Approach Angle:
CHC Intl uses 500ft/0.75nm
Landing on a deck of 100ft above sea level, this will give you a 5-5.5 deg approach angle. I think the 30 deg angle is close to an autorotation if you compare it to a normal ILS of 3 degrees. I also believe that the Norwegians have a Copter ILS that is calibrated at a 7-degree approach angle.
At least the 30-degree approach angle will give you sufficient height if you decide to use that. Safe flying!!
CJ
I have used the TAN Formula whereby the distance over the ground is 0.75nm = 4500ft (a) and the height above the deck is 400ft (0), this give the approach angle (Q) of about 5 degrees
Correct me if I am wrong.