I have read that under normal circumstances two different controllers (and two different radio frequencies) were used. One to control helicopters and another to control airplanes. This seems to me to make things even more dangerous because the helicopters would not be able to hear what is happening with the plane traffic and vice versa. Therefore I think the resulting ignorance should be considered a prime factor in this accident.
These problems are easily solved. Don't allow a helicopter to fly across the flight path of a major airport! There are so many planes taking off and landing at that airport that it is easy to become confused. If you watch the video of the collision, there is another plane ascending just above the one that was hit. Flying a helicopter there is like trying to run across the racetrack during the Daytona 500. And doing that at night with night vision goggles on! Good grief. Eventually something bad is going to happen.
