De Havilland DH.88 Comet

de Havilland Aircraft Company

Industry	Aircraft manufacturing
Founded	1920
Founder	Geoffrey de Havilland
Headquarters	Hatfield , United Kingdom
Products	Aircraft, including the DH.88 Comet

This article is about aircraft from the 1930s designed for racing. For the jet-powered airliner, see de Havilland Comet.

The de Havilland DH.88 Comet is a British twin-engine, two-seat airplane constructed by the de Havilland Aircraft Company. It was purpose-built to compete in the 1934 England-Australia MacRobertson Air Race, which spanned from the United Kingdom to Australia.

Conceived as both a prestige endeavor and a demonstration of cutting-edge methods, the Comet was tailored specifically to satisfy the race’s demands. It marked the first British design to integrate all key features of contemporary high-speed aircraft into a single airframe—this included stressed-skin construction, cantilever monoplane wings, retractable landing gear, flaps, variable-pitch propellers, and an enclosed cockpit.

A total of three Comets were completed for the race, each commissioned by private owners and offered at a reduced price of £5,000 per unit. The development timeline was notably brief, with the initial flight occurring merely six weeks before the competition. The aircraft G-ACSS Grosvenor House ultimately secured victory in the race. Subsequently, two additional Comets were manufactured post-race. These aircraft set numerous aviation records during and after the event and participated in further competitions. Several national governments acquired three units for evaluation, often utilizing them as mail planes. Of these, two—G-ACSS and G-ACSP—remain extant, and multiple full-scale replicas have been constructed.

Context: The Great Air Race

In 1933, plans were underway for the MacRobertson Air Race—a staged flight from Britain to Australia scheduled for October 1934—to commemorate the centenary of Victoria in Australia. Sponsored by Australian confectioner Macpherson Robertson, this event involved flying in segments from England to Melbourne.

At that time, American manufacturers were advancing a new generation of monoplane airliners unmatched by British designs, prompting Geoffrey de Havilland—a pioneering British aviator and founder of de Havilland Aircraft Company—to resolve that Britain should present a formidable contender for national honor. Although company executives understood that recovering the full costs of such an aircraft was unlikely, they anticipated that undertaking this project would boost corporate prestige and provide valuable experience in developing fast monoplanes.

Consequently, in January 1934, de Havilland declared that if three orders were secured by 28 February, they would construct a specialized racing aircraft named the Comet, guaranteeing a minimum speed of 200 miles per hour (320 km/h) and pricing each at £5,000. This figure represented approximately half the production cost. By the deadline, three orders had been placed: one from Jim Mollison for himself and his wife Amy (also known as Amy Johnson), another from hotelier Arthur Edwards, and a third from racing driver Bernard Rubin.

Design phase

Although the Comet was created specifically to meet the unique demands of the MacRobertson race, its unconventional specifications meant it did not conform to the typical standards for racing aircraft. Despite this, it was categorized under "Special, sub-division (f), Racing or Record". De Havilland focused heavily on ensuring the aircraft had the extended non-stop range required for the lengthy official legs of the race. Their original concept involved developing a twin-engine, two-seat variant of the DH.71 experimental monoplane. However, this design lacked sufficient performance, prompting designer A. E. Hagg to pursue a more advanced approach. The final concept was a cantilever monoplane featuring an enclosed cockpit, retractable undercarriage, and flaps. To achieve a reasonable takeoff speed despite a high overall weight and maintain an efficient high-speed cruise, fitting variable-pitch propellers was essential.

File:Gipsy Six R.jpg

One of the original race-tuned Gipsy Six R engines installed on the victorious DH.88 Comet Grosvenor House, preserved at the Shuttleworth Collection.

The finalized design incorporated a low, tapered wing with a high aspect ratio and was powered by two Gipsy Six R engines—an enhanced version of the new Gipsy Six. The airframe was predominantly wooden, with metal used sparingly for high-stress elements such as engine mounts and undercarriage, as well as for complex curved components like engine cowlings and wing root fairings. The metal parts employed a lightweight magnesium-aluminium alloy. Manually operated split flaps were installed beneath the inboard rear sections of the wings and lower fuselage, while the Frise ailerons were balanced using lead strips embedded in their leading edges. Both the rudder and elevators on the conventional tail featured horn mass balances. To verify the wing’s structural integrity, a half-scale wing model was constructed and subjected to destructive testing. The aircraft’s exterior received meticulous treatment involving repeated cycles of painting and sanding to create an exceptionally smooth finish that minimized aerodynamic drag and enhanced speed.

