FlightPathOBN,
Your comments are a real blast from the past. These types of helidecks should have been confined to the dustbin years ago. Annex 14 requires an unobstructed 180 degree obstacle clear segment (drop-down is possible) within a 210 degree limited limited obstacle segment (no obstacles above deck level).
Backing-up from a helideck is anathema because the 'habit' is an extremely dangerous one to have. As with this site, manoeuvring (in the sense of spot-turns) on helidecks is not recommended for the same reason that was explained in a previous post.
Hopefully the message that will be taken from this unfortunate incident is a rule of thumb (apart from the obvious one about required distances from obstacles) that, from a pilot's perspective:
- less than half of the helicopter is poking out of the side
- only a quarter of the helicopter is poking out of the front
- three quarters of the helicopter is poking out of the back
and
the type of spot turn (see my previous post) will dictate the amount of space required for the manoeuvre.
What I omitted to say in my last post was the pilot was saved because the
worst manoeuvre was employed. If a more economical one had been used, the tail rotor would have struck, not the main rotor.
Jim