(1) That there has been an abandonment of the site as an airport site;
(2) That there has been a failure within two years, to develop the site as an airport or to comply with the conditions of the approval; or
(3) That prior to commencement of construction and because of change of physical or legal conditions or circumstances the site is no longer usable for the aviation purposes for which the approval was granted. [Formerly 492.200]