AP 118 · No. 10 Section II · Aircraft Plate 165 / 295

Plate 165 of 295 · Early jet age · Tailless swept-wing research jet

de Havilland DH.108 Swallow

DH.108, VW120, painted as VW120, the third de Havilland DH.108, in 1948, when John Derry flew it to a 100 km closed-circuit speed record in April and past the speed of sound in a dive that September: a small tailless research jet with a Vampire-derived fuselage nacelle lengthened to a pointed nose, a low metal canopy with a flat-panelled windscreen and small oval side windows, wings swept at 45 degrees with leading-edge slats, elevons and small fins under the tips, wing-root intakes for its de Havilland Goblin 4 turbojet, a single swept fin and rudder and a tricycle undercarriage: high-speed silver overall, roundels above and below the wings, a red and blue fin flash, black ‘VW120’ on the rear fuselage and under the wings, and the yellow prototype ‘P’ in a ring ahead of the jet pipe, as photographed in 1948 (none of the three DH.108s survives; the shape was taken from published three-views of VW120 scaled to the published span and length, and checked against photographs; the race number it carried at the 1948 SBAC show is left off).

3D model

Turn it over

A procedural model built in Blender from published dimensions, drawings and photographs, painted as VW120, the third de Havilland DH.108, in 1948, when John Derry flew it to a 100 km closed-circuit speed record in April and past the speed of sound in a dive that September: a small tailless research jet with a Vampire-derived fuselage nacelle lengthened to a pointed nose, a low metal canopy with a flat-panelled windscreen and small oval side windows, wings swept at 45 degrees with leading-edge slats, elevons and small fins under the tips, wing-root intakes for its de Havilland Goblin 4 turbojet, a single swept fin and rudder and a tricycle undercarriage: high-speed silver overall, roundels above and below the wings, a red and blue fin flash, black ‘VW120’ on the rear fuselage and under the wings, and the yellow prototype ‘P’ in a ring ahead of the jet pipe, as photographed in 1948 (none of the three DH.108s survives; the shape was taken from published three-views of VW120 scaled to the published span and length, and checked against photographs; the race number it carried at the 1948 SBAC show is left off). Drag to orbit, scroll or pinch to zoom · download .glb (760 KB)

Data plate

Specification

First flight, number built and top speed are for the whole family (TG283, TG306, VW120); engine, crew and dimensions are for the DH.108, VW120 modelled here.

History

The DH.108

In 1945 de Havilland’s early designs for the Comet jet airliner had swept wings and no tailplane, and nobody yet knew how such an aircraft would handle. To find out, the company built a small research aircraft to Air Ministry specification E.18/45, designed by John Carver Meadows Frost: the fuselage nacelle and Goblin engine of a Vampire fighter, with a new wing swept back by more than 40 degrees, elevons in place of a tailplane and a single swept fin. Three were built. The first, TG283, was a low-speed aircraft with fixed slats, and first flew from RAF Woodbridge on 15 May 1946; the second, TG306, had a wing swept at 45 degrees for high-speed work and flew that June.

On 27 September 1946 Geoffrey de Havilland Jr, the company’s chief test pilot and son of its founder, took TG306 up to practise for an attempt on the world speed record. In a dive at about Mach 0.9 over the Thames Estuary the aircraft broke up, and he was killed. By then the Comet had been given a conventional tail, so the DH.108 became a pure research aircraft for swept wings at high speed. A third, VW120, was built with a longer, pointed nose, a lower canopy and a more powerful Goblin 4, and first flew on 24 July 1947.

In VW120 John Derry set a world speed record over a 100 km closed circuit on 12 April 1948, at about 605 mph, and on 6 September 1948 he took it past the speed of sound in a dive from 40,000 to 30,000 ft, the first time a British aircraft had done so. The DH.108 was never an easy aircraft: the test pilot Eric Brown called it a killer. VW120 crashed near Brickhill, Buckinghamshire, on 15 February 1950, killing Squadron Leader Stuart Muller-Rowland, and TG283 was lost at Hartley Wintney on 1 May 1950 during stall and spin tests, killing Squadron Leader George Genders. None of the three survives; the Ministry of Supply named the type Swallow, but de Havilland never used the name.

This airframe

DH.108 VW120

VW120The airframe modelled

VW120 was the third and last DH.108, built for high-speed research with a lengthened, pointed nose, a low canopy over a lowered seat and a Goblin 4 engine. It was first flown by John Cunningham on 24 July 1947, set the 100 km closed-circuit record with John Derry in April 1948 and took him past the speed of sound that September, and was lost with Stuart Muller-Rowland in February 1950. No DH.108 survives, so the model shows the one that drawings and photographs record best: a published three-view of VW120 itself and some fifteen photographs of it, two of them in colour. The model shows it as they do in 1948: high-speed silver overall, roundels above and below the wings, a red and blue fin flash with no white band, black ‘VW120’ on the rear fuselage and under the wings, and the yellow prototype ‘P’ in a ring ahead of the jet pipe. Its shape was taken from the three-view scaled to the published span and length and checked against the photographs, which also gave the shape of the intakes and canopy. The published height is unreliable, so the model’s height comes from the drawing. The race number it carried at the 1948 SBAC show, seen in only one photograph, is left off, as are the small stencils.

Where to see one

Not on charge

All three DH.108s crashed between 1946 and 1950, killing their pilots, so none survives in any museum.

All 295 plates

Profiles and models are procedural interpretations built in Blender from published dimensions, three-view drawings and photographs of each airframe. Treat the museum aircraft as the reference.