The board of county commissioners or the governing body of a city may exempt certain business property from ad valorem taxation. Qualifying properties must be used exclusively for manufacturing articles of commerce, conducting research, and development or storing goods or commodities that are sold or traded in interstate commerce. The tax exemption includes all or any portion of the appraised value of buildings and commensurate land and improvements. Property additions and expansions of existing businesses are eligible for the property tax exemption if new jobs are created as a result of such activity. A total or partial ad valorem tax exemption may be in effect for up to 10 years after the calendar year in which the business commences its operations or an expansion is completed (Art. 11, Sec. 13, Kansas Constitution). Items of machinery, equipment, materials and supplies used for business purposes with a retail cost when new of $1,500 or less are exempt from property tax. (K.S.A. 79-201w). Aircraft used predominantly in the conduct of the owner’s business or industry is exempt from property tax (K.S.A. 79-201k).