mph (191 kn, 354 km/h)
- Stall speed: 74 mph (64 kn, 119 kn/h) 
- Range: 2,925 mi (2,541 nmi, 4,710 km)
- Service ceiling: 19,000 ft (5,790 m)
- Rate of climb: 900 ft/min (4.6 m/s)
In popular culture
In the Dutch aviation comics series "January Jones" the title heroine, a U.S. racing pilot in the 1930s, flies and owns a de Havilland DH.88, usually indicated as (De Havilland) Comet. Its red-with-white colour and #43 resemble Grosvenor House. This series has been published in Dutch, French, Danish, Norwegian, Finnish, Portuguese, Catalan, Spanish and German.
- Aircraft of comparable role, configuration and era
- Allaz and Skilbeck 1998, pp. 94–95.
- Lewis 1970, p. 257.
- Jackson 1987, p. 356.
- - 0246.html "The England–Australia Race". Flight, Vol. XXV, No. 1284, 3 August 1933, p.770.
- Ramsden Aeroplane Monthly May 1988, p. 279.
- Winter, H.T.; Flight today and tomorrow, 1st Edition, Blackie, ca. 1949, Page 232.
- "Forest Products Laboratory: The use of wood for aircraft in the United Kingdom." Madison, Wisconsin: United States Department of Agriculture Report No. 1540, 1942, p. 1.
- "Clouston's fine flight." Flight, 24 March 1938. Retrieved: 25 June 2012.
- "Highest, fastest, farthest ... Place-to-place records: Category 2 (Pilot and passengers)." Flight, 5 January 1950. Retrieved: 25 June 2012.
- "Black Magic DH88 1934." Comet Racer Project Group. Retrieved: 24 January 2011.
- Jackson 1987, pp. 360–361.
- Jackson 1987, p. 357.
- Taylor Air Enthusiast July–September 1979, p. 55.
- Allaz, Camille and John Skilbeck (translator). History of Air Cargo and Airmail from the 18th century. London: Christopher Foyle Publishing, 1998. ISBN 0-9548896-0-6.
- Jackson, A.J. De Havilland Aircraft since 1915. London: Putnam 1962.
- Jackson, A.J. De Havilland Aircraft since 1909. London: Putnam, Third edition, 1987. ISBN 0-85177-802-X.
- Lewis, Peter. British Racing and Record Breaking Aircraft. London: Putnam, 1970. ISBN 0-370-00067-6.
- Ramsden, J.M. "The Comet's Tale - Part 2". Aeroplane Monthly, Vol. 16 No. 5, May 1988. pp. 279–283. ISSN 0143-7240.
- Taylor, H.A. "The First "Wooden Wonder"", Air Enthusiast, Ten, July–September 1979. pp. 51–57.
|Wikimedia Commons has media related to De Havilland DH 88 Comet.|
- The MacRobertson Air Race, 1934
- "British Victor in Air Classics" Popular Mechanics, January 1935
- Comet DH88 - fastest from England to Australia
- Black Magic Restoration
- Tom Campbell Black Pioneer Aviator co winner of the MacRobertson Air Race 1934
- Walkaround photo gallery of Shuttleworth's Comet G-ACSS
- Sound recording of G-ACSS