SATCO Biggin
Is it the law that grass has to be kept between 6 and 8 inches or is it a recommended practice.?
If it is the latter then presumably you could have it cut to bowling green height.
Trouble is that should an a/c suffer an accident caused by a bird strike and the owner resort to litigation then your failure to meet best practice woulld count against you as in the case of Fred Olsen Lines o/y vs Norwich Airport.
What is your bird hazard assesment? Does it show the likely levels of risk?
If cutting the grass has no adverse effect on bird numbers or if you have Britains best bird control unit then carry on I say.
If not I'd reach for CAP683 and just accept that for the greater good your greensward will have to offend your eyes
Sir George Cayley