Designed by Geoffrey de Havilland to be a two-seat light bomber powered by a BHP engine. First prototype flew in August 1916, but as the BHP engine proved to be weak it required a major redesign and DH.4 was adapted to be equipped with a Rolls Royce Eagle engine. First order for 50 planes powered by Eagle III engine (250hp) was placed at the end of 1916.
Basically an all-wooden construction tractor biplane, Airplane armament consisted of one forward-firing Vickers synchronized machine gun and one or two Lewis guns on the Scarff ring mount at the observer position. It could carry up to 460 pounds of bombs on external racks on wings or central position.
Due to shortages of Rolls Royce engines the production airplanes were also fitted with BHP (230hp), RAF3A (200hp), the Siddeley Puma (230hp) and the 260hp Fiat, yet none of the alternative powered DH.4\s could match the Rolls Royce powered machines. First DH.4 in frontline service were supplied to No.55 squadron on March 1917; it was the first RFC squadron fully equipped with this type. Till the end of 1917, a total of 6 squadrons were equipped with DH.4\s. It also was used by RNAS squadrons for naval operations for recon and anti-submarine use.
Reported to be pleasant to fly and easy to operate, the crews loved it because of its speed and maneuverability (the only “flaw” noted by its crews was the fuel tank placed between pilot and observer cockpits which caused communication problems between them). Due to its abilities, it was often used without fighter cover as its speed and good altitude performance allowed it to survive. Mostly used as a light day-bomber, it also could carry radio equipment for artillery observation duties and camera equipment for photo-reconnaissance missions.
Produced by Airco, F.W. Berwick and Co, Glendower Aircraft Company, Palladium Autocars, Vulcan Motor and Engineering, and the Westland Aircraft Works in the UK, a total of 1,449 aircraft were built in the UK for the RFC and RNAS through the end of the war.
Triebwerk: V-type-12-Zylinder Rolls Royce Eagle VII
Leistung: 275 hp (320hp at 1800 RPM)
Dimensionen:
Hohe: 3100 mm
Lange: 9200 mm
Spannweite: 12916 mm
Flugelflache: 40 m²
Gewicht:
Leer: 1088 kg
Treibstoffkapazität: 249 Liter
Ölkapazität: 27,3 Liter
Startgewicht ohne Bombenzuladung: 1588 kg
Fluggeschwindigkeit (IAS), ohne Bomben:
Meeresspiegel - 200 km/h
1000 - 189 km/h
2000 - 178 km/h
3000 - 166 km/h
4000 - 154 km/h
5000 - 140 km/h
Steigzeit, volle Treibstoffzuladung, ohne Bomben:
1000 m - 3 Min. 23 Sek.
2000 m - 7 Min. 7 Sek.
3000 m - 11 Min. 47 Sek.
4000 m - 17 Min. 52 Sek.
5000 m - 27 Min.
Dienstgipfelhöhe: 6800 m
Reichweite: 3 h.
Bewaffnung:
Starre Bewaffnung nach vorne: 1 x Vickers Mk.I 7,69 mm, 500 Schuss pro Magazin.
Heckschützenposition: 1 x Lewis 7,69 mm, 8 Trommeln mit jeweils 97 Schuss.
Bombenzuladungsmöglichkeiten:
12 x 20lb (109 kg)
8 x 20lb + 2 x 112lb (175 kg)
4 x 112lb (203,4 kg)
2 x 112lb (101,7 kg)
2 x 230lb (208,8 kg)
Maximale Zuladung: 208,8 kg
Referenzen
1) Air Board Data Charts, 1917.
2) Notes on the prediction and analysis of airplane performance, reports and memoranda no.474, may 1918, tables no. 10 and 11.
3) Windsock Datafile Special - Airco DH.4 Vol.1, by J.M. Bruce.
4) Rolls Royce engine charts, 1917.
5) WWI Aeroplanes data, by J.M. Bruce.
6) Various NACA reports.
Aldis Teleskopvisier
Zusätzliches Gewicht: 2 kg
12 x 24 lb Cooper Bomben (11 kg)
Zusätzliches Gewicht: 167 kg
Gewicht der Munition: 131 kg
Gewicht der Abwurfwaffenroste: 36 kg
Geschwindigkeitsverlust vor Abwurf: 7 km/h
Geschwindigkeitsverlust nach Abwurf: 3 km/h
4 x 112 lb H.E.R.L. Bomben (51 kg)
Zusätzliches Gewicht: 22 kg
Gewicht der Munition: 204 kg
Gewicht der Abwurfwaffenroste: 24 kg
Geschwindigkeitsverlust vor Abwurf: 8 km/h
Geschwindigkeitsverlust nach Abwurf: 4 km/h
2 x 230 lb H.E.R.F.C. Bomben (104 kg)
Zusätzliches Gewicht: 224 kg
Gewicht der Munition: 208 kg
Gewicht der Abwurfwaffenroste: 16 kg
Geschwindigkeitsverlust vor Abwurf: 5 km/h
Geschwindigkeitsverlust nach Abwurf: 3 km/h
Glühlampe zum Beleuchten des Instrumentenbrettes bei Nachteinsätzen
Zusätzliches Gewicht: 1 kg
Anzeige mit Nadel für die Treibstoffmenge (0-30 Gallons)
Zusätzliches Gewicht: 1 kg
Kamera zum Aufnehmen von Luftbildern
Zusätzliches Gewicht: 10 kg
Funkgerät
Zusätzliches Gewicht: 10 kg
Zwei überflügeln montierte zusätzliche Lewis-Maschinengewehre ohne wechselbarer Position.
Munition: 194 7,69mm Patronen (2 Trommeln mit jeweils 97 Schuss)
Geschossgewicht: 11 g
Mündungsgeschwindigkeit: 745 m/s
Feuerrate: 550 Schuss/min
Gewicht der Waffe: 15 kg (ohne Munitionstrommel)
Gewicht der Halterung: 6 kg
Gewicht der Munition: 10 kg
Gseamtgewicht: 31 kg
Geschätzter Geschwindigkeitsverlust: 5 km/h
Scarff ring turret with twin Lewis MG
Ammo: 776 of 7.69mm rounds (8 drums with 97 rounds in each)
Projectile weight: 11 g
Muzzle velocity: 745 m/s
Rate of fire: 550 rpm
Guns weight: 15 kg (w/o ammo drums)
Mount weight: 12 kg
Ammo weight: 32 kg
Total weight: 59 kg
Estimated speed loss: 2 km/h
Twin fixed forward firing Vickers guns.
Ammo: 1000 of 7.69mm rounds (500 rounds for each gun)
Geschossgewicht: 11 g
Mündungsgeschwindigkeit: 745 m/s
Feuerrate: 750 Schuss/min
Gewicht der Waffe: 13 kg (ohne Munitionstrommel)
Gewicht der Halterung: 4 kg
Gewicht der Munition: 21 kg
Gseamtgewicht: 38 kg