I may be worthwhile to call the Chief and ask for clarification of his statements on the 500' lower limit. Let him know that the information you have is different as the FAA is instructing you to remain below 400' and you are just trying to reconcile it.
In Causby the Supreme Court deferred to Congress in setting the lower limit of public airspace, which at that time was 300'-1000' based on the situation, and this was crucial in determining whether the farmer's airspace was trespassed. And while, as others have pointed out, the majority opinion found "The landowner owns at least as much of the space above the ground as they can occupy or use in connection with the land.", the Court recognized that lower limit to public airspace set by the law of the time. They also recognized that the flight path of the aircraft for landing was authorized under the law as well, so rather than trespass it was considered an easement taken by the government, entitling the farmer to due compensation. United States v. Causby 328 U.S. 256 (1946)
While the law the Supreme Court referenced in their decision is depreciated (replaced by 14 CFR §91.119), their logic in determining the case isn't.
It remains to be sorted out how this actually applies to UASes and specifically to model aircraft operating under 336, as the law itself has drastically changed since that case was decided and now allows for operation of certain aircraft below proscribed minimums.
But are model aircraft even subject to that law, or does 336 preempt (which using the logic this case was decided with would mean airspace above the top of the tallest object on the property in question is considered public for the purposes of UAS operation)?
In Causby the Supreme Court deferred to Congress in setting the lower limit of public airspace, which at that time was 300'-1000' based on the situation, and this was crucial in determining whether the farmer's airspace was trespassed. And while, as others have pointed out, the majority opinion found "The landowner owns at least as much of the space above the ground as they can occupy or use in connection with the land.", the Court recognized that lower limit to public airspace set by the law of the time. They also recognized that the flight path of the aircraft for landing was authorized under the law as well, so rather than trespass it was considered an easement taken by the government, entitling the farmer to due compensation. United States v. Causby 328 U.S. 256 (1946)
While the law the Supreme Court referenced in their decision is depreciated (replaced by 14 CFR §91.119), their logic in determining the case isn't.
It remains to be sorted out how this actually applies to UASes and specifically to model aircraft operating under 336, as the law itself has drastically changed since that case was decided and now allows for operation of certain aircraft below proscribed minimums.
But are model aircraft even subject to that law, or does 336 preempt (which using the logic this case was decided with would mean airspace above the top of the tallest object on the property in question is considered public for the purposes of UAS operation)?