W, I am not a lawyer, and what I have to say may be worth no more than you are paying for it. (I leave to you to judge whether other nonlawyer advice on here is worth anything more.)
With regard to emergency landings, as a glider pilot, I have sometimes had to do this. For any one airstrip, or open piece of ground that looks like it could be used for an emergency landing, the odds of anyone needing to do so without prior permission are extremely small. Nevertheless, it could happen.
My understanding is that in that event, you cannot in fact charge anything you like. If there is damage to people, livestock, crop, or property in any other way, you are of course entitled to restitution. This will be covered either by the pilot, or by his insurance. In the case of gliding land outs, the damage is almost always assessed as minimal and the pilot covers it out of his own pocket.
If there is any issue of a large amount of compensation, or the landlord demands that the glider is held by him until he is satisfied as to restitution the landlord is then taking responsibility for the glider and for ensuring that no further damage takes place to it while it is in his care if he refuses to allow the owner to collect it and sort out matters through insurance. I do not know of any case law on this matter, but that is my understanding, when the issue has been raised with legal eagles.
After all, if a vehicle runs off the road, and ends up in your front garden by accident, would you expect to be able to hold the vehicle until they pay a fortune whose size is of your choosing? I think that is a fair parallel.
Hope that helps to clarify the emergency arrival issue.
Chris N
Last edited by chrisN; 3rd Jun 2012 at 20:26.