well, there are a few problems with it.
the first is that the helicopters do not fit on the platform. you cannot land 'around' a funnel, as the rotor might contact. the jetstream from the tail rotor and a bit from the main rotor is also deflected from the funnel area, which impacts the helicopter again, destabilising it. take a look at the clearance around the helicopter on the T43:
http://godfreydykes.info/TYPE%2043%20TWO.jpg
second, the gun platforms around that helideck have people standing on it. quite vulnerable, when the rotor passes you at only a few meters away.
third, there are huge masts and structures right next to the helideck, blocking forward and aft completely. again, blocking the airstream, but also making it impossible to move forward, aft, and to one side (the funnel) leaving only one side open to manouver..... while the helicopter is quite hard to control due to all the crosswinds and reflected air.
in short, the heliplat might work, yes, for something DASH sized, maybe a wasp, but anything bigger then that...... I doubt it possible, let alone doable.