De Havilland Comet: The airliner that changed aviation forever

On Sir Geoffrey de Havilland’s 67th birthday in 1949, the aircraft that propelled the world into the jet age took to the skies for the first time. Key Aero examines the history of the revolutionary DH.106 Comet 

Shortly after the conclusion of the Second World War, the UK government formed the Brabazon Committee, which was tasked with examining the country’s future airliner needs.

Key Collection
The de Havilland Comet was the world's first commercial jetliner. Key Collection

One of its main recommendations was for the development of a pressurised, transatlantic mail-carrying aircraft that could fly a one-ton payload at cruising speeds close to 400mph. 

Alistair Hodgson, the curator of the de Havilland Aircraft Museum at the time of recording explains what it was like to fly on the Comet in this video. 

Aerospace firm de Havilland was keen to fulfil this requirement but chose to challenge the widely held view at the time that jet engines were too unreliable and fuel-hungry for such a role.  

The committee accepted the firm’s proposal, dubbing it the “Type IV” and awarded a development and production contract to de Havilland under the designation Type 106 in February 1945. 

 

Design and Development 

The type was so advanced that de Havilland had to take on the design and development of both the airframe and engines. This was because, at the time, no turbojet engine manufacturer could offer an engine capable of producing the required thrust and fuel consumption for flight at the proposed cruising altitude of 40,000ft. 

Engines
The Comet's four Rolls-Royce Avon turbojet engines were buried within the wing roots. Key Collection

A design team was formed in 1946 under the leadership of Ronald Bishop – who had been responsible for the Mosquito fighter-bomber. Several non-standard configurations were considered such as canards and tailless designs – all were eventually dismissed. 

Comet Production
The de Havilland Comet production line at the company's Hatfield facility. Key Collection

With no time to develop the technology needed for a tailless design, Bishop focused the team’s efforts on a more conventional 20-degree swept-wing shape with unswept horizontal stabiliser surfaces. 

Replacing previously specified de Havilland-built Halford H.1 Goblin engines, four new, more powerful Rolls-Royce Avons were integrated in pairs submerged in the wing roots. 

 

Prototypes and First Flights 

The first prototype, G-ALVG (c/n 6001) was completed in 1949 and was initially used to conduct ground tests and brief early flights. The jet’s maiden flight, out of Hatfield Aerodrome took place on July 27, 1949. Lasting 31 minutes – the company’s chief test pilot John Cunningham was at the controls. 

Comet
G-ALVG was the first prototype for the Comet. Key Collection

The second example, G-ALZK (c/n 6002) was completed in July 1950 and was used by the BOAC Comet Unit from April 1951 to carry out 500 hours of crew training and route proving ahead of its service introduction.

Comet
The first prototype DH.106 Comet (carrying Class B markings G-5-1) was completed in 1949. Key Collection

Australian flag carrier Qantas also send across its own technical experts to observe the performance of the prototypes, seeking to put to bed internal uncertainty about its first jet purchase. 

 

Comet Crashes 

Following its introduction into service with BOAC on May 2, 1952, the Comet was subsequently involved in five incidents in the first two years of use – four of which were fatal.  

The first hull loss occurred on October 26, 1952, when a BOAC flight departing Rome’s Ciampino airport failed to become airborne and ran into the rough ground at the end of the runway. Two passengers sustained minor injuries, but the aircraft G-ALYZ (c/n 6012) was written off. 

Alistair Hodgson, the curator of the de Havilland Aircraft Museum, explains the cause of the two crashes in this video.

The second incident occurred on March 3, 1953, when a Canadian Pacific Airlines Comet 1A, CF-CUN (c/n 6014) failed to become airborne while attempting a take-off in Karachi, Pakistan. The aircraft impacted a dry drainage canal embankment, killing all five crew and six passengers on board. 

The Comet’s third crash – and second fatal incident – occurred on May 2, 1953, when BOAC Flight 783, G-ALYV (c/n 6008) crashed in a severe thundersquall six minutes after taking off from Calcutta, killing all 43 onboard. 

The two Comet crashes of 1954 were a pivotal moment for the type which led to its grounding lasting nearly four years.

 

Return to Service 

On April 27, 1958, the Comet 4 flew for the first time. Gone were the square windows and thin aircraft skin, instead, de Havilland had implemented all the recommended changes and improved the fuel capacity on the new variant. 

Comet 4
The Comet 4 received its certificate of airwortiness on September 24, 1958. Key Collection

The first example was delivered to BOAC on September 25, 1958, the day after it received its certificate of airworthiness. The Comet 4 allowed the airline to inaugurate the first regular jet-powered transatlantic services on October 4, 1958, between London and New York.  

During its 16-year production run, 114 airframes were produced. The narrowbody airliner will always hold the title of the “World’s first commercial jetliner” and its creation marked the start of the jet-age, a period in aviation that continues to this day.