There's no ignoring the elegance of the Trident's lines. The wings are set way back towards that soaring tail. The fuselage juts gracefully forward, tapering to a stepped cockpit windscreen. Free from engine clutter, the slim wings rake back, suggesting speed and - for the dawn of the sixties - leading-edge modernity. Yet the initial development of this beautiful aircraft was all but stifled by the very specification that created it. It's an interesting - and rather depressingly British - story.

The aircraft was de Havilland's response to a request by BEA. The state-owned carrier was highly conservative in its approach to technology, and it had proved highly resistant to the emergence of jet power in civil aviation. While the company had cautiously accepted oil-burners in the highly successful Vickers Viscount, it preferred its jet turbines to turn a propeller rather than push its aircraft along on a trail of hot gas. So when BEA requested a larger, faster, long-haul type, Vickers responded with the Vanguard - a superb and classic aircraft, but ultimately doomed by its turbo-prop engines.

Meanwhile, in France, Sud Aviation had developed the twin-jet Caravelle, which drew heavily on expertise supplied by de Havilland, the pioneers of passenger jet transport. The high speed and quietness of this neat, appealing 80-seater were impossible to ignore. But still BEA clung to the belief that profitable long-haul carriage required propellers. They continued with the Vanguard in this role, but bent slightly by drawing up a specification for a medium-haul, 70-seat jet airliner. Initially, de Havilland worked on designs for variants of the Comet, designated D.H.119 and 120. Then, in 1957, they submitted the D.H.121, a three-jet design with two engines mounted on the rear fuselage, similar to the Caravelle's design, and a third installed inside the rear fuselage. It would appear that de Havilland had foreseen the shortcomings of BEA's specification and, on adopting the new Rolls-Royce Medway turbofan engines, upped the passenger capacity to 98.

The DH121 would be the world's first three-jet airliner. BEA's specification had called for "more than two engines", so the new design certainly ticked that box, but de Havilland, with their customary clean-sheet approach, saw that four engines would reduce economy. The unique three-motor design gave the new aircraft its name: Trident.

Government pressure to rationalise the aviation industry led to de Havilland forming a consortium with Hunting and Fairey. The group adopted the name Airco, after the company for whom Geoffrey de Havilland designed aircraft during WW1. Believing that Boeing might be interested in building the D.H.121 under licence, Airco invited the American manufacturer to its Hatfield headquarters. However, Boeing had begun developing its own three-jet machine - the 727 - in 1959. Airco naively shared its research, contributing substantially to what would become its principal - and ultimately more successful - rival design.

BEA issued a letter of intent, committing to 24 D.H.121s, on 12 February 1958. This was followed by a government order in August, despite the administration's preference for Bristol's submission, the Type 200.

Airco, recognising the trend among airlines to provide more seating in economy class, further increased the payload of the Trident to 111.

Innovation extended beyond the novel engine arrangement. The Trident boasted advanced avionics that made it the first airliner capable of fully automatic ‘blind’ landing in reduced visibility, even in fog. This would be a real asset in the fog-plagued airports of Europe. The first automatic landing on a scheduled passenger service was performed on 10 June 1965 and the first genuinely ‘blind’ landing on 4 November 1966. Moving map displays had already begun to appear in aircraft cockpits, but again, the Trident advanced the breed. The Decca system in use in aircraft like the Comet was notoriously inaccurate, as its ground-transmitted signals were distorted by the curvature of the earth. The Trident used a ground-breaking doppler system to trace its position (which was still displayed on a rolling piece of paper - no computers here!). This was accurate enough that the aircraft could be navigate the Atlantic just by steering to keep the tracing pen on course.

Due to its aerodynamic shape and thin, clean wing, the Trident was a slippery beast, which contributed greatly to its performance and economy. But that low drag meant that it wasn't too keen on slowing down for descent. So de Havilland came up with another first: the reverse thrust system was modified to be used in the air. It was a highly effective solution, but one that occasionally brought yelps of surprise from rapidly decellerated passengers!

Trident looked set for success. It met or exceeded every specification requirement, and its 111 seat capacity made it a real load carrier. But BEA was concerned that growth in passenger numbers was slowing, and instructed de Havilland to downsize it. The manufacturer complied and the prototype Trident 1C first lifted off from Hatfield on 9 January 1962.

The new design was fast - very fast. Its thin wing, free of draggy engine pods, allowed it to cruise at over 980km/h (610mph). And low drag meant better economy, so the airlines were happy. There was, however, a downside. While superb at high speed, at low speed the wing generated less lift than other designs in use at the time. That meant long a take-off roll, leading to the Trident's nickname among aircrews. It's famed unwillingness to unstick led to it being known as "The Gripper".

Sadly, Trident was to become another British potential world-beating design to be crippled by poor decisions. BEA's instruction to reduce the aircraft's passenger capacity meant that other European airlines decided against buying the new type. A year later, Boeing introduced the 727, which had a similar capacity to the original Trident design. This excellent machine slotted pefectly into the gap left by the reduced Trident, and de Havilland's opportunity, through no fault of its own, was missed.

BEA, recanting their previous instruction, called for a larger Trident, giving rise to the Trident 2 and the later Trident 3. This last could even be classed as a four-engine, as an additional booster turbojet was fitted into the tail to provide extra take-off thrust.

Government pressure to rationalise the aviation industry caused further production delays as companies coalesced and reorganised. De Havilland ultimately became part of the new Hawker Siddeley composite. Baulked by delays and poor decisions, Trident would never fulfil the potential of its mould-breaking design. Ultimately, 115 Tridents were built, compared to 1,832 727s.

G-AVFB was the second of 15 Trident 2Es ordered by BEA. It made its first flight at Hatfield on 2 November 1967 and was delivered to Heathrow on 6 June 1968. In June 1973 it was sent on loan to Cyprus Airways and re-registered 5B-DAC. It was parked at Nicosia airport when Turkey invaded Northern Cyprus in 1974 and it suffered gunfire damage in the ensuing fighting. Afterwards it was abandoned on the airfield along with other damaged Tridents. Eventually British Airways sent some engineers to survey the Tridents to see if any of them could be repaired and then recovered to London, with a view to returning them to service. On inspection, our aircraft had sustained just some bullet holes in its fuselage. These were repaired with patches and it was ferried to Heathrow in May 1977 and restored to its original British registration. Following total refurbishment and repainting in BA livery, it was used on the airline’s inter-city shuttle services until its last service from London to Manchester on 27 March 1982. It was then donated to Duxford Aviation Society and flown to Duxford on 13 June 1982 after 21,642 flying hours and 11,726 landings. In 1990 it was repainted in its original BEA ‘Red Square’ livery and is now on permanent display as part of the British Airliner Collection.