de Havilland DH 108

DH 108 "Swallow"
The first DH 108 built – TG283. The torpedo-shaped objects on the wingtips are containers for anti-spin parachutes.
Role	experimental Type of aircraft
Manufacturer	de Havilland
Designer	John Frost
First flight	15 May 1946
Introduction	Experimental programme only
Status	Cancelled
Primary user	Royal Aircraft Establishment
Produced	1946–1947
Number built	3

The de Havilland DH 108 "Swallow" was a British

Design and development

Employing the main fuselage section and engine of the de Havilland Vampire mated to a longer fuselage with a single fin and swept wings, the de Havilland DH 108 was proposed in 1944 as an aerodynamic test bed for tailless designs, particularly the DH.106 Comet which had initially been considered a tailless, swept-wing concept.^[1] Despite the Comet design taking on more conventional features, the value of testing the unique configuration to provide basic data for the DH.110^[2] spurred de Havilland to continue development of the DH 108. Selecting two airframes from the English Electric Vampire F 1 production line, the new aircraft had unmistakable similarities to its fighter origins, especially in the original forward fuselage which retained the nose, cockpit and other components of the Vampire. The Ministry of Supply named the DH 108 the "Swallow", a name that was never officially adopted by the company.^[3]

The new metal wing incorporating a 43˚ sweepback was approximately 15% greater in area than the standard Vampire wing.^[2] Control was based on the conventional rudder in combination with elevons that were part elevator and ailerons, fitted outboard of the split trailing edge flaps.^[2] Although the Vampire fuselage was retained, as development continued, a revised nose and streamlined, reinforced canopy were incorporated.^[4]

Testing

The first DH 108

After the loss of the second prototype, a third aircraft was ordered to continue high-speed trials. VW120 became the third and final prototype. It differed from the first test aircraft in having an more streamlined pointed nose and smaller reinforced canopy (lowering the pilot's seat allowed for a more aerodynamic canopy shape to be employed), with the cockpit redesign allowing an

In 2001, a search at the crash site by a local using a metal detector was successful. He found some of the mounting bolts "cone shaped" that were removed when the remains had been dismantled on-site. The tree that the DH 108 had hit was also found, with the scar still visible. The earlier theory, that a faulty oxygen system was the cause, was ruled out by the coroner in his later report.^[citation needed]

Finally, on 1 May 1950, during low-speed sideslip and stall tests, the first prototype, TG283, was lost in a crash at Hartley Wintney killing the pilot, Sqn Ldr George E.C. Genders AFC DFM. After abandoning the aircraft at low altitude in an inverted spin, his parachute failed to open in time. In all, 480 flights had been made by the three Swallows.^[11]

Legacy

The DH108 established a number of "firsts" for a British aircraft: it was the first British swept-winged jet aircraft and the first British tailless jet aircraft.

Operators

 United Kingdom

• Royal Aircraft Establishment

Specifications (DH 108 VW120: third prototype)

General characteristics

• Length: 29 ft 9.5 in (9.081 m)
• Wingspan: 39 ft (12 m)
• Wing area: 327.86 sq ft (30.459 m²)
• Empty weight: 8,940 lb (4,055 kg)
• Powerplant: 1 ×
  de Havilland Goblin 4
  centrifugal compressor jet engine, 3,738 lbf (16.63 kN) thrust

Performance

• Maximum speed: 677 mph (1,090 km/h, 588 kn)
• Range: 730 mi (1,170 km, 630 nmi)
• Service ceiling: 35,425 ft (10,798 m)
• Wing loading: 27 lb/sq ft (130 kg/m²)
• Thrust/weight: 0.42

See also