This post is also available in:
Français (French) 
Español (Spanish)
This R&D enables you to unlock different services in order to activate them on the Services page.
Each research has two levels, the second one is always a improved version of the first one, that is to say more luxury.
For each level, researches represented by the same thumbnail deal with the same service and enable different specializations. Thus for each service, it is recommended to buy only one of the two researches, unless you want to obtain the bonus research.
The bonus researches of this R&D grant airline characteristic points directly. Thus it is not necessary to configure them on the Services page, unlike classic researches which are on the same page.