Emphasizing aerodynamic refinement, designers opted for a thin wing with a RAF34 airfoil section. This thin profile was insufficient to house spars deep enough to bear flight loads independently; therefore, most of the load was carried by the wing skin itself through a "stressed-skin" structural approach. The complex aerodynamic curves could not be formed from plywood alone. Drawing on his background as a naval architect, Hagg adapted a technique previously employed in lifeboat construction. The majority of the wing surface was covered with two layers of 2 in (51 mm) wide diagonal spruce planking; the outer layer was laid crosswise over the inner layer. These planks varied in thickness based on load requirements, tapering from 0.5 in (13 mm) at the root to 0.14 in (3.6 mm) near the tip. The wing was assembled as a single unit around three box spars positioned at 21%, 40%, and 65% chordwise locations, with spruce stringers placed between spars to prevent buckling. Birch plywood and spruce composed the ribs. Due to difficulties in machining spruce planks thinner than 0.07 in, outboard sections measuring 6 ft (1.8 m) were covered with various thicknesses of plywood instead. The leading edge ahead of the front spar also featured plywood covering. The center section received reinforcement via two extra layers of 0.07 in (1.8mm) spruce. This construction method was made feasible only by recent advances in high-strength synthetic adhesives and took many industry experts by surprise.

File:Comet Cockpit.jpg

Cockpit of G-ACSS Grosvenor House (2010), significantly altered from its original configuration.

The fuselage primarily consisted of plywood stretched over spruce longerons, while compound curves on the upper and lower forward sections were formed using spruce planking layers. Like the wings, structural strength relied heavily on skin integrity. Fuel was stored in three fuselage tanks: two main tanks located in the nose and center section ahead of the cockpit, plus an auxiliary tank holding just 20 gallons positioned immediately behind the cockpit to assist with trim adjustments. The pilot and navigator sat in tandem within a cockpit situated aft of the wing; although dual flight controls were installed, only the front seat contained a complete instrument panel. The rear crew member could view many instruments by leaning sideways while seated. To minimize drag, the cockpit was positioned low; however, this compromised forward visibility significantly. The engines were upgraded versions of de Havilland’s newly developed Gipsy Six, optimized for racing with increased compression ratios and reduced frontal area; this allowed single-engine operation up to approximately 4,000 feet (1,200 m) altitude. The main undercarriage retracted rearward into engine nacelles and was manually operated via a large handwheel on the right side of the cockpit requiring fourteen full turns.Template:Page needed

Due to tight production deadlines, flight testing commenced only six weeks before race day. Initially equipped with Hamilton-Standard hydromatic variable-pitch propellers, testing revealed that propeller blade roots disrupted airflow into the engines excessively. Consequently, these were replaced with French two-position pneumatically actuated Ratier propellers whose blades were manually set to fine pitch pre-takeoff using a bicycle pump; during flight they automatically shifted to coarse pitch via a pressure sensor for high-speed cruising. A limitation was that fine pitch could only be reset on the ground. Additional modifications included fitting a large landing light in the nose and raising the cockpit profile slightly to improve pilot visibility.

MacRobertson Race

The trio of Comet aircraft assembled at Mildenhall, a recently developed airfield in Suffolk soon to be transferred to the RAF, ready for the race start. G-ACSP was finished in black and carried the name Black Magic, G-ACSR appeared in green without a name, and G-ACSS was painted red and called Grosvenor House. These three joined 17 other competitors, which included modern fast Douglas DC-2 and Boeing 247 airliners as well as older Fairey Fox biplanes.

G-ACSP Black Magic

Among the Comets, only G-ACSP was piloted by its owner. Jim Mollison, accompanied by his wife Amy, took off first, departing at 6:30 a.m. with the aircraft named Black Magic. Their initial leg was a nonstop flight to the first compulsory stop at Baghdad, making them the sole crew to complete this segment without landing. From there, they proceeded to Karachi, arriving at 4:53 a.m., setting a new record for travel time between England and India. After two failed departure attempts—first due to a landing gear retraction issue, then because they realized they had an incorrect map—they finally departed Karachi at 9:05 p.m. heading for Allahabad. Having drifted off course, they made an unplanned stop at Jabalpur to refuel and fix their position. With no aviation fuel available locally, they resorted to motor car petrol supplied by a bus company; this caused one piston to seize and ruptured an oil line. They managed to continue to Allahabad on a single engine but required complete engine replacements and were ultimately forced to withdraw from the race.

