Are you suggesting the UK is not normal?
SASless: you know what I mean.. with all the restrictions and permissions for every little thing that is needed in the UK & many other European continent countries
Wouldn't have said that slingloading 500kg was really a Jet Ranger job?
Bladecrack: Yes sure. many JetRangers can lift 500 kg, expecially early model Agusta´s Bell 206A converted to B. It´s not easy lift and it help´s to have cool temp´s and some wind but it can be done in some JetRanger´s within limits.
I would suggest slinging the load vertically to avoid downflow and certainly long line. Close all roads that need to be crossed and get the job done with fast. Though the sling flight itself wouldn´t be much faster than about 20 kts I guess but hey it´s only one km.