Deer Valley Airport based pilot claims helicopter operations on north side of airport are unsafe.

Narrative

I operate aircraft on the north side of Phoenix Deer Valley airport. Over the past year; the Deer Valley Tower has begun clearing helicopter takeoffs and landings on the ramp next to the hangars and I believe that these operations are both hazardous to myself; and any taxiing aircraft on the North ramp. When the Tower clears them for takeoff to the North; they back taxi down the center of the ramp and turn around and do their takeoff run to the North. This operation is completely out of visual contact with the Tower; and I believe a serious potential hazard to any aircraft taxiing out of a side taxiway; coming around the corner only to be taxiing head-on into a helicopter in a low altitude takeoff run.When the Tower clears them for a takeoff to the East; or South; they do their takeoff run to the south and immediately turn left directly over the hangars; sometimes as low as 30-40 FT. I am of the opinion that both of these practices are dangerous to the local tenants and involved aircraft; and are probably not within guidelines for safe operations.