De Havilland DH 108 Swallow by Planet Models
1/72 scale
Kit No. PLT046
Cost: $50 – $70 (aftermarket, out of production)
Decals: One version – RAF High Speed Research Programme
Comments: Injection molded resin, engraved panel lines, vacuform canopy
History
The elegant — and highly lethal — de Havilland DH 108 “Swallow” was an important British experimental research aircraft of the late 1940’s designed by John Carver Meadows Frost in October 1945. It had its origins in a mission undertaken by a team from de Havilland Aircraft to travel to Germany within two weeks of the end of World War II to interview senior German aircraft designers. The DH108 established a number of “firsts” in British aviation. It was the first British swept-winged jet aircraft and the first British tailless jet aircraft.
The DH 108 featured a tailless, swept wing with a single vertical stabilizer. While it was a distinct aircraft, it was strongly influenced by the design of the wartime German Messerschmitt Me 163 Komet. It was initially designed to evaluate swept wing handling characteristics at low and high subsonic speeds for the proposed early tailless design of the Comet airliner. Three examples of the DH 108 were built to Air Ministry specification E.18/45. With the adoption of a conventional tail for the Comet, the aircraft were used instead to investigate swept wing handling up to supersonic speeds. All three prototypes would be lost in fatal crashes.
Employing the main fuselage section and engine of the de Havilland Vampire mated to a longer fuselage with a single tailfin 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 conceived as a tailless, swept-wing aircraft. Despite the Comet design subsequently taking on more conventional features, the value of testing the unique configuration to provide basic data for the DH.110 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.
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 in the wings. Although the Vampire fuselage was retained, as development continued, a revised nose and streamlined, reinforced canopy were incorporated.
The first DH 108 prototype, serial number TG283, had a 43-degree swept wing, flew on May 15, 1946 at RAF Woodbridge. Designed to investigate low-speed handling, it was capable of only 280 mph (450 km/h). De Havilland’s chief test pilot, Geoffrey de Havilland Jr., son of de Havilland company owner-designer Geoffrey de Havilland, gave a display flight in the DH 108 during the 1946 Society of British Aircraft Constructors (SBAC) airshow at Radlett.
The second, high-speed, prototype, TG306, which had a 45-degree swept wing incorporating automatic leading-edge Handley Page slats and was powered by a de Havilland Goblin 3 turbojet, flew soon afterwards, in June 1946. Modifications to the design included a longer more streamlined nose and a smaller canopy (framed by a strengthened metal fairing) facilitated by lowering the pilot’s seat. While being used to evaluate handling characteristics at high speed, on September 27, 1946, TG306 suffered a catastrophic structural failure which occurred in a dive from 10,000 ft (3,050 m) at Mach 0.9 and crashed in the Thames Estuary. The pilot, Geoffrey de Havilland Jr., was killed in the accident. The De Havilland Company, and of course the family, were devastated by the loss which was especially heartbreaking given that this followed the death of Geoffrey’s younger brother John, who was killed in a mid-air collision some 3 years earlier. However, while many found it very difficult to continue, they forged ahead with a third and final prototype (VW120).
Early wind tunnel testing had pointed to potentially dangerous flight behavior, but pitch oscillation at high speed had been unexpected. The subsequent accident investigation centered on a structural failure which occurred as air built up at Mach 0.9, pitching the aircraft into a shock stall that placed tremendous loads on the fuselage and wings. The main spar cracked at the roots causing the wings to immediately fold backwards. Similar oscillation at transonic speeds would destroy a delta-winged tailless aircraft, the Convair Sea Dart, during a flight test over San Diego Bay in December 1954.
After the loss of the second prototype, VW120 became the third and final prototype based on the newer Vampire F.5 fighter built at Hatfield. It differed from the first test aircraft in having an even more streamlined pointed nose and smaller reinforced canopy (lowering the pilot’s seat allowed for a more aerodynamic canopy shape to be employed). Power-boosted elevators had been specified as a means to control the pitch oscillations at the root of the earlier disaster. A more powerful Goblin 4 of 3,738 lbf (16.67 kN) thrust had the potential to push the DH 108 into the supersonic range. VW120 first flew on July 24, 1947 flown by John Cunningham, the wartime nightfighter ace.
Considered an important testbed for high-speed flight, VW120 was readied for an attempt at the World Speed Record then held by a Gloster Meteor at 616 mph (991 km/h). The second prototype, TG306, had been a backup for the attempt before it crashed. On April 12, 1948, VW120 established a new World Air Speed Record of 604.98 mph (974.02 km/h) on a 62-mile (100 km) circuit. Then, on September 6, 1948, John Derry is thought to have probably exceeded the speed of sound in a shallow dive from 40,000 ft (12,195 m) to 30,000 ft (9,145 m). The Royal Navy test pilot Captain Eric “Winkle” Brown, who escaped a crash in 1949, described the DH 108 as an aircraft that “had all the potential to beat the world speed record, and it had the possibility of breaking the sound barrier.” But it was also, Brown said, “a killer.”
In 1949, VW120 put on an aerial display at Farnborough and was placed third in the Society of British Aircraft Constructors Challenge Trophy Air Race before being turned over to the Ministry of Supply and test flown at RAE Farnborough. It was destroyed on February 15, 1950 in a crash near Brickhill, Buckinghamshire, killing its test pilot, Squadron Leader Stuart Muller-Rowland. The accident investigation at the time pointed, not to the aircraft, but to a faulty oxygen system that incapacitated the pilot. This was later revised to pinpoint a structural failure of the left wing as the plane dived.
The final chapter in the DH108 story was when the first aircraft (TG283) was lost in a crash at Hartley Wintney on May 1, 1950, and in which Squadron Leader Eric Genders was killed while attempting to abandon the aircraft. Over 480 test flights were carried out by the three experimental DH108 aircraft and they were instrumental in the development of modern jet aircraft of both military and civil design.
The Kit
Planet Models’ de Havilland DH 108 Swallow is injection molded in tan resin and consists of 26 parts, including a single vacuform canopy. The two largest parts by far are the upper and lower halves of the fuselage and wings which are integrally molded together. The lower wing features boxed in wheel wells for the main landing gear, just as the lower half of the fuselage has a boxed in well for the nose gear. The cockpit features individual parts for a seat, rear bulkhead, main instrument panel, control yoke, and two side panels including instrumentation. The main instrument panel in particular bears nice recessed detail.
The kit bears engraved panel lines and a separate vertical tail. All other parts, with the exception of the vacuform canopy, are encased within a paper-thin resin wafer. Some care will have to be taken in removing the more delicate parts, such as the landing gear and the two pitot tubes, without damaging them. The vacuform canopy is sufficiently well defined that the its distinctive side windows are plainly visible, which will facilitate painting and make for a more accurate completed model.
Markings
The decals are manufactured by Propagteam and are provided for the third and final prototype of the DH 108, VW 120, which broke the World Air Speed Record flying at 604.98 mph on April 12, 1948, before its own fatal crash nearly two years later.
Conclusion
This is a fairly simple resin kit with a modicum of detail that conjures up the mystery, danger, tragedy and adventure of man’s efforts to conquer the sound barrier. It appears to have been engineered with ease of construction in mind and is complemented by a set of first class decals. Highly recommended
References
- www.baesystems.com
- www.wikipedia.org
- Discovery Channel broadcast on de Havilland DH 108 (original air date unknown)