G-ACSS Grosvenor House

File:DeHavilland DH.88 Comet, "Grosvenor House" G-ACSS, in Martin Place, Sydney 12 November 1934..jpg

Grosvenor House in Martin Place, Sydney, Australia, 12 November 1934.

The red Comet G-ACSS was named after the Grosvenor House Hotel by its managing director, Arthur Octavius Edwards. He selected C. W. A. Scott and Tom Campbell Black as pilots for the competition.

After refueling at Kirkuk, Scott and Campbell Black reached Baghdad after the Mollisons had departed but resumed their flight following a brief half-hour stop. Skipping Karachi entirely, they flew nonstop to Allahabad where they were informed they had arrived first, having overtaken the Mollisons. Despite encountering a violent storm over the Bay of Bengal, requiring both pilots to jointly manage the controls, they safely landed in Singapore, arriving eight hours ahead of the DC-2.

Their next leg took them toward Darwin, during which they experienced power loss in the port engine over the Timor Sea but persevered until reaching Darwin. While mechanics addressed engine repairs, its designer, Frank Halford, noticed a news bulletin from England and contacted Darwin by phone. After discussing the situation, he advised that despite warning signals, continuing flight at reduced power was feasible. Although delayed by this issue, their lead was secure. Following the final compulsory stop and additional engine maintenance at Charleville, they proceeded to finish at Flemington Racecourse at 3:33 p.m. local time on 23 October. Their official completion time was recorded as 70 hours 54 minutes 18 seconds.

G-ACSR

The third Comet, registered as G-ACSR, was coated in British racing green by Bernard Rubin, a distinguished motor racing driver. Rubin had planned to pilot the aircraft himself alongside Ken Waller, but due to sudden illness, he withdrew at the last moment and appointed Owen Cathcart Jones as his replacement.

Upon reaching Baghdad, the crew inadvertently overshot their destination during nighttime and landed near a village when fuel levels became critically low. They departed at dawn and managed to arrive in Baghdad with nearly empty tanks. However, after takeoff, a significant oil leak forced them to return for repairs. Additional complications arose on the leg to Darwin, leading them to land at Batavia. Template:Cnspan G-ACSR was the fourth plane to arrive in Melbourne, completing the journey in 108 hours 13 minutes 30 seconds. Immediately after arrival, Cathcart Jones and Waller collected footage of the Australian segments of the competition and departed the following day to return it to Britain. Their return flight established a new record for the round trip to Australia, finishing in 13 days 6 hours 43 minutes.

After the race

File:IWM-MH5416-Comet-205127918.jpg

The race-winning aircraft (formerly G-ACSS), re-registered as K5084 and painted in RAF colours, 1936

File:DH88-2290.jpg

G-ACSS later known as The Orphan, preparing for an air race in 1937 – Flight photograph.

Following the event, Grosvenor House was dismantled and transported back to England. Subsequently acquired by the Air Ministry, it received the military serial K5084, was painted silver with RAF insignia, and flown to RAF Martlesham Heath for testing by the Aeroplane and Armament Experimental Establishment. After several flights, it suffered a heavy landing that led to it being written off and sold for scrap. Later on, it was purchased again, rebuilt by Essex Aero, equipped with Gipsy Six series II engines and fitted with a castoring tailwheel. In this updated configuration, it participated in numerous races and record attempts under different names. It achieved fourth place in the 1937 Istres-Damascus-Paris race and ranked twelfth in that year’s King's Cup. During the same year, it also set a new out-and-home record to Cape Town with a time of 5 days 17 hours. In March 1938, A. E. Clouston and Victor Ricketts completed a round trip to New Zealand, covering 26,450 mi (42,570 km) within 10 days 21 hours 22 minutes.

The day following their race completion, Cathcart Jones and Waller departed from G-ACSR for their return trip. While experiencing engine problems at Allahabad, they encountered the Mollisons still present there; generously, they received two good pistons from Black Magic enabling them to proceed. Upon returning to England, they had established a new round-trip record of 13 days, 6 hours and 43 minutes. That December, renamed Reine Astrid in tribute to the Belgian queen, G-ACSR carried Christmas mail from Brussels to Leopoldville in the Belgian Congo.Template:Page needed Later sold to the French government and converted into mail plane F-ANPY, its delivery flight set a record between Croydon and Le Bourget on July 5, 1935. It also conducted high-speed proving flights between Paris–Casablanca and Paris—Algiers bearing the name Cité d'Angoulême IV. Previously thought destroyed alongside F-ANPZ, F-ANPY was last observed grounded at Étampes in France by 1940.

