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de Havilland DH.106 Comet

United Kingdom (1952)
National Flag Graphic
Origin: United Kingdom
Year: 1952
Type: Narrow-Body Passenger Airliner Aircraft
Manufacturer(s): de Havilland Aircraft Company - UK
Production: 114
Status: Retired, Out-of-Service


The worlds first jet-powered passenger airline, the de havilland DH.106 Comets reign was short-lived for the program suffered major setbacks by way of accidents and fatalities.


Detailing the development and operational history of the de Havilland DH.106 Comet Narrow-Body Passenger Airliner Aircraft.  Entry last updated on 5/17/2018. Authored by Staff Writer. Content ©www.MilitaryFactory.com

The de Havilland DH.106 "Comet" holds the distinction of becoming the world's first commercial marketplace passenger jet airliner. The design originated from work begun during World War 2 (1939-1945) in 1943 looking to the future of British passenger air travel. Including prototypes used in the flight-testing phase of the program, a total of 114 Comets were completed with primary customers being BOAC, British European Airways, Dan-Air, and the Royal Air Force (RAF). The last example was retired on March 14th, 1997. A first-flight, in prototype form, was recorded on July 27th, 1949.

The Comet enjoyed a period of early success and high-level publicity, giving the British a head start in the jet-driven, passenger-hauling marketplace but the series was done-in by equally high-profile crashes and accidents. This period eventually allowed competitors in the United States to take-over with their own storied designs. For the British, the Comet did influence another major Cold War player, the Hawker Siddeley "Nimrod" (detailed elsewhere on this site) of the late-1960s as forty-nine of these were built for the RAF to a maritime patrol standard..

Comet Development
During the Comet's design study phase, several forms of the what would become the DH.106 emerged including a version with twin tail booms, one with canard foreplanes, and another lacking horizontal tailplanes altogether while relying on a wide-area, swept-back wing mainplane. Many of these early offerings were influenced by "blank canvas" thinking in the late-World War 2 period as it revolved around the prospect of jet-powered flight. As the decade wore on, however, the Comet's design began to materialize along more traditional lines - giving us the tried-and-true jet airliner form still in play today.

Comet Walk-Around
A tubular fuselage was envisioned to act as the center point of the aircraft in which a short nosecone gave pilots excellent vision over the frontal section. The passenger section then took up most of the internal volume of the tube which tapered at the aft-end to form the empennage. The tail unit consisted of a single, rounded vertical tail fin complemented by low-set horizontal planes. The wing mainplanes were also set low, this at about midships, and featuring sweepback of the leading wing edges. Within each wingroot was buried paired turbojet engines, aspirated through ports at the wing leading edges and exhausting through ports beyond the trailing edges. Their position within the wing allowed the aircraft to retain considerable aerodynamic efficiency by basic streamlining. For ground-running, multi-wheeled landing gear members were used which were wholly retractable.

Comet Variants
There were four notable series variants in the Comet line named simply as "Comet 1", "Comet 2", "Comet 3, and "Comet 4". The original 40-seat Comet 1 emerged in production through a dozen airframes and were detailed with square windows, the overall appearance based heavily on the original de Havilland prototype. However, by this time, the design had incorporated multi-bogie main landing gear members over the original's single-wheeled forms. Original models were fielded with 4 x Ghost 50 Mk 1 series turbojet engines but these later gave way to 4 x Ghost FGT3 series engines.

From this initial model arrived the Comet 1A which increased performance allowing for greater take-off weights, speed, and range. Ten examples followed to the standard. The Royal Canadian Air Force (RCAF) was the recipient of a pair of Comet 1 models and these were taken on with reinforced skins and operated under the Comet 1X name. The follow-up Comet 1XB standard was nothing more than the Comet 1A with a strengthened fuselage understructure and more rounded windows.

The Comet 1 series enjoyed a maximum speed of 460 miles per hour with an MTOW of 110,000lb, a range out to 1,500 miles, and a cruising altitude of 42,000 feet. With these specifications, it clearly outpaced prop-driven developments of the period - garnering much interest from a public thirsty for flight.

