The de Havilland Aircraft Company DH.106 Comet 3 (G-ANLO) flew for the first time on 19th July 1954, and was in reality an extensively developed aircraft, derived from the earlier DH.106 Comet 1 and 2. Fuselage length was increased by 15 feet 5 inches to provide accommodation for up to 58 passengers (although this was further increased with the introduction of the DH.106 Comet 4) plus the addition of wing pinion fuel tanks which were introduced to provide extended range capability.
Many regard the DH.106 Comet 3 as the most attractive in appearance of all the DH.106 Comets, although trials indicated that it lacked the range required for North Atlantic operations. Further modifications were introduced which resulted in the DH.106 Comet 4, the main production variant utilised by British Overseas Airways Corporation (BOAC). The DH.106 Comet 4 had the required performance for non-stop services from London to New York, this service being inaugurated on 4th October 1958.
In addition to the BOAC fleet, export sales were also made to Aerolineas Argentinas (6 aircraft) and East African Airways (3 aircraft).
However, the need for a higher capacity aircraft was identified by Capital Airlines in the USA (although their order was subsequently cancelled). The aircraft that duly emerged was the DH.106 Comet 4B, which was specifically for British European Airways (BEA) operations. This variant was readily distinguished by its longer fuselage section (118 ft compared with 111 ft 6 in) and the lack of the wing pinion fuel tanks. 18 were built in total: 14 for BEA and 4 for Olympic Airways.
The final version, the DH.106 Comet 4C, combined the fuselage of the DH.106 Comet 4B, with the wings of the DH.106 Comet 4, to produce a long fuselage variant with pinion tanks. The DH.106 Comet 4C was notably successful in the export market with sales to Misrair, Mexicana, Aerolineas Argentinas, Sudan Airways, Kuwait Airways and Middle East Airlines.