Black Magic was sold to Portugal with plans for a Lisbon-to-Rio de Janeiro flight. Re-registered as CS-AAJ and renamed Salazar, it suffered damage during an attempted takeoff at Sintra Air Base for its Atlantic crossing. On a subsequent return journey from Hatfield, it set a London-to-Lisbon record time of five hours seventeen minutes in July 1937.

Additional Comets

After the French government purchased the F-ANPY model (as mentioned earlier), they commissioned a fourth Comet, designated F-ANPZ, which featured a mail compartment located in the nose section. This aircraft was subsequently incorporated into the French Air Force fleet but was lost in a hangar fire at Istres in France during June 1940.

The final, fifth Comet bore the registration G-ADEF and carried the name Boomerang. Constructed for Cyril Nicholson, it was flown by Tom Campbell Black and J. C. McArthur during an attempt to break the London-Cape Town speed record. The aircraft achieved a record-setting time of 11 hours and 18 minutes to reach Cairo, but an oil-related issue forced an early end to the subsequent flight segment over Sudan. On 21 September 1935, Campbell Black and McArthur launched another Cape record attempt from Hatfield in "Boomerang." Unfortunately, the plane crashed over Sudan on 22 September 1935 due to propeller malfunction, though both crew members survived by parachuting to safety.

Record Flights

Throughout the 1930s, de Havilland Comets established numerous long-distance speed records, both in competitive races and dedicated record-breaking attempts. Several flights achieved multiple point-to-point records along their routes.

15–20 March 1938|| G-ACSS|| A.E. Clouston and Victor Ricketts|| London–New Zealand|| 13,179 miles (21,210 km)|| data-sort-value=6260 |104 hr 20 min|| Named Australian Anniversary 20–26 March 1938|| G-ACSS|| A.E. Clouston and Victor Ricketts|| New Zealand–London|| 13,179 miles (21,210 km)|| data-sort-value=8412 |140 hr 12 min|| Return leg completing first round trip

Record flights by DH.88 Comets

Date	Aircraft	Crew	Route	Distance	Time	Notes
20–21 October 1934	G-ACSP	Jim Mollison and Amy Mollison	England–Karachi			Participated in the MacRobertson air race
20–23 October 1934	G-ACSS	C. W. A. Scott and Tom Campbell Black	England–Australia	11,000 mi (18,000 km)	70 hr 55 min	Winner of the MacRobertson air race
20 Oct–2 Nov 1934	G-ACSR	Owen Cathcart Jones and Ken Waller	England–Australia–England	22,000 mi (35,000 km)	13 days 6 hr 43 min	First segment during the MacRobertson air race
20 December 1934	G-ACSR	Ken Waller and Maurice Franchhomme	Brussels–Belgian Congo–Brussels	882 mi (1,419 km)	44 hr 40 min	Intermediate records established en route
26 February 1935	CS-AAJ	Carlos Bleck and Costa Macedo	London–Lisbon	1,010 mi (1,630 km)	6 hr 30 min
11 April 1935	F-ANPY	Hugh Buckingham and Martin Sharp	Croydon–Le Bourget	205 mi (330 km)	56 min	Known as Cité d'Angoulême IV
5 July 1935	F-ANPZ	Hubert Broad	Croydon–Le Bourget	205 mi (330 km)	50 min
1–2 August 1935	F-ANPY	Jean Mermoz and Léo Gimié	Paris–Casablanca–Dakar	2,990 mi (4,810 km)	15 hr 41 min	Return leg completed faster
September 1935	F-ANPY	Jean Mermoz and Léo Gimié	Paris–Algiers		8 hr 38 min
July 1937	CS-AAJ	Costa Macedo	London–Lisbon	1,010 miles (1,630 km)	5 hr 27 min	Surpassed previous record
14–16 November 1937	G-ACSS	A.E. Clouston and Betty Kirby-Green	London–Cape Town	7,200 miles (11,600 km)	45 hr 2 min	Named The Burberry
18–20 November 1937	G-ACSS	A.E. Clouston and Betty Kirby-Green	Cape Town–London	7,200 miles (11,600 km)	57 hr 23 min	Return journey

Surviving aircraft

File:DH88 Comet G-ACSS Grosvenor House (6741273695).jpg

G-ACSS Grosvenor House in 2011

In 1943, G-ACSS was once again conscripted for RAF service before being transferred to de Havilland. It underwent restoration to serve as a static exhibit named Grosvenor House and was displayed during the 1951 Festival of Britain. The Shuttleworth Collection at Old Warden took ownership in 1965, and by 1972 it was re-registered with its initial designation to facilitate restoration for flight, which was successfully completed in 1987. This aircraft is recognized as one of the most important British planes still operational.

