(1) It is desired to remove, lower, or otherwise terminate a nonconforming structure or use; or (2) the approach protection necessary cannot, because of constitutional limitations, be provided by airport zoning regulations under this chapter; or (3) it appears advisable that the necessary approach protection be provided by acquisition of property rights rather than by airport zoning regulations, the political subdivision within which the property or nonconforming use is located or the political subdivision owning the airport or served by it may acquire, by purchase, grant, or condemnation in the manner provided by the law under which political subdivisions are authorized to acquire real property for public purposes, such air right, avigation casement [easement], or other estate or interest in the property or nonconforming structure or use in question as may be necessary to effectuate the purposes of this chapter.