Any airport authority or, if such authority has not been established, any board of park commissioners created pursuant to Kan. Stat. Ann. § 13-1346, or amendments thereto, may invest any portion of an airport fund not needed for immediate use, if operating pursuant to Kan. Stat. Ann. §§ 10-1116 and 79-2925, and amendments thereto, in investments authorized by Kan. Stat. Ann. § 12-1675, and amendments thereto, in the manner prescribed therein. All interest received from such investments plus the principal thereof shall be paid into the fund which provided the funds for the original investment.