De Havilland DH.86 Express
| De Havilland DH.86 | |
|---|---|
|
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| Type: | Airliner |
| Design country: | |
| Manufacturer: | |
| First flight: |
January 30, 1934 |
| Number of pieces: |
62 |
The De Havilland DH.86 Express was a four-engine airliner made by the British manufacturer de Havilland Aircraft Company in the 1930s. It could hold up to 12 passengers.
history
In 1933 the governments of Great Britain , India , Malaya , the Straits Settlements and Australia agreed to set up a joint airmail service. On September 23, 1933, Qantas , hoping for the route from Singapore to Brisbane , ordered a suitable aircraft from de Havilland. This order also joined Holymans Airways , which wanted to serve the connection to Tasmania. The DH.86 resulting from this order was given the unofficial name Express or Express Air Liner . The first flight took place on January 30, 1934.
construction
The DH.86 was a four-engine version of the successful De Havilland DH.84 Dragon , a double-decker made mostly of plywood . The new aircraft turned out to be a bit larger and, with its tapered wings and faired landing gear, offered less drag. It was powered by the manufacturer's most powerful engine, the new 200 hp Gipsy Six engine . In the long-haul version, up to ten passengers could be carried. The short-haul version intended for Holyman offered space for one pilot and twelve passengers.
In addition to the prototype, three other machines with only one pilot's seat were built. One of these machines, the "Miss Hobart" delivered to Holyman, was the fastest British airliner at the time. At the request of Qantas, the DH.86A was created, in which a second crew member could be accommodated behind the pilot. In the end, this version, with its elongated bow, turned out to be the faster aircraft.
After a series of crashes, the last of the 62 aircraft built got a redesigned tail unit. These machines were given the designation DH.86B.
The series of crashes
In the case of the DH.86, there were only four months between the design study and the test flights, as the aircraft had to be available in time for the airmail service to begin. In view of the low engine power, the aircraft was built very lightly. Under certain conditions, the DH.86 proved difficult to control, partly through the material to small-sized vertical stabilizer was due.
After numerous crashes, the Royal Air Force conducted a series of test flights in 1936. Although the results of this investigation led to the development of the improved version 86B, no modifications were ordered to the older aircraft. The series of crashes therefore continued over the next few years. The investigation report was only made available to the public forty years later.
The Australian government took the crashes as an opportunity in 1936 to temporarily revoke the DH.86's approval and to lift the import ban on American aircraft. The all-metal construction had long since prevailed in the competition models Boeing 247 , Douglas DC-2 and Douglas DC-3 .
Versions
- DH.86 : four-engine, medium-sized double-decker with a one-man cockpit
- DH.86A : improved version with two-man cockpit
- DH.86B : Version with modified rudder
use
The two-pilot version built for Imperial Airways was called Diana . These aircraft served connections in Europe and within the Empire , including the route from Khartoum to Lagos .
Another customer was the New Zealand airline Union Airways , which operated between Auckland , Palmerston North and Wellington . During the Second World War , these planes served as bombers and fought German auxiliary cruisers and Japanese shipping. After the war they came into the possession of the National Airways Corporation .
When the war broke out, fifteen machines were in service in Australia and New Guinea . Eight of these aircraft were taken over by the Royal Australian Air Force and were given RAAF serial numbers A31-1 to A31-8. During the war, some of them served as ambulance planes in the Middle East, the rest carried the wounded and other transports in Australia and New Guinea.
Most of the sixty-two DH.86 built were in service when the war broke out in Europe. During the war, these machines were used as liaison aircraft or to train navigators. Few survived the war.
Military users
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Technical data (DH.86A)
| Parameter | Data |
|---|---|
| crew | 2 |
| Passengers | 10-12 |
| length | 14.10 m |
| span | 19.70 m |
| height | 4.00 m |
| Empty weight | 2,830 kg |
| Takeoff weight | 4,650 kg |
| Top speed | 267 km / h |
| Service ceiling | 5,300 m |
| Range | 1,200 km |
| Engines | four 6-cylinder in-line engines de Havilland Gipsy Six with 150 kW each (approx. 200 hp) |
