N.H. Rev. Stat. § 12-G:20

Any mortgage, pledge, or security interest made by the authority under RSA 12-G:17-28 shall be valid and binding and shall be deemed continuously perfected for the purposes of RSA 382-A and all other laws from the time when the mortgage, pledge, or security interest is made. The airport property or revenues other than division revenues so mortgaged, pledged, or subjected to a security interest then held or thereafter acquired or received by the authority shall immediately be subject to the lien of such mortgage, pledge, or security interest without any physical delivery or segregation thereof or further act. The lien of such mortgage, pledge, or security interest shall be valid and binding against all parties having claims of any kind in tort, contract, or otherwise against the authority, irrespective of whether such parties have notice thereof. No such property or revenues may be used in a manner inconsistent with the terms governing such mortgage, pledge, or securities interest. Any agreement by which a pledge or security interest in personal property is created under RSA 12-G:17-28 shall be filed or recorded in the records of the secretary of state. Any mortgage or other agreement by which a security interest in real property is created under RSA 12-G:17-28 shall be filed with the register of deeds for Rockingham county.