A plane travels in a straight line from position A to position B in \(65 \mathrm{~min}\), moving at an average speed of \(400 \mathrm{~km} / \mathrm{h}\). In a car traveling from \(A\) to \(B\), the driver finds that the trip is \(600 \mathrm{~km}\) long by the route he is forced to take, which goes straight south for a certain distance and then straight west for a longer distance. At what angle south of west does the plane travel?