The Comet 2 was given modified wing mainplanes which incorporated greater surface area and switched to more powerful Rolls-Royce "Avon" turbojets to better handle proposed cross-Atlantic / overwater routes. This also increased operational ranges but not to the extent required for such travel. The variant was some three feet longer than the original Comet 1 and was also differentiated by having the rounded windows of the later Comet 1 marks. The initial Comet 2 went airborne for the first time on August 27th, 1953 and deliveries followed in 1955. Variants went on to include the one-off Comet 2X development model (with its RR Avon 502 turbojets), a pair of Comet 2E aircraft (with mixed RR Avon 504/Avon 524 turbojet parings), a pair of Comet T2 marks (to serve the RAF as crew trainers), eight RAF-bound Comet 2C platforms, and a trio of Comet 2R developmental-minded platforms.
Both the Comet 1 and Comet 2 marks could be equipped to carry 36 and 44 passengers. Maximum speed for the Comet 2 was 490 miles per hour with an MTOW of 120,000lb, a range out to 2,600 miles, and a cruising altitude of 42,000 feet.

The Comet 3, first appearing in 1954, was the next logical offshoot of the series. It was over 15 feet longer than the earlier Comet 2 and was completed with 4 x RR Avon M502 turbojet engines of greater power. This, naturally, led the mark to exhibit better range and overall performance when compared to previous Comet marks but only two Comet 3 airframes were built. These went on to live largely developmental lives for their part in the Comet story and nine additional airframes went unfinished. Reduced-span wing mainplanes were used in the related Comet 3B and this model was flown publically at Farnborough 1958.

The Comet 3 was arranged to carry between 58 and 76 passengers. Maximum speed was 520 miles per hour with an MTOW of 150,000lb, a range out to 2,700 miles, and a cruising altitude of 45,000 feet.

The Comet 4 continued the development avenue of the Comet 3 series and increased fuel capacity even more, leading to better operational ranges, and there were improvements to performance, take-off weight, and internal seating capacity as well. First-deliveries of the mark, with reduced wingspans and a longer fuselage, began in September of 1958 with eighteen examples going to carrier BOAC. A further twenty-three, produced under the Comet 4C designation, were given the wing of the Comet 4 standard with the fuselage of the Comet 4B. A pair of prototypes were forged from the Comet 4C work and these served the all-important Hawker Siddeley "Nimrod" project detailed elsewhere on this site.

The Comet 4 held the capacity to carry 56 to 81 passengers. Maximum speed was 520 miles per hour with an MTOW of 156,000lb, a range out to 3,225 miles, and a cruising altitude of 42,000 feet miles.

The Comet 5 mark was a proposed, improved form of the Comet line and set to include a wider fuselage for additional seating, a revised wing mainplane with greater sweepback, and more efficient Rolls-Royce "Conway" turbofan engines held in wing nacelles/pods. This design fell to naught.

The Comet Bomber
Back in 1946, the British Air Ministry drew up Specification B.35/46 calling for a nuclear-capable, high-altitude reconnaissance platform and the DH.106 was briefly considered in the DH.111 "Comet Bomber" guise. The design emerged in 1948 but the effort was dropped in favor of the V-Bomber force which took control of the British nuclear arsenal for the foreseeable future.

Operators and Service Career
Operators of the Comet were global and ranged from Argentina and Australia to Sudan and the United Kingdom. The British, as well as the Canadians, operated the platform at the military level as well which put the airframe through the rigors of defense-minded service during the Cold War period (1947-1991). In the former, the Comet C2, Comet 2R, and the Comet C4 were all the marks used from a period spanning 1956 until 1975. In the latter, the Comet 1A was the choice mount though the aircraft fleet were later upgraded to the Comet 1XB standard. The RCAF operated its Comets from 1953 until 1963.

Operation of the Comet was marred by accidents and fatalities numbering thirteen crashes and 426 lives lost. From the period of May 1953 until April of 1954, there were three high-profile crashes alone which force the entire fleet to be grounded pending review. This period was then used to enact revisions to the design and it was not until 1958 that the series was allowed back into the air. The lull in operations allowed American competitors in Boeing and Douglas time to centralize their efforts and leap ahead of the British in the jet-powered passenger market.




General Assessment (BETA)
Firepower  
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Performance  
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Survivability  
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Versatility  
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Impact  
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Rating: 52 (of 100)
The rating is an internal assessment derived from forty factors pertaining to this entry.
Relative Maximum Speed Rating
Hi: 500mph
Lo: 250mph
    This entry's maximum listed speed (466mph).

