General characteristics of Sopwith Swallow
Crew: 1
Length: 18 ft 9 in (5.72 m)
Wingspan: 28 ft 10 in (8.79 m)
Height: 10 ft 2 in (3.10 m)
Wing area: 160 sq ft (15 m2)
Empty weight: 889 lb (403 kg)
Gross weight: 1,420 lb (644 kg)
Powerplant: 1 × Le Rhône 9J nine-cylider rotary engine, 110 hp (82 kW)
Performance
Maximum speed: 113.5 mph (183 km/h; 99 kn) at 10,000 ft (3,050 m)
Service ceiling: 18,500 ft (5,639 m)
Time to altitude: 5 min 35 s to 6,500 ft (1,980 m)
This should be the new plane to combat the D8.


General characteristics of Fokker D VIII (D8)
Crew: 1
Length: 5.86 m (19 ft 3 in)
Wingspan: 8.34 m (27 ft 4 in)
Height: 2.6 m (8 ft 6 in)
Wing area: 10.7 m2 (115 sq ft)
Empty weight: 405 kg (893 lb)
Gross weight: 605 kg (1,334 lb)
Powerplant: 1 × Oberursel UR.II 9-cyl. air-cooled rotary piston engine, 82 kW (110 hp)
Performance
Maximum speed: 204 km/h (127 mph; 110 kn)
Endurance: 1.5 hours
Service ceiling: 6,000 m (19,685 ft)
Rate of climb: 8.333 m/s (1,640.4 ft/min)
Time to altitude:
1,000 m (3,281 ft) in 2 minutes
4,000 m (13,123 ft) in 10 minutes 45 seconds
Armament
Guns: 2 × 7.92 mm (0.312 in) Spandau MG08 machine guns

Its time we made some thing To fight the D8, though an ugly duckling, what I say is "Elegance is not the same as Effectiveness)

May I suggest that you check out McFate's thread regarding the Sopwith Camel. If I'm reading it correctly, we already have the in-game answer to the D8 as Zup already envisioned it to be. Though the Sopwith Swallow certainly looks sweet IMO.