I assume that this is a CAA licensed airfield, and I'm suprised that they haven't jumped on it.
We have helicopter training in similar circumstances, but it is done on a parallell taxiway which is separated from the main runway by around 600m.
At another airfield which I use, there is helicopter training adjacent to the runway, but simultaneous use is not permitted, (ie. if an aircraft is touching down, the helicopter must remain airborne).
It sounds pretty irresponsible to allow the 2 types to mix so closely.