A helicopter is on a 150 NM leg to an off-shore oil rig. Its TAS is 130 kt with a 20 kt tailwind, its endurance is 3h30min without reserve. Upon reaching destination, it is asked to proceed outbound to locate a ship in distress, on a track which gives a 15 kt tailwind. Maintaining zero reserve on return to the oil rig, the helicopter can fly outbound for distance of: