A drone (120; 1900) comprising: a retractable suspension member (135; 1902); a coupling member (140; 1904) attached to an end of the retractable suspension member, wherein the coupling member: is configured to engage with a coupling counterpart (250; 1912) affixed to a top wall of a container (1110; 1906); is gravity activated to hold or release the container from the retractable suspension member; and is configured to securely hold the container onto the retractable suspension member in an event the gravitational force exerted on the coupling member due to the weight of the container exceeds a first specified value and release the container from the retractable suspension member in an event the gravitational force exerted on the coupling member due to the weight of the container drops below a second specified value; a package delivery module configured to control a movement of the retractable suspension member so as to lower and raise the coupling member; a container housing affixed to the drone, wherein the container housing is adapted to receive at least a portion of the container; and a spool brake; wherein, in use: the package delivery module retracts the at least a portion of the container into the container housing; and the spool brake prevents the retractable suspension member from lowering and thereby prevents the container from lowering. a retractable suspension member (135; 1902); a coupling member (140; 1904) attached to an end of the retractable suspension member, wherein the coupling member: is configured to engage with a coupling counterpart (250; 1912) affixed to a top wall of a container (1110; 1906); is gravity activated to hold or release the container from the retractable suspension member; and is configured to securely hold the container onto the retractable suspension member in an event the gravitational force exerted on the coupling member due to the weight of the container exceeds a first specified value and release the container from the retractable suspension member in an event the gravitational force exerted on the coupling member due to the weight of the container drops below a second specified value; is configured to engage with a coupling counterpart (250; 1912) affixed to a top wall of a container (1110; 1906); is gravity activated to hold or release the container from the retractable suspension member; and is configured to securely hold the container onto the retractable suspension member in an event the gravitational force exerted on the coupling member due to the weight of the container exceeds a first specified value and release the container from the retractable suspension member in an event the gravitational force exerted on the coupling member due to the weight of the container drops below a second specified value; a package delivery module configured to control a movement of the retractable suspension member so as to lower and raise the coupling member; a container housing affixed to the drone, wherein the container housing is adapted to receive at least a portion of the container; and a spool brake; wherein, in use: the package delivery module retracts the at least a portion of the container into the container housing; and the spool brake prevents the retractable suspension member from lowering and thereby prevents the container from lowering. the package delivery module retracts the at least a portion of the container into the container housing; and the spool brake prevents the retractable suspension member from lowering and thereby prevents the container from lowering.