De Havilland DH.106 Comet

Updated: October 2026 – A slim, silvery silhouette, a slightly swept wing and not a single engine nacelle underneath: on the De Havilland DH.106 Comet, the four jet engines are buried in the wing, right next to the fuselage. In 1952 it was the first jet airliner in airline service, and it changed aviation twice – first with its success, then with a series of accidents whose investigation is still built into every pressurized fuselage today. You won’t see it fly anymore, but you can see it in several museums, one of them in Germany. Here’s how to recognize it, what sets the versions apart and how it became the Nimrod maritime patrol aircraft.

What is the De Havilland Comet?

The Comet is a four-engine jet airliner from the British manufacturer de Havilland of Hatfield, north of London. It was built as a low-wing aircraft with a pressurized cabin, swept wing and nose gear. Its most striking feature: the engines don’t hang in nacelles under the wing but are built into the wing roots in pairs. This gave an aerodynamically clean line but made maintenance and later engine changes more laborious.

The first production version, the Comet 1, seated 36 to 44 passengers and flew at around 740 km/h – roughly twice as fast as the propeller aircraft of its day, and at high altitude above the weather. It was powered by four de Havilland Ghosts, an in-house jet engine. The later versions got more powerful Avon engines from Rolls-Royce.

Including the prototypes, 114 Comets were built. That sounds like few compared with Boeing’s later successes. But the Comet was the aircraft from which the whole industry learned what jet service means. Before that, de Havilland had become known mainly for light aircraft like the Tiger Moth and the wartime Mosquito.

From prototype to the first jet airline service

The idea of a jet airliner arose in Britain during World War II. A government committee under Lord Brabazon sketched out several aircraft types for the postwar period, including a fast jet-powered mail plane for the routes to the Empire. De Havilland turned it into a passenger aircraft.

On July 27, 1949, the prototype with the registration G-ALVG took off at Hatfield. At the controls was test pilot John Cunningham, who had become known as a night fighter pilot in the war. The first flight lasted about half an hour. Intensive testing and record flights followed, drawing attention around the world.

On May 2, 1952, the Comet G-ALYP of the British Overseas Airways Corporation (BOAC) took off from London on the world’s first scheduled jet passenger flight, bound for Johannesburg with several stopovers. For passengers, the difference was enormous: less vibration, less noise in the cabin, much shorter travel times. Soon afterward, Air France and the French UAT also flew the Comet 1A. How the type thrilled the public is told in more detail in the article De Havilland Comet: the first jetliner.

The accident series and its investigation

The lead did not last long. Within two years, several Comets were lost, and the causes were puzzling at first.

Date	Registration	Location	What happened
October 26, 1952	G-ALYZ (BOAC)	Rome-Ciampino	Failed to lift off on takeoff, hull loss, no fatalities
March 3, 1953	CF-CUN (Canadian Pacific)	Karachi	Failed to lift off on a night takeoff, all 11 on board killed
May 2, 1953	G-ALYV (BOAC)	near Calcutta	Crashed shortly after takeoff in a thunderstorm, all 43 on board killed
January 10, 1954	G-ALYP (BOAC)	Mediterranean off Elba	In-flight break-up, all 35 on board killed
April 8, 1954	G-ALYY (for South African Airways)	Mediterranean near Naples	In-flight break-up, all 21 on board killed

The two takeoff accidents were attributed to the handling when the nose was raised too far; de Havilland subsequently changed the wing leading edge. The crash near Calcutta was explained by extreme loads in the thunderstorm. After the accident off Elba, the fleet was briefly grounded and cleared again in March 1954 – only a few weeks before G-ALYY crashed near Naples. After that, the Comet 1 lost its certification.

What followed is regarded as a milestone of accident investigation. The Royal Navy recovered large parts of G-ALYP from the sea off Elba. At the Royal Aircraft Establishment in Farnborough, the fuselage of the Comet G-ALYU was placed in a water tank and the cabin was pressurized again and again to simulate thousands of flights. After a good 3,000 cycles, the fuselage tore open at a cutout near an emergency exit. On G-ALYP, the investigators found the starting point at a rivet hole at the window for a navigation antenna on the fuselage roof.

The lesson: metal fatigue from the constant pressure changes had been underestimated. Stresses concentrate at the corners of cutouts, and that’s where cracks grow. The findings fed into the design of all later pressurized fuselages – including those of competitors. The often-repeated line “the square windows were to blame” falls short, however; the investigation report did not see the shape of the passenger windows as the cause. Part of G-ALYP’s fuselage roof is now on display at the Science Museum in London.

Comet 2, 3 and 4: the second attempt

De Havilland didn’t give up. The already-built Comet 2 with Avon engines received a strengthened structure and went not to airlines but to the Royal Air Force, which used it as a transport and in an electronic reconnaissance version until the mid-1970s. The stretched Comet 3 remained a one-off and served as a test aircraft for the Comet 4.

The Comet 4 first flew on April 27, 1958. It was longer, heavier, faster and had a much greater range. On October 4, 1958, BOAC used it to open the transatlantic jet service between London and New York – a few weeks before Pan Am followed with the Boeing 707-120. In the end, though, the race for the market was won by Boeing and the Douglas DC-8, which were bigger and more economical. You can read how the 707 shaped the jet age in the history of the Boeing 707.

