What permission is needed to fly an aircraft to an airport classified as LRA? Can I just file a VFR flight plan, take off under VFR from somewhere in Florida, enter the class B with a clearance, and land there?
According to the FAR's
(2) Private aircraft. The pilots of private aircraft are required to secure permission to land from CBP following transmission of the advance notice of arrival via an electronic data interchange system approved by CBP, pursuant to § 122.22. Prior to departure as defined in § 122.22(a), from a foreign port or place, the pilot of a private aircraft must receive a message from CBP that landing rights have been granted for that aircraft at a particular airport.
This only matters if you are inbound from an out of country origin. An LRA airport is
Landing rights airport. A landing rights airport is any airport, other than an international airport or user fee airport, at which flights from a foreign area are given permission by Customs to land.