Airco (de Havilland) DH.4
The DH.4 was a very successful two-seat day bomber built by the British (1,449 planes) and Americans (3,227 planes built under license). It was the only British plane to also be used by the French (1,885 American-built DH-4s). It was employed beginning in early 1917, and used until war's end. Post war, the DH.4 saw use as a passenger transport, photographic/firespotting mount, mailcarrier, experimental aircraft (it was the first plane to be refueled inflight) and had an ongoing military career in Belgium, Greece, Japan, Spain, and Latin American countries.
The plane was very sturdy, and could take many bullet holes without losing structural integrity. Its main weakness was the spacing between the pilot and observer. The fuel tank was placed between the crew positions, and the resulting gap made inflight communication between the crew difficult--a very large liability when intercepted by enemy fighters and forced into combat.
The plane has a historical endurance of 3 hours and 45 minutes. The plane uses 14 gallons of aviation fuel per hour at routine usage. A full load of fuel and ammo (not including bombs) costs $48.20.
Airco de Havilland DH.4
Subassemblies: Light Fighter chassis +3; Medium Fighter wings with Biplane option +2; 2 fixed wheels +0.
Powertrain: 280-kW HP gasoline engine with 280-kW old prop and 66-gallon standard fuel tank [Body].
Occ.: 2 XCS Body
Cargo: 8 Body
Armor F RL B T U
Body: 2/2W 2/2W 2/2W 2/2W 2/2W
Wings: 1/2C 1/2C 1/2C 1/2C 1/2C
Wheels: 2/3 2/3 2/3 2/3 2/3
2xAircraft LMG/.303 Vickers [Body:F] (875 rounds each).*
2xAircraft LMG/.303 Lewis [Body:B] (875 rounds each).*
460 lbs. of Bombs [Body and Wings:U].
Body: 460-lb. Hardpoint [Body and Wings:U], Casemate mount for rear guns.
Size: 30'x42'x11' Payload: 0.54 tons Lwt.: 1.74 tons
Volume: 144 Maint.: 95 hours Cost: $4,465
HT: 6. HPs: 25 Body, 80 each Wing, 8 each Wheel.
aSpeed: 143 aAccel: 4 aDecel: 17 aMR: 4 aSR: 1
Stall Speed: 39 mph. Take Off Run: 152 yards. Landing Run: 152 yards.
gSpeed: 203 gAccel: 10 gDecel: 10 gMR: 1.25 gSR: 2
Ground Pressure: Very High. 1/8 Off-Road Speed.
Historical wing area was 434 sf. Chassis and wing weight, costs, and HPs were halved to lower design weight; it was decreased another 10% to the historical. Design aSpeed as 130 mph. Historical values for wing area and loaded weight were used for performance calculations. The forward fixed Vickers MGs are synchronized, lowering RoF by 10% (see p. W:MP8).
The DH.4A was a civil design used after the war for passenger transport. It carried 2 passengers in an enclosed cabin behind the cockpit.
The DH-4A was the American-built version. It had a higher fuel capacity, and the forward fixed guns were 7.62mm Marlin machine guns.
The DH-4B reversed the position of the fuel tank and the pilot's cockpit, moving the crew closer together.
The DH.4R was a single plane built for racing. The engine was upgraded to a 335.5-kW Napier, allowing a top speed of 150 mph.
From the Aerodrome for GURPS
© 2008 by Jim Antonicic