Version	Feature	Passengers	Engine
Comet 1 / 1A	First production version, square windows	36–44	de Havilland Ghost
Comet 2	Strengthened, stretched, to the RAF	–	Rolls-Royce Avon
Comet 3	Single test aircraft for the Comet 4	–	Rolls-Royce Avon
Comet 4	Long-haul version for BOAC	typically 74–81	Rolls-Royce Avon 524
Comet 4B	Longer fuselage, shorter wing, 18 built	up to 99	Rolls-Royce Avon
Comet 4C	Long fuselage of the 4B with the wing of the Comet 4, 28 built	up to 119 in charter layout	Rolls-Royce Avon

Besides BOAC, the Comet 4 flew with Aerolíneas Argentinas and East African Airways. The 4B was intended for the European routes of British European Airways and also flew with Olympic Airways. The 4C found customers in Mexicana, Kuwait Airways, Middle East Airlines, Misrair – the predecessor of EgyptAir – and Sudan Airways. Their colors are among the classics of the early jet era; more on that in the article Legendary airline liveries.

Dan-Air and the end of airline service

When the big airlines switched to larger jets in the 1960s, many Comets moved into charter service. The British Dan-Air collected used aircraft of all versions and so became the largest Comet operator of all – depending on the count with 48 or 49 aircraft, some of them only as spare parts donors.

On November 9, 1980, Dan-Air flew a special flight for aviation fans from London Gatwick with the Comet 4C G-BDIW. It is regarded as the last commercial Comet flight. The type stayed active longer in military use and as a test platform: the Comet 4C XS235 “Canopus” served British research establishments and landed for the last time on March 14, 1997. No Comet has flown since.

The Nimrod: the Comet in military service

The best-known development carries a different name. When the Royal Air Force was looking for a successor to its maritime patrol aircraft in the 1960s, Hawker Siddeley – by then the parent company of de Havilland – proposed a converted Comet 4C. The first two prototypes were built from unfinished Comet 4C airframes, with the first flight on May 23, 1967.

The Nimrod looks clearly different on the outside: beneath the fuselage sits a second, bulging lower fuselage for the weapons bay and equipment, so the cross-section looks like a figure eight. At the tail of the anti-submarine versions, a long boom with a magnetic anomaly detector sticks out to the rear, and instead of Avons, four Rolls-Royce Spey turbofans work in the wing roots. The Comet’s wing layout was retained.

• Nimrod MR1/MR2: maritime patrol aircraft for submarine hunting and search and rescue support, in RAF service from October 1969; the MR2 was retired on March 31, 2010.
• Nimrod R1: three aircraft for electronic reconnaissance, recognizable by the missing tail boom; last flight in June 2011.
• Nimrod AEW3: airborne early warning version with distinctive radar domes at the nose and tail, canceled in 1986.
• Nimrod MRA4: largely newly built version from BAE Systems, canceled in 2010 before it entered service.

A heavy blow was the crash of Nimrod XV230 on September 2, 2006 near Kandahar in Afghanistan, in which all 14 service members on board died. XV230 had, of all aircraft, been the first Nimrod delivered to the RAF, in 1969. How to recognize maritime patrol aircraft and similar special-mission aircraft today is shown in the article Recognizing AWACS, maritime patrol and reconnaissance aircraft.

How to recognize the Comet

In a museum, the Comet often stands among other classics of the 1950s and 1960s. Four looks let you place it with confidence.

You can also recognize the Comet 4 and 4C by the elongated extra tanks sitting at the front of the wings. As always, the registration gives the exact version; for British aircraft, the guide to British G- registrations helps you look up the history.

Comet, Tu-104, Nimrod or Trident?

Several types of this era look similar at first glance. The finder helps narrow it down.

The Tupolev Tu-104 followed the same design principle with engines in the wing root. The Hawker Siddeley Trident and the Vickers VC10 belong to the next British jet generation with tail-mounted engines, as does the French Caravelle – whose nose, incidentally, is based on Comet design parts. You’ll find an overview of vintage aircraft in the guide Recognizing historic aircraft.

Where to see the Comet and the Nimrod today

No Comet flies anymore, but several museums preserve well-kept examples. The list shows the best known.

Museum	Example	Note
Flugausstellung Hermeskeil (aviation exhibition)	Comet 4C G-BDIW	Dan-Air colors, aircraft of the last commercial Comet flight, ex RAF XR398
Imperial War Museum Duxford	Comet 4 G-APDB	One of the BOAC aircraft from the time of the transatlantic launch
RAF Museum Cosford	Comet 1XB G-APAS, Nimrod R1 XV249	Only fully preserved Comet 1
National Museum of Flight East Fortune	Comet 4C G-BDIX	Near Edinburgh
de Havilland Aircraft Museum	Comet 1A fuselage F-BGNX	Early square windows
Museum of Flight Seattle	Comet 4C N888WA	At the museum’s restoration center near Everett

For fans from Germany, Austria and Switzerland, Hermeskeil is the obvious address: that’s where the very aircraft stands with which Dan-Air put the final full stop on commercial Comet operations in 1980. A tour is worthwhile in Great Britain; Duxford combines well with an air show day, more on that in the article Airshows at Duxford. You can also find a Nimrod R1 at the East Midlands Aeropark right at the airport – there you can combine a museum visit with spotting. More Nimrods stand in several British collections.

Photo tips for the Comet in a museum

Photographing a Comet outdoors or in a hall is a different task from spotting at the fence. A few points help.

Outside at Hermeskeil or Duxford, the result depends heavily on the light – you can work out in advance when the sun is favorable with the sun position planner in Planetrack. Afterward, you post your Comet with type, registration and location so other spotters know what condition it is currently in.

Conclusion

The De Havilland Comet is one of the most important aircraft in aviation history. In 1952 it showed that jet service works, and two years later it painfully showed where the limits of the knowledge of the time lay. The whole industry drew lessons from the investigation that are still built into every pressurized fuselage today. The Comet 4 brought the type back, and the Nimrod kept its legacy in the air until 2011. Why other design principles ultimately prevailed is also examined in the article on the end of the four-engine jets.