Abstract: Assemblies and methods are provided to allow a temporary alternate door (e.g., an observation door for use during search and rescue (SAR) missions) may be placed in a fuselage opening normally closed by a dedicated personnel door. The assembly may be provided with a central support pole attachable to interior structure of the aircraft fuselage so as to be disposed in an upright position within an interior of the aircraft fuselage (e.g., within the aircraft's cargo hold), and at least one stand-by alternate door (e.g., an observation door) which is sized and configured to be operatively accepted by the aircraft fuselage door opening when the dedicated primary aircraft door is in an opened and stowed condition. Typically a pair of stand-by alternate doors are removably connected to the central support pole so as to be capable of being movably deployed into a position to close the aircraft fuselage opening when disconnected from the central support pole.

Abstract: Assemblies and methods are provided to allow a temporary alternate door (e.g., an observation door for use during search and rescue (SAR) missions) may be placed in a fuselage opening normally closed by a dedicated personnel door. The assembly may be provided with a central support pole attachable to interior structure of the aircraft fuselage so as to be disposed in an upright position within an interior of the aircraft fuselage (e.g., within the aircraft's cargo hold), and at least one stand-by alternate door (e.g., an observation door) which is sized and configured to be operatively accepted by the aircraft fuselage door opening when the dedicated primary aircraft door is in an opened and stowed condition. Typically a pair of stand-by alternate doors are removably connected to the central support pole so as to be capable of being movably deployed into a position to close the aircraft fuselage opening when disconnected from the central support pole.

Abstract: The disclosed embodiments herein are generally directed toward force-balancing mechanisms for weighted members and/or loads. According to one embodiment, the force-balancing mechanism includes at least one gear rack, at least one spring assembly comprising a spring member operatively connected to the at least one gear rack, a pinion gear intermeshed with the at least one gear rack; and a variable radius cam. Rotation of the cam causes the pinion gear to rotate to thereby in turn linearly drive the at least one gear rack and accumulate spring force of the spring member. The spring member may be a compression or a tension spring. Preferably, the spring member is a compression spring.

Abstract: The disclosed embodiments herein are generally directed toward force-balancing mechanisms for weighted members and/or loads. According to one embodiment, the force-balancing mechanism includes at least one gear rack, at least one spring assembly comprising a spring member operatively connected to the at least one gear rack, a pinion gear intermeshed with the at least one gear rack; and a variable radius cam. Rotation of the cam causes the pinion gear to rotate to thereby in turn linearly drive the at least one gear rack and accumulate spring force of the spring member. The spring member may be a compression or a tension spring. Preferably, the spring member is a compression spring.