    Graph average of 375 miles-per-hour.
City-to-City Ranges
NYC
 
  LON
LON
 
  PAR
PAR
 
  BER
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  MOS
MOS
 
  TOK
TOK
 
  SYD
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  LAX
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  NYC
Graph showcases the de Havilland Comet 1's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
114
114


  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.


Altitude Visualization
Small airplane graphic
  Compare this entry against other aircraft using our Comparison Tool  
Global Operators:
Argentina; Australia; Canada; Ceylon (Sri Lanka); Ecuador; Egypt; France; Greece; Kenya; Kuwait; Lebanon; Malaysia; Mexico; Portugal; Saudi Arabia; Singapore; South Africa; Sudan; Tanzania; Uganda; United Kingdom
Historical Commitments / Honors:

Military lapel ribbon for Operation Allied Force
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of Britain
Military lapel ribbon for the Battle of Midway
Military lapel ribbon for the Berlin Airlift
Military lapel ribbon for the Chaco War
Military lapel ribbon for the Cold War
Military lapel ribbon for the Cuban Missile Crisis
Military lapel ribbon for the Falklands War
Military lapel ribbon for the French-Indochina War
Military lapel ribbon for the Golden Age of Flight
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Iran-Iraq War
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1982 Lebanon War
Military lapel ribbon for the Malayan Emergency
Military lapel ribbon for the attack on Pearl Harbor
Military lapel ribbon for the Six Day War
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Suez Crisis
Military lapel ribbon for the Vietnam War
Military lapel ribbon for Warsaw Pact of the Cold War-era
Military lapel ribbon for the WASP (WW2)
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.
Measurements and Weights icon
Structural - Crew, Dimensions, and Weights:
Unless otherwise noted the presented statistics below pertain to the de Havilland Comet 1 model. Common measurements, and their respective conversions, are shown when possible.

Operational
CREW


Personnel
4


Dimension
LENGTH


Feet
91.86 ft


Meters
28 m


Dimension
WIDTH


Feet
114.83 ft


Meters
35 m


Dimension
HEIGHT


Feet
29.53 ft


Meters
9 m


Weight
LOADED


Pounds
110,231 lb


Kilograms
50,000 kg

Engine icon
Installed Power - Standard Day Performance:
4 x Halford H.2 Ghost 50 turbojet engines developing 5,000 lb of thrust each (paired in wing roots).

Performance
SPEED


Miles-per-Hour
466 mph


Kilometers-per-Hour
750 kph


Knots
405 kts


Performance
RANGE


Miles
1,491 mi


Kilometers
2,400 km


Nautical Miles
1,296 nm


Performance
CEILING


Feet
42,651 ft


Meters
13,000 m


Miles
8.08 mi

Armament - Hardpoints (0):

None.
Variants: Series Model Variants
• Comet - Base Series Name
• Comet 1 - Initial production model; squared window ports; 4 x Ghost 50 Mk 1 turbojet engines; 40 passenger seating.
• Comet 1A - Increased weight operations with greater range; water-ethanol injection introduced for engines; ten examples completed.
• Comet 1X - Pair for RCAF operation; reinforced skins.
• Comet 1XB - Four Comet 1A models brought up to the Comet 1XB standard; rounded windows.
• Comet 2 - Second major series model
• Comet 2X - One-off model with 4 x Rolls-Royce Avon 502 turbojets; developmental variant.
• Comet 2E - Pair of Comet 2 aircraft with mixed Avon 504 /524 engines.
• Comet T2 - RAF crew trainers based on Comet 2.
• Comet C2 - RAF aircraft
• Comet 2R - Three aircraft used for RAF radar/electronics development.
• Comet 3 - Third, limited series model
• Comet 3B - Reduced-span wings
• Comet 4 - Definitive production form; improved Comet 3; increased fuel capacity with greater passenger seating, increased MTOW, and better overall performance; Avon turbojet engines.
• Comet 4B - Capital Airlines model; reduced wingspan and greater internal capacity by way of lengthened fuselage.
• Comet 4C - Comet 4 wing assemblies with Comet 4B lengthened fuselage.
• Comet 5 - Proposed version with wider fuselage and revised wings of greater sweepback; to be powered by Rolls-Royce Conway series jet engines in podded nacelles; not built.
• DH.111 "Comet Bomber" - Designed for Air Ministry Specification B35/46; not built.
• Type HS.801 ("Maritime Comet") - Prototypes serving the Hawker Nimrod program for maritime patrol platform in the Royal Air Force.