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In-Depth – De Havilland DH-88 Comet

May 7, 2010 2 comments

Hi! Welcome to this new category of this blog. Here, i’ll go in-depth on several interesting models, always looking to focus on the less common ones but surely attractive either from a history, flight characteristics, peculiarity, difficulty, style, appearance or symbolism perspective. In most cases, i’m sure a bit of all of these will apply.

To start it off in a nice way, i’ll talk about one of my all-time favorite aircrafts. Don’t ask me why, but the Comet really stands out from every other plane when i compare it with others. It’s style, unique appearance, flight challenge and twin low engine just adds to the pack!

De Havilland DH-88 Comet
De Havilland DH-88 Comet

Specs

  • Crew – 2
  • Propulsion – 1 piston engine
  • Engine model – de Havilland Gipsy Six R
  • Engine power – 172 kW / 230 H.P.
  • Max speed – 206 kts / 237 mph / 382 km/h
  • Cruise speed – 191 kts / 220 mph / 322 km/h
  • Service ceiling – 19.000 ft / 5.791 m
  • Rate of climb – 1200 ft/min / 366 m/min
  • Range – 2.542 NM / 2.925 mi / 4.708 km
  • Empty weight – 2.840 lbs / 1.288 kg
  • Max takeoff weight – 5.320 lbs / 2.413 kg
  • Wingspan – 44,0 ft / 13,41 m
  • Wing area – 212 sq ft / 19,7 sq m
  • Length – 29,0 ft / 8,84 m
  • Height – 10,0 ft / 3,05 m
  • First flight – 08.09.1934
  • Total production – 5 units

History

The de Havilland DH-88 Comet was a twin-engined British aircraft that won the 1934 MacRobertson Air Race, a challenge for which it was specifically designed. It set many aviation records during the race and afterwards as a pioneer mail plane.

Despite previous British air racing successes, culminating in 1931 in the outright win of the Schneider Trophy, there was no British plane capable of putting up a challenge over the MacPherson course with its long overland stages. The de Havilland company stepped into the breach by offering to produce a limited run of 200 mph (322 km/h) racers if three were ordered by February 1934. The sale price of £5,000 each would by no means cover the development costs. In 1935, de Havilland suggested a high-speed bomber version of the DH-88 to the RAF, but the suggestion was rejected. (De Havilland later developed the de Havilland Mosquito along similar lines as the DH-88 for the high-speed bomber role.)

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 central two-seat cockpit forming an unbroken line to the tail. The engines were essentially the standard Gipsy Six used on the Express and Dragon Rapide passenger planes, tuned for best performance with a higher compression ratio. The propellers were two-position variable pitch, manually set to fine before takeoff and changed automatically to coarse by a pressure sensor. The main undercarriage retracted upwards and backwards into the engine nacelles. The DH-88 could maintain altitude up to 4,000 ft (1,200 m) on one engine.

De Havillands managed to meet their challenging schedule and testing of the DH-88 began six weeks before the start date of the race. On the day of the race, the three distinctively coloured planes took their places among 17 other entrants ranging from a new Douglas DC-2 airliner to two converted Fairey Fox bombers.

The first of the aircraft to fly was registered G-ACSP, named “Black Magic” and was bought by Jim and Amy Mollison (nee Johnson) who were both independently recognised as world record holders in their own right. This combination started the race as favorite. The “Black Magic” was the first of a great new generation of British aircraft that flew with all three of the now commonplace technical features: retractable undercarriage, variable pitch propellors and flaps.

De Havilland DH-88 Comet "Black Magic"
De Havilland DH-88 Comet “Black Magic”

The three Comets were painted in distinctive colours – the Mollisons’ G-ACSP Black Magic was black and gold; Bernard Rubins’ nameless G-ACSR was green and flown by Owen Cathcart Jones and Ken Waller; while G-ACSS, flown by C.W.A. Scott and Tom Campbell Black, was resplendent in red and white and named Grosvenor House.

G-ACSP "Black Magic", the first of the Comets, flown  by Jim and Amy Mollison
G-ACSP “Black Magic”, the first of the Comets, flown by Jim and Amy Mollison
G-ACSR - the green one - landing in Baghdad on its  way to Australia
G-ACSR – the green one – landing in Baghdad on its way to Australia
G-ACSS "Grosvenor House", winner  of the MacRobertson Trophy
G-ACSS “Grosvenor House”, winner of the MacRobertson Trophy

Grosvenor House

“Grosvenor House” went to Martlesham for RAF trials in 1935 and, painted all white as K5084, was a memorable feature of the 1936 Hendon display. It was subsequently damaged when landing with a full load and disposed of as scrap. F.E.Tasker then acquired it and Essex Aero Ltd rebuilt it at Gravesend with Gypsy Six series II engines driving DH variable pitch airscrews. In pale blue and renamed The Orphan, G-ACSS was flown into fourth place in the 1937 Marseilles-Damascus-Paris race by Flg Off A.F Clouston and George Nelson.

