Hi Cyclone 7.
I have flown both the A109 and EC135 and both machines are very good.
The 135 has better OEI perf (in general) and would handle 5000ft and hot, the A109 is faster (retractable undercarriage) and is a great corporate machine (my experience is in the power, limited ops in the grand), but is less tolerant of every day wear and tear.
Both have a great OEI training mode that is very safe. Both are excellent choices. I prefer the 135 because of its single eng perf and roomier cockpit and cabin space (we operate at 500 ft AMSL and 38 deg c).
Availability is the key.......
Hope this helps,
Ex
