Test pilots of Russian Helicopters executed the first demonstration flight of the new Mil Mi-28UB attack helicopter on August 9, 2013. The new training version of the Mi-28N Night Hunter will be presented at the upcoming MAKS 2013 airshow in Moscow.
The Mi-28UB has a double set of controls that can be used for advanced training to qualify pilots for the Mi-28N (NATO-name Havok). The aircraft retains all features of the attack helicopter version. The UB-version made its first flight at the Rostvertol facilities, where the Mi-28N, the Mi-26(T) and the Mi-35M are made as well.
The main difference between the new Mi-28UB of the Mi-28N Night Hunter is a double-hydro-mechanical control system that allows you to control the helicopter from both the front-cockpit and rear-cabin. Normally the gunner/navigator sits in the front and the pilot in the back. In the Mi-28UB the trainee pilot takes pole position, with the instructor right behind him. The new helicopter has somewhat increased space for the instructor, with an expanded upper canopy cockpit, and newer seats.
Source: Вертолеты России (Russian Helicopters)