Bearing a third name, “The Burberry”, the aircraft left Croydon on November 14th 1937 piloted by Clouston and Mrs Kirby Green, who succeeded in lowering the out-and-home record to the Cape to 15 days 17 hours. Carrying its final name, Australian Anniversary, it left Gravesend on February 6th 1938, but broke no records after the undercarriage collapsed in Cyprus. The last historic flight by ‘SS was one of its greatest. Flown by Clouston and Victor Ricketts, it took off from Gravesend on March 15th 1938, reached Sydney in 80 hours 56 minutes, crossed the Tasman Sea to Blenheim, New Zealand, in 7½ hours, stopped overnight, then returned to Croydon on March 26th. The 26,450 miles had been covered in 10 days 21 hours 22 minutes to set a record which still stands. The Comet then returned to Gravesend where it remained under tarpaulins until rediscovered in 1951. The DH Technical School then restored it to its original MacRobertson condition for display at the Festival of Britain Exhibition, after which it was preserved by the makers at Leavesden until handed over to the Shuttleworth Trust in 1965.

Flights and Records

On December 20th G-ACSR, suitably renamed Reine Astrid, left Evere, Brussels, piloted by Ken Waller and Maurice Franchomme, to carry the Christmas mail to Leopoldville in the Congo, arriving back on December 28th. It was then sold to the French government as F-ANPY and lowered the Croydon-Le Bourget record to 52 minutes during delivery by Hubert Broad on July 5th 1935. In the course of experimental work for a projected South Atlantic mail service, Jean Mermoz made Paris-Casablanca and Paris-Algiers high-speed proving flights in this machine in the following August and September.

A fourth Comet, registered as F-ANPZ, was built for the French government with a mail compartment in the nose. In their experiments with high-speed aircraft providing a mail service to far-flung colonies, the French also produced the Caudron C641 Typhon, an aeroplane that bore an uncanny resemblance to the Comet.

The Portuguese government had similar mail-carrying ideas, and acquired the Mollisons’ Black Magic for a projected flight from Lisbon to Rio de Janeiro. Renamed Salazar and re-registered as CS-AAJ, it was ferried from Hatfield to Lisbon on February 25th 1935 by Senor Carlos Bleck and Lt Costa Macedo, who covered the 1,010 miles nonstop in six hours five minutes. A return trip was made in the following September, and in 1937 Macedo again brought the aircraft back to Hatfield for overhaul; he made an outstanding return flight to Lisbon in five hours 17 minutes in July of that year. Shortly after being sold to Portugal, the “Black Magic” disappeared for a number of decades until it was found languishing on a portuguese farm and recovered to the UK. After passing through a number of owners, “Black Magic” now resides in a safe and secure environment with her own workshop. G-ACSP “Black Magic” is now in the process of a complete restoration to airworthy condition by the Comet Racer Project Group. Although a number of years away she will one day make her second “maiden” flight from the safety of her new home at Derby Airfield.

The last Comet

A fifth and final Comet named “Boomerang” was built to the order of Cyril Nicholson, who planned a series of attempts on the major long-distance records. Piloted by Tom Campbell Black and J.C.McArthur it made a record Hatfield-Cairo non-stop flight of 2,240 miles in 11 hours 18 minutes on August 8th 1935 during the first stage of an attempt on the Cape record. This was abandoned because of oil trouble, and the machine returned non-stop in 12 hours 15 minutes and established a new out-and-home record to Cairo. Although entered in the round-Britain King’s Cup Race of September 7th 1935, “Boomerang” was a non-starter and left a fortnight later for a second attempt on the Cape record; airscrew trouble over the Sudan on September 22nd compelled the crew to abandon the aircraft by parachute.

Radio Control Scale versions

To spice up your apetite, here’s an amazing 1/4th scale (3.35m wingspan!) radio controlled DH-88 Comet flight video. This awesome scale version can be powered up by two O.S. 160-200 size engines (2 or 4 stroke) for an amazing realism. Enjoy!

[to be continued… check back later]
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