Hughes 500 - your friendly Ops Inspector should be able to point you i the right direction.
I'm sorry I wasn't very clear with my description of double angle. EASA have been very good and produced the following from the European Helicopter Safety Team. It describes and shows the double angle.
Interesting to note how it describes arrivals and departures IN the 'avoid curve' such as Vertical & Towering...
http://easa.europa.eu/essi/ehest/wp-...ations-v10.pdf