A helicopter-carried rescue apparatus comprising a collapsible net assembly having an axis therethrough and, first and second axial ends, said assembly being biased by its own weight to have an upright position with said axis in a vertical direction and said first and second axial ends disposed at the upper and lower ends, respectively, of the net assembly, said net assembly including:
- a flexible net;
- a collapsible frame structure having said net fitted thereto, said net being collapsible about said axis between a fully collapsed condition having said net folded about said axis and a fully expanded condition having said net spread out about said axis, the net spread out having a portion stretched on a plane substantially perpendicular to said axis and proximate to said second axial end of the net assembly, and a hoisting system having a lifting mechanism for installation on a helicopter, said mechanism having at least one flexible hoisting line fastened at one end to said lifting mechanism and at the other end to said net assembly, for suspending the net assembly in said upright position below the helicopter during flight, said frame structure being defined by a support member located in proximity to said first axial end of the net assembly, substantially perpendicular to said axis of the net assembly and having an axis substantially coincident with the axis of the net assembly;
- a plurality of main ribs pivotally connected each at one end to said support member, extending radially outwardly from the support member and away from said first axial end of the net assembly, the individual main ribs being pivotable around said axis of the net assembly between first angular positions closest to the axis of the net assembly and second angular positions remotest from the axis of the net assembly, the frame structure being in the fully collapsed condition thereof when said main ribs are in said first angular positions and being in the fully expanded condition when the main ribs are in said second angular positions;
- externally threaded screw rod rotatably disposed about a center axis substantially coincident with said axis of the net assembly and which axially extends away from said support member toward said second axial end of the net assembly, said screw rod having a leading end at a predetermined distance from said second axial end of the net assembly when the frame is in the fully expanded condition thereof;
- an internally threaded guide member which is in mesh with said screw rod being movable on the screw rod in opposite directions parallel with the center axis of the screw rod as the screw rod is rotated in opposite directions about the center axis thereof;
- control ribs extending radially outwardly from said guide member, each pivotally connected at one end to the guide member and at the other end, to an intermediate portion of each of said main ribs, the individual control ribs being pivotable around the axis of the net assembly between first angular positions closest to said axis of the net assembly and second angular positions remotest from the axis of the net assembly and being in the first angular positions thereof, when the guide member is in a position closest to said leading end of the screw rod and in the second angular positions thereof when the guide member is in a position remotest from the leading end of the screw rod;
- and drive means mounted on said support member being operatively connected to said screw rod, the drive means being operative to drive the screw rod to rotate in either direction about the center axis as the rod drives said guide member to move in either direction along the screw rod.