The Airco DH.4 in WW1
Driven by the needs of WW1, knowledge of aircraft design
advanced by leaps and bounds in just a few years. When Geoffrey de
Havilland designed this aircraft in 1916 the major lessons of
aircraft design had been learnt. The DH.4 first flew in August 1916
and entered service with the RFC (Royal Flying Corps) in France
during March 1917. The aircraft soon proved itself to be an
outstanding aircraft and arguably the best single engine bomber of
WW1. When America entered the war, they did so without any aircraft
designs equal to those in use by either side. They soon realised
that it would be an ideal aircraft for their own air force and
acquired the rights to manufacture it in the United States. Using
numerous companies, including Boeing, they built 9,500 DH.4's. 20%
of the US produced Airco DH.4 biplanes were sent to Europe, the rest
were used for numerous other duties within the US, Indeed the type
was so well thought of that the United States Army did not retire
it's last one until 1932.
The Airco DH.4 Design and Production
When Geoffrey de Havilland designed the Airco DH.4, he made
the unusual choice of placing the main fuel tank between the pilot
and co pilot. This had two obvious advantages; firstly the pilot was
not as far back in the aircraft, which gave better forward
visibility over the rather large and long engine, making take offs
and landings easier. Secondly the increased distance between the
pilot and observer reduced "blind-spots".
The central location of the main fuel tank also came with a few
disadvantages. The fuel system was a pressurised system, and while
this eliminated fuel pump issues it meant any leaks were also under
pressure. This included the main fuel tank which, if holed would
rapidly leak copious amounts of aviation fuel close to the pilot and
observer. This was a point in time when aircraft fires were all too
common and created a lot of criticism. Later models of the Airco
DH.4 abandoned the pressurised fuel tank system and instead used a
propeller slip stream powered fuel pump.
Several engines were tried in the Airco DH.4. The Rolls Royce Eagle
proved to be the best, with the American Liberty L-12 being a close
second. A total of approximately 6,200 DH.4's were produced, about
25% in the UK, most of the remainder in the US.
Various scale models, model kits and plans of this aircraft
have been available in the market place.
Airco DH.4 Biplane Specifications:
Airco DH.4 Crew: Pilot and observer
Airco DH.4 Length: 30 ft 8 in (9.35 m)
Airco DH.4 Wingspan: 43 feet 4 in (13.21 m)
Airco DH.4 Height: 11 ft (3.35 m)
Airco DH.4 Wing area: 434 ft² (40 m²)
Airco DH.4 Empty weight: 2,387 lb (1,085 kg)
Airco DH.4 Max takeoff weight: 3,472 lb (1,578 kg)
Airco DH.4 Engine: Single 375 hp (289 kW) Rolls-Royce Eagle
VII inline liquid cooled V12 piston engine
Airco DH.4 Maximum speed: 143 mph (230 km/h)
Airco DH.4 Range: 470 mi (770 km)
Airco DH.4 Service ceiling: 22,000 ft (6,700 m)
Airco DH.4 Biplane Armament:
Guns:
Single forward-firing Vickers .303 machine gun with
interrupter gear and a Lewis gun mounted on a Scarff ring around the
rear cockpit.
Bombs:
460 lb (210 kg). |
