14 CFR § 49.51 - Applicability.
This subpart applies to the recording of the following kinds of conveyances:
(a) Any lease, a notice of tax lien or other lien (except a notice of Federal tax lien referred to in § 49.17 (a), and any mortgage, equipment trust, contract of conditional sale, or other instrument executed for security purposes, which affects title to, or any interest in, any aircraft engine, propeller, or appliance maintained by or on behalf of an air carrier certificated under 49 U.S.C. 44705 for installation or use in aircraft, aircraft engines, or propellers, or any spare parts, maintained at a designated location or locations by or on behalf of such an air carrier.
(c) A release, cancellation, discharge, or satisfaction of a conveyance named in paragraph (a) or (b) of this section.