Story is the 407 involved in this incident (ZS-RLS) was on the ground parked with the wind at between 20 to 25 knots at an angle of around 3 to 5 degrees on the right of the nose. The aircraft was shutting down and with the rotor speed at around 42 odd percent, there were half a dozen or so knocks which was the tail rotor hitting the tail. Initial suspicion was that the pilot had put peddles is to reduce the rotor speed but after questioning, it was discovered that the rudders were level.
Where could the problem lie?
What caused this?
No-one has any answers yet! Just a whole lot of shoulder shrugging and confused expressions.