File:DH.88 "Black Magic" under-restoration.jpg

G-ACSP Black Magic, undergoing restoration in 2016

After being missing for over four decades, CS-AAJ Salazar was found in Portugal and subsequently returned to the United Kingdom, where it regained its original registration as G-ACSP. Restoration efforts have been ongoing as of 2020 by the Comet Racer Project Group at the Amy Johnson Comet Restoration Centre located at Derby Airfield. The goal is to restore G-ACSP to flying condition, preserving its original Black Magic paint scheme.

Airworthy reproductions and replicas

N88XD represents a full-scale flying replica of the Comet, constructed in 1993 by Bill Turner of Repeat Aircraft at Flabob Airport in Rubidoux, California for Thomas W. Wathen from Santa Barbara, CA. It features the distinctive livery of G-ACSS Grosvenor House.

A replica initially begun by George Lemay in Canada was later acquired by the Croydon Aircraft Company, situated at Old Mandeville Airfield near Gore, New Zealand, where it remains under constructionTemplate:When.

The reproduction known as G-RCSR is being built based on original blueprints by Ken Fern alongside the ongoing restoration of Black Magic at Derby.

Operators

Template:FRA

• Armée de l'Air

Template:POR

• Government of Portugal

Template:UK

• Air Ministry (used for evaluation purposes)
• Shuttleworth Collection

Specifications

File:De Havilland DH.88 Comet 3-view NACA-AC-197.png

Three-view illustration of the de Havilland DH.88 Comet

Cultural influence

File:Hatfield, The Comet hotel - geograph.org.uk - 209701.jpg

The Comet Hotel located in Hatfield

File:CC09 DH Comet.jpg

A cigarette card depicting G-ACSS Grosvenor House

The MacRobertson Air Race held global significance and played a pivotal role in advancing aircraft engineering. The success of the Comet and its innovative high-speed design represented a key development in aviation history.

Constructed a year before the race, the Comet Hotel in Hatfield was among England’s earliest examples of modernist hotel architecture. Situated near the de Havilland manufacturing plant, it was named after the Comet Racer upon completion. Renowned war artist Eric Kennington was commissioned to sculpt a carved column approximately 9 feet (2.7 m) tall for its parking area, which was installed in 1936. Atop this column rests a celebrated model of the Comet, presentlyTemplate:When painted in the colors of Grosvenor House.

Life-sized but non-operational replicas of both Grosvenor House and Black Magic were produced for the 1990 Australian two-part television drama Half a World Away, also distributed on DVD as The Great Air Race. The replica of G-ACSS was capable of taxiing and has since been restored to represent G-ACSR; it is currently exhibited statically at the De Havilland Aircraft Museum, Salisbury Hall, UK.

The DH.88 Comet has also featured in various fictional works; see Aircraft in fiction#de Havilland DH.88 Comet for further details.

Notes

Bibliography

• "Regarding the England to Australia Air Race: The de Havilland 'Comet'", Flight, Vol. 26, No. 1343, 20 September 1934, pp. 968–972.
• Jackson, A. J. De Havilland Aircraft Since 1909. London: Putnam, 3rd edition, 1987. ISBN 0-85177-802-X.
• Lewis, Peter. British Racing and Record Breaking Aircraft. London: Putnam, 1970. ISBN 0-370-00067-6.
• Ogilvy, David. DH88: deHavilland's Racing Comets. Shrewsbury: Airlife, 1988. ISBN 1-85310-011-0.
• Ramsden, J. M. "The Comet's Tale – Part 2". Aeroplane Monthly, Vol. 16, No. 5, May 1988, pp. 279–283. ISSN 0143-7240.
• Ricco, Philippe. "La Comète en France, Part 1", Aeroplane, Vol. 35, No. 439, November 2009, pp. 20–25. Template:ISSN.
• Ricco, Philippe. "La Comète en France, Part 2: The Burden of Proof". Aeroplane Monthly, Vol. 38, No. 449, September 2010, pp. 30–34. Template:ISSN.
• Sharp, C. Martin; DH: An Outline of de Havilland History. London: Faber & Faber, 1960.
• Taylor, H. A. "The First 'Wooden Wonder'". Air Enthusiast, No. 10, July–September 1979, pp. 51–57. Template:ISSN
• "The Story of the Australia Race", Flight, Vol. 26, No. 1348, 25 October 1934, pp. 1110–1117.

External links

• Audio recording of G-ACSS, Aircraft Sound Recordings.
• Footage showing G-ACSS arriving in Australia