The Soviet Union built large numbers of an unlicensed copy of the DH.9A, the R-1. After the production of 20 DH.4 copies, followed by about 200 copies of the DH.9 powered by the Mercedes D.IV engine (also designated R-1) and a further 130 powered by the Siddeley Puma (designated R-2), a copy of the DH.9A powered by the M-5 engine, a Soviet copy of the DH.9A's Liberty, entered production in 1924. The Polikarpov R-4 was a modification of the R-1, with the engine lowered and moved forward by 140 mm (5.5 in) to improve both the forward visibility and the C.G position. The nose shape was improved by fairing and by installing a retractable ventral radiator. Overall length was increased by 389 mm (15.3 in). Landing legs were changed from wood to steel. Testing showed insufficient improvement over the R-1 to justify production but late R-1s incorporated some of the modifications.
The file contains the unit and pcx files. Model is not my own creation. Wyrmshadow helped with the animation files. I merely put the pieces together and cleaned up the model for CivIII and added some what if pieces. A big thanks to everyone that helped out!