Hughes500
Rule6 states:
Manoeuvring helicopters
(i) Subject to paragraph (ii), a helicopter shall be exempt from the 500 feet rule if it is conducting manoeuvres, in accordance with normal aviation practice, within the boundaries of a licensed or Government aerodrome or, with the written permission of the CAA, at other sites.
(ii) When flying in accordance with this exemption the helicopter must not be operated closer than 60 metres to any persons, vessels, vehicles or structures located outside the aerodrome or site.
I reckon that makes it OK to do what you're doing and therefore not breaking the rules.
JJ