(1) The school board of a union high school district or a common school district operating elementary and high school grades may contract:
(a) With the University of Wisconsin-Extension for extension courses for pupils enrolled in high school.
(b) With flight operator schools, approved by the U.S. civil aeronautics administration, for courses in flight instruction approved by the state superintendent.
(2) The cost of such contracts shall be paid out of the school district general fund.