How about adopting common sense?
Any licencensed fire arm certificate holder will know the restrictions that apply when carrying weapons from A to B in their car, much the same applies when going by air.
If it's your own aeroplane, be discreet, inform the aerodrome authority in advance, and transport it in it's proper carrying case.
If you've chartered the aeroplane, then you are legally obliged to inform the operator when you make the booking, they will take appropriate steps to comply with the law.
We get shooting parties into our place on a regular basis, and aside from a few sore arses on return flights, as a result of mis directed lead pellets on the grouse moors, we never have a problem.