Helicopter vortex wake is likely to be of lower intensity when landing than when taking off.
Firstly, a landing helicopter in a steady descent will have a lower angle of attack on the rotor blades than the same aircraft lifting to the hover and climbing.
Secondly, being at the end of its sector, it is likely to be at a lighter weight.
I don't work from ABZ but sometimes find myself more than a little bemused when I am given permission to hover taxy to line up on the runway then held in the hover for vortex wake reasons behind a departed fixed wing.
I'm already airborne.
