The Comet 4 was a further improvement on the stretched Comet 3 with even greater fuel capacity. The design had progressed significantly from the original Comet 1, growing by 18 ft 6 in (5.64 m) and typically seating 74 to 81 passengers compared to the Comet 1's 36 to 44 (119 passengers could be accommodated in a special charter seating package ...

The Comet 4 was a completely new aeroplane: one with over 50,000 hours of test and operational flying and a programme of scientific proving and ground testing which was unprecedented in aviation history, behind it – 80%, of which had been completed, with the Mk.3. Comet 4 simply had to be the safest aeroplane ever to fly.

The de Havilland Comet 4 was developed from the world’s first successful jet airliner, the de Havilland DH 106 Comet 1. The Comet 1 went into service with BOAC on 2 May 1952 and showed every sign of being a major success.

Many regard the DH106 Comet 3 as the most attractive in appearance of all the DH106 Comets, although trials indicated that it lacked the range required for North Atlantic operations. Further modifications were introduced to generate the DH106 Comet 4, the main production variant utilised by BOAC.

The Comet 4 (including 4B/4C) was the most successful. 77 were built, twice as many as all the other series put together, and they flew a total of 1.7 million hours. It was in commercial service from October 1958 to November 1980, and XS-235 continued to fly for the MoD until 1997.

BEA De Havilland DH-106 Comet 4B. credit: credits... Want More of This? We'll send you our latest and best content straight to your inbox.

The Comet was redesigned as the Comet 4 and flew again in 1958. This aircraft became the first to offer a scheduled Trans-Atlantic service and 113 were made before production ceased in 1968. De Havilland learned the harsh lessons of fatigue crack growth and passed these on to other aircraft manufacturers.

A Comet 4 struck trees on each of two approaches to the runway. The collisions resulted in damage to the flaps and, with the consequent loss of drag because of the damage, resulted in a too fast an approach on the final attempt at landing.

In service the Comet proved to be a remarkably tough and forgiving aeroplane. New equipment on the Mk.4 included the Smiths Flight System, cloud-and-collision warning radar, V.O.R. and new power loss indicators which only required monitoring during takeoff.

The Museum's Comet is the first Comet 4C, and took its first flight on October 31, 1959. It became the first jet airliner for Mexicana Airlines, registered as XA-NAR, serving routes between Mexico City and Los Angeles until 1970 and accumulating 27,065 flight hours.