Md. Code, Transportation § 5-503

(a) As to each airport, in the establishment of airport zoning districts or the adoption or amendment of its airport zoning regulations, the Administration shall consider, among other things, to the extent that they affect and in order to promote the public health, safety, order, or security, the following:

(1) The character of the flying operations conducted or expected to be conducted at the airport;

(2) The surrounding terrain;

(3) The height of existing structures and trees or other vegetation in the vicinity;

(4) The feasibility of lowering or removing existing structures or trees or other vegetation in the vicinity;

(5) As to the aerial approaches necessary for safe flying operations at the airport, the opinion of the federal agency charged with fostering civil aeronautics;

(6) The risks associated with aerial traffic at the airport;

(7) The type, size, weight, and load capacity of aircraft that use or might use the airport;

(8) The weather conditions generally prevailing in the vicinity;

(9) The size and layout of the landing area of the airport; and

(10) The present and future needs of the inhabitants of this State with reference to the use of the airport for public transportation.

(b) An airport zoning regulation adopted under this subtitle may not:

(1) Require the removal or alteration of any structure that, as it existed when the regulation was adopted, did not conform to the regulation; or

(2) Otherwise interfere with the continuance of any nonconforming use.

(c) Except as otherwise provided in this subtitle, an airport zoning district or airport zoning regulation adopted under this subtitle may not apply to any property located more than 3 miles beyond the outer perimeter of any airport.