Jet Comet G-ALVG, a.k.a ‘Blue Streak’, was de Havilland’s entry into the King’s Cup air race of 1950. Referred to in parts of the aviation media as the ‘dH.107’ (a designation never denied by de Havilland), it was more accurately the de Havilland T.K.7, designed and built by students of the de Havilland Technical School. The Jet Comet was an exercise in merging new or emerging technology into a single airframe, and the first jet design undertaken by the de Havilland Technical School.
The students’ task was to design an all-metal, single-seat race aircraft, applying modern construction techniques. Unsurprisingly, inspiration was readily found in the Hatfield-designed dH.88 Comet, upon which the fuselage (albeit for a single pilot) was based. Jet powerplant was a must, and the Halford/de Havilland Goblin was in plentiful supply. With the Goblin having first flown on 5 March 1943 on fifth prototype Meteor DG206, Goblins and modified Meteor engine nacelles were a must. The wings and the tailplane were based upon the design applied to the Messerschmitt Me 262, captured examples of which jad been extensively evaluated by the RAE after the war.
The jet Comet first flew in late 1949. Following low key testing it was entered into the 1950 Kings Cup air race. The overall blue colour scheme was chosen simply because none of the dh.88 Comets were so finished. All of the 88’s were named, and so G-ALVG was christened ‘Blue Streak’.
Sadly G-ALVG never flew in the race, having suffered an undercarriage collapse upon landing at Pendeford airfield the day before the race began. No one was hurt.
Footnote: the real first Comet jet (i.e. dH.106 Comet) was registered G-ALVG. ‘Blue Streak’ was of course the name of the de Havilland Propellers medium-range ballistic missile project, and later the first stage of the Europa satellite launch vehicle (
https://en.wikipedia.org/wiki/Blue_Streak_(missile)).

