In respect of an aircraft,

(a) the person in whose name the aircraft is registered;

(b) a person in possession of the aircraft as purchaser under a conditional sale or hire-purchase agreement that reserves to the vendor the title to the aircraft until payment of the purchase price or the performance of certain conditions;

(c) a person in possession of the aircraft as chattel mortgagor under a chattel mortgage; or

(d) a person in possession of the aircraft under a bona fide lease or agreement of hire.