Research

Research is a menu option which leads to the game's technology lines. This allows players to use game currency to research aeronautic technology, and obtain improved planes. It also displays premium planes available for purchase with gold.

First technology line
Each new player starts their journey by choosing a nationally based technology line. Their research is restricted to that particular line until they have obtained two T4 aircraft.

Subsequent technology lines
After achieving two T4 planes, players may choose a second technology line to research. A third line becomes available when they have obtained two T5 aircraft, and the fourth line is available upon obtaining two  T6 planes. Any line may be chosen at each stage, and chosen lines may be advanced without developing additional research lines.

Using research points
Research points and silver are the two primary game currencies used for research. Free research points may be combined with an existing plane's research points (earned from battle) to advance through each tech tree. Gold can be used to convert regular research points from elite planes into free research points.

Players apply available research points to research advanced components on each research line. Once all available components have been obtained, the next tier aircraft becomes available. This plane is obtained with a combination of research points and silver.